• Metamaterials'2024
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9 September 2024 / Start time: 8 h 0 min
08:00 - 08:30 - Registration
08:30 - 09:00 - Opening Ceremony
09:00 - 10:00 - Plenary Session I
09:00 - Plenary Session I

Session chairperson(s): Romain Fleury

09:00 - 10:00 - Impedance Matching Schemes and Designed Wave Absorption Spectrum Plenary [Show abstract]
  • Ping Sheng, The Honk Kong University of Science and Technology, Honk Kong
I present three impedance-matching schemes in this talk for (a) air-borne sound, (b) underwater acoustics, and (c) microwaves. In (a), the scheme involves the integration of Fabry-Perot resonators that can lead to tunable absorption spectra. In (b), the combination of the causality constraint and the use of segmented structures is shown to lead to a solid absorber that can impedance-match with water, which sets the stage for resonator integration that can lead to either tunable or near-total underwater acoustic absorption. In (c), a new scheme for impedance matching with the vacuum is presented which involves the use of small metallic rings and their interaction with the image current to produce magnetic resonances. Adding series resistances to the ring can flatten the resonances’ spectra that leads to impedance matching over a broad frequency spectrum. The additional use of stacked hierarchical structures can further broaden the near-total absorption spectrum, extending from 3 to 40 GHz.
10:00 - 10:30 - Coffee Break (Monday Morning)
10:30 - 12:30 - Oral Sessions (Monday Morning)
10:30 - Space-time optics and imaging

Session chairperson(s): Vladimir Shalaev; Theodoros Koutserimpas

10:30 - 11:00 - Extreme Space-Time Optics Invited oral [Show abstract]
  • Vladimir Shalaev, Purdue University, USA
We first discuss all-optical modulation with single photons using electron avalanche, resulting in record-high nonlinearities. Then we show that transparent conducting oxides (TCOs) operating in the near-zero index (NZI) regime can provide strong single-cycle modulation, thus potentially enabling novel photonic time crystals.
11:00 - 11:15 - Seeing Through Time-Varying Scattering Media with an Epsilon-Near-Zero Medium Oral [Show abstract]
  • M. Zahirul Alam, Univerity of Ottawa, Canada
We exploit the large nonlinear optical responses of a subwavelength-thick epsilon-near-zero medium to image objects through scattering media. Our preliminary results hint at the possibility of simultaneous multicolor imaging through highly scattering media at a very high frame rate.
11:15 - 11:30 - Spatiotemporal control of waves for label-free super-resolution Oral [Show abstract]
  • Guillaume Noetinger , Laboratory of Wave Engineering, STI, EPFL, Switzerland
  • Fabrice Lemoult, Institut Langevin, ESPCI Paris, France
  • Sébastien M. Popoff, Institut Langevin, ESPCI Paris, France
The resolution of an imaging device based on the propagation of waves is ultimately limited by diffraction. To overcome this limit in a label-free way, we propose to incorporate a time-periodic spatio-temporal modulation in the acquisition process which consists in illuminating the object with a rotating source. The chosen modulation is based on the Doppler effect which applies to any type of wave. The temporal periodicity allows to multiplex the acquisition process: several images of the same object are acquired with different point spread function each of them being a vortex with a different topological charge. Combined with a reconstruction algorithm, the accumulation of information acquired allows to obtain super-resolved images. We demonstrate the experimental feasibility of this idea using audible acoustic waves. Our protocol is then successfully implemented in an optical confocal microscope to obtain super-resolved images. Using super-resolution imaging as an example, we show how spatio-temporal wavefrontshaping can generate wavefields with unusual features.
11:30 - 11:45 - Time-Periodic Optical Activity Oral [Show abstract]
  • Stefanos Koufidis, Imperial College London, United Kingdom
  • Theodoros Koutserimpas, Cornell University, United States of America
  • Francesco Monticone, Cornell University, United States of America
  • Martin McCall, Imperial College London, United Kingdom
Utilizing coupled-wave theory, we investigate light propagation in a time-periodic bi-isotropic medium. Unlike its static counterpart, the dynamic medium couples co-handed counter-propagating waves, thus forming two momentum gaps in the Brillouin diagram for non-constant impedance. Chirality provides control over the resonance centers, bandwidths, and amplification factors in a distinct fashion for orthogonal polarization states. By deriving simple formulae for the scattering coefficients of a finite “time-slab” of the considered medium, we showcase how extreme optical rotation leads to a negative refraction regime. Even for weak chirality, whereby the chiral scattering coefficients reach a similar level to the corresponding achiral medium, we illustrate how elliptical polarizations can significantly change field orientation, a manifestation of temporal optical activity, while simultaneously being amplified.
11:45 - 12:00 - Inversely Designed Spatiotemporal Metasurfaces to Steer the Spectral Flow of Light Oral [Show abstract]
  • Puneet Garg, Karlsruhe Institute of Technology, Germany
  • Thomas Sturges, Karlsruhe Institute of Technology, Germany
  • Jan Fischbach, Karlsruhe Institute of Technology, Germany
  • Carsten Rockstuhl, Karlsruhe Institute of Technology, Germany
In this contribution, we leverage a gradient-based inverse design framework to tailor the fields scattered from spatiotemporal metasurfaces on demand. These metasurfaces consist of a periodic arrangement of spheres characterized by a time-varying permittivity. Optimal temporal modulations are identified that, as an example, entirely suppress reflection losses from the spatiotemporal metasurfaces or transduce the light into a predefined frequency. We demonstrate that controlling the temporal modulation of spatiotemporal metasurfaces promises to provide a future generation of reconfigurable photonic devices.
12:00 - 12:15 - Temporal Discontinuity in Wire Media for Far-Field Subwavelength Imaging Oral [Show abstract]
  • Constantin Simovski, Aalto University, Finland
  • Sergei Tretyakov, Aalto University, Finland
  • Sajjad Mirmoosa, University of Eastern Finland, Finland
We investigate electromagnetic phenomena in wire media at fast switching between continuous and periodically cut wires. The results show that TEM waves with deeply subwavelength distributions of fields in the transverse plane are effectively converted into propagating waves whose frequencies and propagating directions encode information about the subwavelength field distribution before the switch. Via spectroscopic measurements of the intensity of all these propagating waves (time-refracted and time-reflected ones), one can find the amplitudes and phases of the initial wave package spatial spectrum. We suggest using this effect for THz wire media endoscopes, removing the need for tapered multi-wire cables that magnify the image up to minimal values imposed by existing THz detectors.
12:15 - 12:30 - Selective Field Enhancement via double Floquet Sheets by Tuning Modulation Phases Oral [Show abstract]
  • Yao-Ting Wang, National Sun Yat-sen University, Taiwan
  • Hsu-Hui Chou, National Sun Yat-sen University, Taiwan
We investigate the field strength amplification in a time-modulated double-layer system. The results show that a fast modulation exciting the phase-conjugated surface modes can amplify the transmitted waves. Also, tuning the modulation phase between the two sheets results in modal switches, thereby causing the selectivity effect of field enhancements.
10:30 - Acoustics of active, time-dependent and topological metamaterials

Session chairperson(s): Vassos Achilleos; JINGYI ZHANG

10:30 - 11:00 - Periodic Acoustic Waveguides Loaded With Active Scatterers And The Hatano-Nelson Model Invited oral [Show abstract]
  • Vassos Achilleos, Laboratoire d’Acoustique de l’Université du Mans (LAUM), UMR 6613, Institut d’Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, France., France
  • Anis Maddi, Laboratoire d’Acoustique de l’Université du Mans (LAUM), UMR 6613, Institut d’Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, France., France
  • Guillaume Penelet, Laboratoire d’Acoustique de l’Université du Mans (LAUM), UMR 6613, Institut d’Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, France., France
  • Yves Aurégan, Laboratoire d’Acoustique de l’Université du Mans (LAUM), UMR 6613, Institut d’Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, France., France
  • Vincent Pagneux, Laboratoire d’Acoustique de l’Université du Mans (LAUM), UMR 6613, Institut d’Acoustique - Graduate School (IA-GS), CNRS, Le Mans Université, France., France
In this work, we propose an exact broadband mapping of the Hatano-Nelson model in acoustics. We implement the theory using active scatterers and experimentally confirm the underlying phenomena i.e. the skin-modes, the loop-like spectrum for periodic boundaries and the exponential sensitivity to boundary conditions.
11:00 - 11:30 - Topological Sonic Fullerene Metamaterials Invited oral [Show abstract]
  • Danwei Liao, Nanjing University, China
  • Jingyi Zhang, IMDEA Materials, Spain
  • Shuochen Wang, Nanjing University, China
  • Zhiwang Zhang, Nanjing University, China
  • Alberto Cortijo, CSIC, Spain
  • Maria A. H. Vozmediano, CSIC, Spain
  • Francisco Guinea, IMDEA Nanociencia, Spain
  • Ying Cheng, Nanjing University, China
  • Xiaojun Liu, Nanjing University, China
  • Johan Christensen, IMDEA Materials, Spain
<p> A single-wall carbon nanotube can be viewed as a one-dimensional material created by rolling up a sheet of graphene. Its electronic band structure depends on the chirality, i.e., how the sheet has been rolled up, yet synthesizing the symmetry at will is rather challenging. We structure an artificial honeycomb lattice in both a zigzag and an armchair tube and explore their topological features for sound. Further, Buckminster Fuller lent his name to the C60 ball-shaped carbon allotrope, which is not only the roundest molecule in existence but also embodies 3D topological defects, whose properties we discuss using sound.</p>
11:30 - 11:45 - Acoustic Realization of Multiple Topological Corner Modes in a Coupling-inverted Phononic Crystal Oral [Show abstract]
  • Dongyi Wang, Hong Kong Baptist University, Hong Kong
  • Guancong Ma, Hong Kong Baptist University, Hong Kong
In this study, an unprecedented higher-order topological phase, supported by a multipole chiral number (MCN) greater than unity, is successfully achieved through coupling inversion in an acoustic crystal. This involves long-range couplings greater than the nearest-neighbor interactions. Sixteen topological corner modes, four at each corner, are experimentally detected within the mid-gap, which are shielded by an MCN=4.
11:45 - 12:00 - Polarized Floppy Modes in a 3D Topological Maxwell Lattice Oral [Show abstract]
  • Yi Chen, Karlsruher Institut für Technologie, Germany
  • James McInerney, University of Michigan, USA
  • Paul Krause, Karlsruher Institut für Technologie, Germany
  • Jonathan L. G. Schneider, Karlsruher Institut für Technologie, Germany
  • Martin Wegener, Karlsruher Institut für Technologie, Germany
  • Xiaoming Mao, University of Michigan, USA
We design a 3D topological Maxwell lattice that supports polarized floppy modes localized at one end of a finite-length metamaterial beam. We first study the design numerically and then present SEM images of fabricated samples. Experiments on the floppy modes are on-going and will be reported at the conference.
12:00 - 12:15 - Wave Acceleration in Two-Dimensional non-Hermitian Systems Oral [Show abstract]
  • Lea Sirota, Tel Aviv University, School of Mechanical Engineering, Israel
  • Sayan Jana, Tel Aviv University, School of Mechanical Engineering, Israel
  • Johnny Benisty, Tel Aviv University, School of Mechanical Engineering, Israel
We study wave propagation in non-Hermitian metamaterials, where the group velocity can be made fully controlled by the non-Hermiticity parameters. Specifically, the wavepackets can be made faster than their Hermitian counterparts upon request. This phenomenon was originally suggested in photonic systems, where a burst of light was propagated across a two-dimensional graphene-like stretched lattice constructed of coupled optical waveguides with gain and loss at the sites. Here, we show how to obtain this phenomenon in a stable form in active feedback-based metamaterials, on an acoustic platform in one dimension, and on electric circuit platfrom in two dimensions. The targeted stabilization approach that we propose directly serves this goal, helping to produce fast wavepackets propagating with a constant amplitude.
10:30 - Multifunctional intelligent surfaces

Session chairperson(s): Filiberto Bilotti; Sergei Tretyakov

10:30 - 11:00 - Metasurfaces aided signal processing for smart electromagnetic environments Invited oral [Show abstract]
  • Filiberto Bilotti, ROMA TRE University, Italy
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Mohsen Karamirad, ROMA TRE University, Italy
  • Michela Longhi, Niccolò Cusano University, Italy
  • Alessio Monti, ROMA TRE University, Italy
  • Davide Ramaccia, ROMA TRE University, Italy
  • Luca Stefanini, ROMA TRE University, Italy
  • Alessandro Toscano, ROMA TRE University, Italy
  • Stefano Vellucci, Niccolò Cusano University, Italy
In this contribution, we review our recent results on the concept of metasurface aided signal processing. The ability to control the properties of the metasurfaces and reconfigure their operation in real time allows enabling analog signal manipulation at the speed of light, avoiding frequency conversion, analog/digital conversion, and the execution of time-consuming digital signal processing numerical routines. The implementation of the metasurface aided signal processing concept in future smart electromagnetic environments will allow seamless ultra-high data rate communications boosted by a dramatic reduction of latency and jitter. Several examples of application of the metasurface aided signal processing concept are given to demonstrate its effectiveness in conceiving and implementing future wireless systems integrating communication and sensing capabilities.
11:00 - 11:15 - Micro-Doppler Encoding for Long-Range Drone Monitoring Oral [Show abstract]
  • Dmytro Vovchuk, Tel Aviv University, Israel
  • Mykola Khobzei, Yuriy Fedkovych Chernivtsi National University, Ukraine
  • Vladyslav Tkach, Yuriy Fedkovych Chernivtsi National University, Ukraine
  • Oleg Eliiashiv, Ivano-Frankivsk National Technical University of Oil and Gas, Ukraine
  • Omer Tzidki , Tel Aviv University, Israel
  • Konstantin Grotov, Tel Aviv University, Israel
  • Vjaceslavs Bobrovs , Riga Technical University, Latvia
  • Aviel Glam, Rafael Advanced Defense Systems Ltd., Israel
  • Pavel Ginzburg , Tel Aviv University, Israel
The massive deployment of small drones in urban airspaces calls for an immediate development of safety monitoring systems. Active solutions, such as live location reporting, are currently in use but heavily depend on continuous data connectivity, highlighting the need for reliable passive alternatives. Here we demonstrate a novel solution to tag the drone blades with electromagnetic stickers. Being driven into rotary motion, those stickers generate object-specific micro-Doppler signatures, which are interpretable by a surveillance radar from a 5km distance, while an untagged drone is barely seen from several 100s of meters.
11:15 - 11:30 - Reflective Intelligent Metasurface for Automatic Tracking of Mobile Targets Oral [Show abstract]
  • Nawel Meftah, LEME, UPL, Université Paris Nanterre, France
  • Badreddine Ratni, LEME, UPL, Université Paris Nanterre, France
  • Mohammed Nabil El Korso, Université Paris-Saclay, CNRS, CentraleSupélec, Laboratoire des signaux et systèmes, France
  • Shah Nawaz Burokur, LEME, UPL, Université Paris Nanterre, France
This work introduces an intelligent connected system, based on a programmable metasurface reflector combined with a microstrip patch antenna, capable of autonomously adjusting its electromagnetic properties to ensure dynamic tracking of mobile targets. The system first locates the moving target using GPS data retrieved from a real-time cloud platform, then calculates the desired radiation direction for the tracking and determines the appropriate phase profile, and finally generates the corresponding voltage modulation to be applied to the varactor diodes loaded on the metasurface. Experimental results highlight the responsiveness of the metasurface and its effectiveness in beamforming to optimize the tracking of mobile targets, opening the door to future autonomous wireless communication systems.
11:30 - 12:00 - Multifunctional Scanning Metasurface Panels Invited oral [Show abstract]
  • Sergei Tretyakov, Aalto University, Finland
In this review talk we will discuss recent research in the author's group and his collaborators on metasurfaces that can be configured for various functionalities by changing bulk components (variable capacitors, for example) in its meta-atoms. In contrast to periodical metasurfaces that require different periods for different functionalities, the introduced solutions allow full reconfigurability in geometrically fixed platforms.
12:00 - 12:30 - Passive Time-Varying Circuit-Based Metasurfaces and their Applications Invited oral [Show abstract]
  • Hiroki Wakatsuchi, Nagoya Institute of Technology, Japan
In this invited talk we report recently developed passive time-varying metasurfaces loaded with lumped circuit elements. These circuit-based metasurfaces provide an extra level of control over electromagnetic waves/signals even at the same frequency in accordance with the input pulse width.
10:30 - IR and optical metastructures

Session chairperson(s): Andrey Evlyukhin; Lior Michaeli

10:30 - 11:00 - Multipole Mechanisms of High-Q Resonances in Dielectric Metasurfaces Invited oral [Show abstract]
  • Andrey Evlyukhin, Cluster of Excellence PhoenixD, Leibniz University Hannover, Germany
  • Izzatjon Allayarov, Leibniz University Hannover, Germany
  • Antonio Calà Lesina, Leibniz University Hannover, Germany
  • Boris Chichkov, Leibniz University Hannover, Germany
The basic mechanisms of multipole electromagnetic resonances in dielectric and hybrid structures, as well as in metasurfaces, are discussed.
11:00 - 11:15 - Fast Multipole Algorithm for Electromagnetic Scattering from Particle Arrays using a Static Modes Basis Oral [Show abstract]
  • Emanuele Corsaro, Università di Napoli Federico II, Italy
  • Giovanni Miano, Università di Napoli Federico II, Italy
  • Antonello Tamburrino, Università di Cassino e del Lazio Meridionale, Italy
  • Salvatore Ventre, Università di Cassino e del Lazio Meridionale, Italy
  • Carlo Forestiere, Università di Napoli Federico II, Italy
We address the numerical solution of electromagnetic scattering problems in large particle arrays of subwavelength scatterers. We propose a fast numerical method specifically tailored to this problem, combining the use of the fast multiple method with the boundary integral equation method using an expansion in terms of static modes.
11:15 - 11:30 - Control of Optical Resonances in Hyperbolic Metamaterials Oral [Show abstract]
  • Olga Kochanowska, University of Warsaw, Poland
  • Tomasz J. Antosiewicz, University of Warsaw, Poland
The optical response of type II HMMs contains two dominant resonances: a radiative electric dipole (ED) and an absorbtive magnetic dipole coupled with electric quadrupole (MD-EQ). Here, I analyze hyperbolic nanodisk in terms of its sensitivity and derive the resonance condition for both ED and MD-EQ resonances.
11:30 - 12:00 - Direct Radiation Pressure Measurements for Lightsail Membranes Invited oral [Show abstract]
  • Lior Michaeli, California Institute of Technology, USA
  • Ramon Gao, California Institute of Technology, USA
  • Mike Kelzenberg, California Institute of Technology, USA
  • Claudio Hail, California Institute of Technology, USA
  • John Sader, California Institute of Technology, USA
  • Harry Atwater, California Institute of Technology, USA
Ultrathin lightsails, propelled to relativistic velocities by laser radiation pressure, are being actively explored as a new generation of interstellar space probes. In this presentation, I will outline our recent advancements in experimental characterization of ultrathin lightsail membranes. We perform sensitive force measurements on compliant silicon nitride membranes, which rely on three key components: rational design of the lightsail as a micromechanical resonator with enhanced mechanical susceptibility, displacement measurements using a noise-robust common-path interferometer with sub-picometer resolution, and an off-resonant, collimated driving scheme to excite quasi-static, linear dynamics. Moreover, we quantify the effect of edge scattering on optical forces in our angle-dependent measurements, which are calibrated to the incident driving power via micromechanical bolometry.
12:00 - 12:15 - All Dielectric metasurface for enhancing Mid-IR spectroscopy Oral [Show abstract]
  • Giovanni Piscopo, Munster Technological University Cork and Polytechinc University of Bari, Italy
  • Liam O'Faolain, Munster Technological University Cork, Ireland
  • Giovanni Magno, Polytechinc University of Bari, Italy
We propose the design of a novel all-dielectric high Q factor metasurface for the Mid-IR regime, offering control over the resonance position, the Q factor, and near field enhancement. These characteristics, along with a photolithography-compatible design, make it a highly effective platform for enhancing IR spectroscopy.
12:15 - 12:30 - Analyzis of Coupling Mechanisms by means of Local impedance in Hyperuniform Metasurfaces at Infrared Wavelengths Oral [Show abstract]
  • Eric Lheurette, University of Lille, France
  • Roman Buisine, University of Lille, France
  • David Dereudre, University of Lille, France
  • Ludovic Burgnies, University of Littoral Côte d'Opale, France
  • Olivier Vanbésien, University of Lille, France
  • Thibault Deletang, Sorbonne-University, France
  • Benoît Cluzel, University of Burgundy, France
In this communication, we analyze coupling mechanisms within hyperuniform structured metasurfaces by means of local impedance probing. It brings information on the localization properties as a function of distribution parameters (filling factor, disorder rate). This highlights the absorbing properties of those metasurfaces when illuminated by a plane wave. In particular, the resonating character of high density distributions tends to disappear to give rise to a quasi-linear impedance variation as a function of frequency. This can be explained by the combination of near-field capacititive and long-range magneto-inductive couplings.
10:30 - Chiral and bianisotropic structures

Session chairperson(s): Christos Argyropoulos; Carsten Rockstuhl

10:30 - 11:00 - L-shaped Silicon Metamaterials with Tailored and Enhanced Broadband Chiral Response Invited oral [Show abstract]
  • Christos Argyropoulos, The Pennsylvania State University, USA
  • Ufuk Kilic, University of Nebraska-Lincoln, USA
  • Matthew Hilfiker, University of Nebraska-Lincoln, USA
  • Alex Ruder, University of Nebraska-Lincoln, USA
  • Eva Schubert, University of Nebraska-Lincoln, USA
  • Mathias Schubert, University of Nebraska-Lincoln, USA
We experimentally realize all-dielectric L-shaped optical metamaterials based on tilted nanopillars that exhibit broadband and enhanced chirality in transmission. The reported strong chirality can be tailored in terms of both amplitude and operating frequency. It can also be switched off or on by simply varying the nanopillars shape and dimensions.
11:00 - 11:15 - Steering Loss and Extending Hyperbolic Wave Lifetimes with Shear Metasurfaces Oral [Show abstract]
  • Emanuele Galiffi, Advanced Science Research Center, Graduate Center, CUNY, USA
  • Simon Yves, Advanced Science Research Center, Graduate Center, CUNY, USA
  • Enrico M. Renzi, Advanced Science Research Center, Graduate Center, CUNY, USA
  • Xiang Ni, School of Physics, Central South University, China
  • Andrea Alu, Advanced Science Research Center, Graduate Center, CUNY, United States
Following the recent discovery of hyperbolic shear polaritons in monoclinic materials, we introduce hyperbolic shear metasurfaces, enabling loss mitigation for hyperbolic metamaterials. In these metastructures, thanks to the frequency-dependent rotation of the optical axis caused by the coupling between in-plane polarizability components, dissipative processes are diverted towards one hyperbolic arm, while dramatically reducing the effect of loss of the opposite one, leading to long-lived hyperbolic modes with enhanced tunability and directionality.
11:15 - 11:30 - Flat Pathways to the Maximum Optical Chirality Oral [Show abstract]
  • Maxim Gorkunov, Shubnikov Institute of Crystallography, Russia
  • Alexander Antonov, Shubnikov Institute of Crystallography, Russia
  • Egor Muljarov, Cardiff University, UK
  • Yuri Kivshar, Australian National University, Australia
<p> Dielectric metasurfaces with the eigenstates designed to selectively couple to circularly polarized light offer a game-changing platform for advances in chiral metaphotonics. Current designs rely on breaking the mirror symmetry by variable height or elevation of subwavelength meta-atoms, which is often technologically inconvenient. We discuss novel strategies for achieving the maximum optical chirality with metasurfaces composed of flat layers that can be processed with conventional two-dimensional lithography. Apart from extrinsic-chirality arrangements, which owe their broken mirror symmetry to a tilt of an optical setup, various single- and multi-layer designs are capable of maximizing intrinsic chirality at the normal incidence. We reveal that, under specific conditions, even weak symmetry-breaking effects of transparent substrates can lead to the maximum chirality.</p>
11:30 - 11:45 - Exceptional Points of Degeneracy in Coupled Chirowaveguides Oral [Show abstract]
  • Alice De Corte, University of Mons, Belgium
  • Stefanos Koufidis, Imperial College London, United Kingdom
  • Martin McCall, Imperial College London, United Kingdom
  • Bjorn Maes, University of Mons, Belgium
Exceptional points of degeneracy are critical junctures whereby eigenvalues and eigenvectors coalesce, resulting in unique dispersion features. In coupled waveguides, they occur via co-directional or contra-directional coupling. The former requires gain-loss modulation, akin to PT-symmetric gratings, whilst the latter relies on negative phase velocity. We illustrate forks in modal dispersion arising due to negative refraction induced by giant chirality. Such an approach circumvents the manufacturing challenges of balancing photon creation and absorption, while not requiring simultaneous negativity of permittivity and permeability. Meta-media with giant and controllable chirality offer exciting opportunities for light manipulation.
11:45 - 12:00 - Chiral Metamaterials with Strong and Broadband Pure THz Optical Activity: Theoretical and Experimental Investigation Oral [Show abstract]
  • Ioannis Katsantonis, FORTH, Greece
  • Maria Manousidaki, FORTH, Greece
  • Anastasios Koulouklidis, FORTH, Greece
  • Cristina Daskalaki, FORTH, Greece
  • Ioannis Spanos, Department of Engineering Science, University of Oxford , UK
  • Constantinos Kerantzopoulos, FORTH, Greece
  • Anna Tasolamprou, Physics and Systems, Department of Physics, National and Kapodistrian University of Athens, Greece
  • Costas Soukoulis, FORTH & Department of Physics and Astronomy, Iowa State University, Greece & USA
  • Eleftherios Economou, FORTH, Greece
  • Stylianos Tzortzakis, FORTH, Greece
  • Maria Farsari, FORTH, Greece
  • Maria Kafesaki, FORTH, Greece
We propose and study theoretically and experimentally a chiral metamaterial structure composed of pairs of vertical U-shape resonators of “twisted” arms. We demonstrate that the structure exhibits a large, broadband and pure optical activity in the low THz range. The experimental data indicate a polarization rotation of up to 25ο over an unmatched bandwidth of 80% (band-width/mid-frequency %). We analyze the enhanced chiral response of the structure using an equivalent RLC circuit model, which can also provide simple optimization rules for the structure response. The proposed chiral structure is easily fabricatable using direct laser writing and electroless metal plating, making it promising candidate for THz polarization control applications.
12:00 - 12:30 - Chirality In Photonic Nanostructures Across Different Length Scales Invited oral [Show abstract]
  • Carsten Rockstuhl, Karlsruhe Institute of Technology, Germany
  • Lukas Rebholz, Karlsruhe Institute of Technology, Germany
  • Benedikt Zerulla, Karlsruhe Institute of Technology, Germany
  • Mitchell Whittam, Karlsruhe Institute of Technology, Germany
  • Maxim Vavilin, Karlsruhe Institute of Technology, Germany
  • Niels Gieseler, Karlsruhe Institute of Technology, Germany
  • Dominik Beutel, Karlsruhe Institute of Technology, Germany
  • Christof Holzer, Karlsruhe Institute of Technology, Germany
  • Markus Nyman, Karlsruhe Institute of Technology, Germany
  • Marjan Krstic, Karlsruhe Institute of Technology, Germany
  • Ivan Fernandez-Corbaton, Karlsruhe Institute of Technology, Germany
<p> We study, from first principles, the linear and nonlinear optical properties of photonic systems made from chiral materials that are suitably structured. A multi-scale modeling technique is used to understand the impact of chirality on different length scales and explore the functionality of selected devices.</p>
12:30 - 14:00 - Lunch Break (Monday)
14:00 - 15:30 - Oral Sessions (Monday Afternoon 1)
14:00 - Space-time crystals

Session chairperson(s): Nikolay Zheludev; Evgeniy Narimanov

14:00 - 14:30 - Optical Nonreciprocal Forces, Ergodicity and Entropy in Metamaterial Time Crystals Invited oral [Show abstract]
  • Nikolay I. Zheludev, University of Southampton, United Kingdom
  • Venugopal Raskatla, University of Southampton, United Kingdom
  • Tongjun Liu, University of Southampton, United Kingdom
  • Jinxiang Li , Nanyang Technological University, Singapore
  • Kevin F. MacDonald, University of Southampton, United Kingdom
In a remarkable similarity with nonreciprocal nonequilibrium process in nature, nonreciprocal forces of light can underpin breaking of time translation symmetry and ergodicity, and exert control over entropy in a nanowire metamaterial
14:30 - 14:45 - Photon Squeezing in Photonic Time Crystals Oral [Show abstract]
  • Jaime Echave-Sustaeta, Universidad Autónoma de Madrid, Condensed Matter Physics Center (IFIMAC), Spain
  • Francisco José García-Vidal, Universidad Autónoma de Madrid, Condensed Matter Physics Center (IFIMAC), Spain
  • Paloma Arroyo-Huidobro, Universidad Autónoma de Madrid, Condensed Matter Physics Center (IFIMAC), Spain
We follow a transfer matrix approach and study the connection between the classical reflectivity of a photonic time crystal and the probability of creating photon pairs; we prove how the former completely determines the latter. Furthermore, we describe momentum bandgaps and complex Floquet frequencies within a unitary framework.
14:45 - 15:00 - Particle-hole Instabilities In Photonic Time-varying Crystals Oral [Show abstract]
  • João Câmara Serra, Instituto de Telecomunicações, Universidade de Lisboa - Instituto Superior Técnico, Portugal
  • Emanuele Galiffi, City University of New York, Advanced Science Research Center, USA
  • Paloma Huidobro, Universidad Autonoma de Madrid, Spain
  • John Pendry, Imperial College London, UK
  • Mário Silveirinha, Instituto de Telecomunicações, Universidade de Lisboa - Instituto Superior Técnico, Portugal
We discuss how the modal coupling arising from time-varying modulations combined with the particle-hole symmetry of photonic systems leads to resonant interactions of positive and negative frequency oscillators. In particular, we show that the interplay between material dispersion and spacetime modulations may induce parametric instabilities for arbitrarily small modulation speeds, in the absence of dissipative mechanisms.
15:00 - 15:15 - The Path to Photonic Time Crystal: Ultrafast Optical Modulation by Virtual Interband Transitions. Oral [Show abstract]
  • Evgeniy Narimanov, Purdue University, USA
A new frontier in optics research has been opened by the recent developments in non-perturbative optical modulation in both time and space that creates temporal boundaries generating “time- reflection” and “time-refraction” of light in the medium, leading to the creation of a Photonic Time Crystal. However, the formation of temporal boundaries for light relies on optical modulation of the refractive index that at the same time is both strong and fast even on the time scale of a single optical cycle – leading to conflicting requirements for all existing methods of optical modulation. In this work we introduce the solution to this seemingly insurmountable problem, that is based on virtual interband transition excitation. Being fundamentally dissipation-free, optical modulation by virtual excitation does not face the problem of heat accumulation and dissipation in the material, while the transient nature of the excited virtual population that modifies the material response only on the time scale of a single optical cycle, ensures that the resulting change in the refractive index is inherently ultrafast. We furthermore demonstrate that the proposed approach can be readily implemented using already existing optical materials and technology.
15:15 - 15:30 - Scattering at Space-Time Engineered-Modulation (STEM) Wedges Oral [Show abstract]
  • Amir Bahrami, KU Leuven, Belgium
  • Christophe Caloz, KU Leuven, Belgium
We introduce the concept of a space-time wedge. We provide a closed-form solution for the electromagnetic scattering occurring in such a structure and describe the corresponding physics, which includes multiple space-time scattering and related cascade Doppler shifting.
14:00 - Elastic metamaterials I

Session chairperson(s): Benjamin Vial; Ricardo Martin Abraham-Ekeroth

14:00 - 14:30 - Numerical Studies on Single and Coupled Bound States in the Continuum within Elastic-Wave Metamaterial Mesostructures Invited oral [Show abstract]
  • Daniel Torrent Martí, Universitat Jaume I, Spain
  • Ricardo Martín Abraham-Ekeroth , Universitat Jaume I , Spain
  • Liangshu He, Universitat Jaume I, Spain
  • Gao Nan, Universitat Jaume I , Spain
Bound states in the Continuum (BICs), which appear in the spectra of various wave fields, are now recognized as powerful tools to enhance field-matter interactions and apply them to sensors, waveguides, and emitters, with the main focus on the design of small- scale devices to improve the performance of information processors. Moreover, their construction typically relies on straightforward strategies, such as the perturbative modification of the geometry and composition of structures. These bound states allow for full control between evanescent and radiative states, wide bandgap tunability, and switching between single or collective resonance phenomena. While their unique resonance properties, such as large quality factors and high sensitivity to perturbative changes, make them stand out, a comprehensive understanding of an appropriate design approach and how they can couple with radiative states is still lacking. These challenges become more pronounced within the framework of elastic-wave propagation, where the polarization conversion and anisotropy of the structures complicate the understanding and prediction of bound states.
14:30 - 15:00 - Modal Analysis for Controlling Elastic Waves in Platonic Metamaterials Invited oral [Show abstract]
  • Benjamin Vial, Imperial College London, United Kingdom
  • Marc Martı́ Sabaté, Imperial College London, United Kingdom
  • Sébastien Guenneau, Imperial College London, United Kingdom
  • Richard Craster, Imperial College London, United Kingdom
We present our recent work on structured arrays and clusters of scatterers in elasticity to design elastic platonic metamaterials that utilise resonant phenomena. Numerical simulations based on a Green's function approach allows us to solve for the multiple scattering problem for resonators atop a thin elastic plate and to find eigenmodes of those open structures, the so-called quasi-normal modes. We derive a modal expansion of the displacement field that gives a valuable insight on the resonant interaction of external forces with the system's eigenmodes and that provides a reduced-order model capable of efficiently computing physical quantities of interest such as the local density of states. Potential applications of the elastic devices include elastic delay lines and passive energy harvesters.
Media link(s):

Check out the open-source code used in this work at https://gitlab.com/benvial/klove

15:00 - 15:15 - Design to acoustics by applying vibroacoustic metamaterials to a vehicle front axle carrier frame Oral [Show abstract]
  • Nikolai Kleinfeller, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Sebastian Rieß, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Heiko Atzrodt, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Armin Weber, RWTH Aachen University, Institute for Automovtive Engineering, Germany
  • José Cóndor López, Mercedes-Benz AG, NVH Powertrain Integration CAE, Germany
  • Karsten Finger, Mercedes-Benz AG, NVH Powertrain Integration CAE, Germany
A vibroacoustic metamaterial is applied to the cross bridge component of a vehicle front axle carrier frame of an electric drive train. First, the disturbing frequency is identified by a finite element analysis and second a matching VAMM is designed. The developed prototype is manufactured using 3D-printing and the resonators are tuned and investigated via experiments.
15:15 - 15:30 - Tuning the Response of Bubble-based Metamaterials with Short Transient Pulses Oral [Show abstract]
  • Vicky Kyrimi, National and Kapodistrian University of Athens, Greece
Bubble-based metamaterials have been extensively studied both theoretically and experimentally thanks to their simple geometry and their ability to manipulate acoustic waves. The present numerical study focuses on the changes induced to the response of a bubbly meta-screen, subject to different excitation pulses. For complex frequency excitation the bubbles delay to return to their equilibrium position for a couple of moments, hence the energy is stored in the system during those moments. This research provides a new strategy to actively control the response of a bubbly meta-screen and seeks to inspire future studies towards further optimization of the incident pulse based on the functionalities in need.
14:00 - Wave propagation and dispersion modeling in metastructures

Session chairperson(s): Oscar Quevedo-Teruel; Mariana Dalarsson

14:00 - 14:30 - Glide Symmetries and their effect in the anisotropy and impedance matching Invited oral [Show abstract]
  • Oscar Quevedo-Teruel, KTH Royal Institute of Technology, Sweden
It has been widely reported that the use of glide symmetries can provide beneficial effects in the electromagnetic response of periodic structures. Two of the most reported features are their ability to increase the bandwidth and attenuation of holey structures in parallel plate configurations; as well as the ability to increase generally the isotropy and effective refractive index of periodic structures. However, there are other features that did not get as much attention in the literature, and they will be the main goal of this presentation. In particular, we will discuss the potential use of glide symmetries to enhance the anisotropy of periodic structures and to improve the impedance matching.
14:30 - 15:00 - Exploring Dispersion Characteristics of a Glide-Symmetric Square Patch Metamaterial Extended oral [Show abstract]
  • Jim A. Enriquez, ITMO University, Russia
  • Juan D. Baena, National University of Colombia, Colombia
  • Pavel A. Belov, ITMO University, Russia
This work investigates the dispersion characteristics of an anisotropic metamaterial composed of glide-symmetric metal square patches in a vacuum background. We present theoretical formulas for calculating the metamaterial's electromagnetic properties. The validity of the model is confirmed by comparing band diagrams and isofrequency contours obtained from theory and simulations.
15:00 - 15:15 - TE-waves in a Hollow Waveguide Filled With a Periodic Graded Dielectric Medium Oral [Show abstract]
  • Balwan Rana, KTH Royal Institute of Technology, Sweden
  • Mariana Dalarsson, KTH Royal Institute of Technology, Sweden
A theoretical study of TE-wave propagation in a hollow circular waveguide with a graded dielectric medium is presented. The medium is modeled using a squared cosine function that oscillates between two unique complex dielectric media to simulate a periodic multilayer structure. The proposed model is applicable to arbitrary complex permittivities of the two media, including negative values for chiral metamaterials. The exact analytical result for the longitudinal magnetic field component Hz is obtained, while the transverse electric and magnetic field components could be determined using the appropriate Maxwell’s equations.
15:15 - 15:30 - Asymmetric properties of Babinet complementary metamaterial multilayers Oral [Show abstract]
  • Emese Tóth, University of Szeged, Department of Optics and Quantum Electronics, Hungary
  • Olivér Fekete, University of Szeged, Department of Optics and Quantum Electronics, Hungary
  • Balázs Bánhelyi, University of Szeged, Department of Computational Optimization, Hungary
  • Mária Csete, University of Szeged, Department of Optics and Quantum Electronics, Hungary
Spectral regions of asymmetric transmission and polarization rotation were determined on a highly reflective and moderately chiral metamaterial constructed with convex-concave-convex Babinet complementary patterns. By optimizing the orientation of the composing nanocrescents surrounding the central nanorings in the two sets of analogous convex-concave patterns forming a wavelength-scaled cavity, enhanced asymmetric transmission and chirality as well as large generalized Faraday rotation was achieved without any external bias.
14:00 - Dynamics of nonlinear metaoptics

Session chairperson(s): Anatoly Zayats; JACOB KHURGIN

14:00 - 14:30 - Ultrafast Nonlinearity and Time-dependent Quadratic Nonlinear Response in Ultrathin Hetero-nanostructures Invited oral [Show abstract]
  • Anatoly Zayats, King's College London, United Kingdom
  • Anton Bykov, King's College London, United Kingdom
Ultrafast nonlinearity is a basis for the development of time-varying media, in particular those operating in the epsilon-near-zero regime. Here, we will discuss how to control the time response of a free-electron nonlinearity and demonstrate two orders of magnitude stronger modulation of the second-harmonic generation than the linear optical properties.
14:30 - 14:45 - Dynamics of Second-Harmonic Generation in Bilayer Nonlinear Metamaterials Oral [Show abstract]
  • Danielle Ben-Haim, Tel-Aviv University, Israel
  • Tal Ellenbogen, Tel-Aviv University, Israel
We study the dynamics of second-harmonic generation from a nonlinear metamaterial composed ‎of two layers of plasmonic nanoparticle array with a geometric phase difference, that allows ‎control of the second-harmonic scattering and also reveals a confined dark mode, as a foundation ‎for designing efficient and tunable multilayered nonlinear metamaterials.‎
14:45 - 15:00 - Intrinsic Nonlinear Geometric Phase Driven By Nonlinear Tensor Rotations In Second-Harmonic Generation Processes Oral [Show abstract]
  • Luca Carletti, Department of Information Engineering, University of Brescia, Italy
  • Davide Rocco, Department of Information Engineering, University of Brescia, Italy
  • Maria Antonietta Vincenti, Department of Information Engineering, University of Brescia, Italy
  • Domenico de Ceglia, Department of Information Engineering, University of Brescia, Italy
  • Costantino de Angelis, Department of Information Engineering, University of Brescia, Italy
We reveal the intrinsic nonlinear geometric phase in AlGaAs film and metasurfaces' SHG, distinct from prior findings in nonlinear dielectric, plasmonic, or hybrid metasurfaces. This phenomenon, hinged on nonlinear tensor anisotropy, allows novel phase manipulation, broadening nonlinear wavefront shaping metasurfaces' potential with distinct effects.
15:00 - 15:30 - Nonperturbative Regime in Optical Nonlinearities, Large and small, fast and slow Invited oral [Show abstract]
  • JACOB KHURGIN, Johns Hopkins University, USA
  • Nathaniel Kinsey, Virginia Commonwealth University, USA
A unified theory for nonlinear index behavior beyond the perturbative limit is developed, applicable to both ultrafast nonlinearities in transparent materials and slower nonlinearities in absorbing materials like transparent conductive oxides. Each material is characterized by a single saturation parameter rooted in its physical properties.
14:00 - Enhancing light-matter interactions

Session chairperson(s): Elefterios Lidorikis; PAVEL GINZBURG

14:00 - 14:30 - Enhanced Light-Matter Interactions in Graphene-based Plasmophotonic and Optoelectronic Devices for Applications in Infrared Light Sensing and Modulation Invited oral [Show abstract]
  • Elefterios Lidorikis, University of Ioannina, Greece
A self-consistent modelling framework for graphene light-matter interactions is presented, including hot carrier thermalization, relaxation, and saturation. Accurate description and design of graphene-based applications, enhanced by plasmonic and photonic resonators, are demonstrated, such as light-sensing and modulation in the infrared range. Extensive comparisons against experiments provide firm validation of methods.
14:30 - 14:45 - Inverse Design of Polariton Devices using metamaterial-based cavities Oral [Show abstract]
  • Oliver Kuster, Karlsruhe Institute of Technology, Germany
  • Yannick Augenstein, Karlsruhe Institute of Technology, Germany
  • Thomas Sturges, Karlsruhe Institute of Technology, Germany
  • Carsten Rockstuhl, Karlsruhe Institute of Technology, Germany
Polaritonics has shown to be a promising candidate for optoelectronic devices. Recent advances in polaritonics allow us to generate polariton condensates at room temperature using organic semiconductors. In addition, improved fabrication methods allow us to manipulate the effective potential the polariton condensate experiences at even smaller scales. These tailored potentials resemble metamaterials but for polariton condensates. Using gradient-based optimization, we can implement a free-form optimization of the effective potential to design polaritonic devices with desired functionality.
14:45 - 15:00 - Valley Purcell effect for Two-dimensional Dirac Materials Oral [Show abstract]
  • SeokJae Yoo, Inha University, Korea (South)
  • KiJeong Park, Inha University, Korea (South)
  • SeungWoo Choi, Inha University, Korea (South)
Graphene, transition metal dichalcogenides (TMDs), and hexagonal boron nitrides (hBNs) are typical one-atom-thick two-dimensional (2D) Dirac materials, whose electronic behaviors are described by the Dirac equation rather than the ordinary Schrodinger equation. Valleys, local extrema in the electronic band structures, are one of the intriguing properties of such 2D Dirac materials. Valley degree of freedom plays the role of information carrier, promising novel optoelectronic applications. We present a theory of the valley Purcell effect, explaining the optical cavity-driven modification of the valley-selective exciton recombination. Design consideration for optical cavities of the high valley Purcell factor is also provided.
15:00 - 15:15 - Optically Responsive Metamaterial Drug Delivery Capsules Oral [Show abstract]
  • PAVEL GINZBURG, Tel Aviv University, Israel
  • Hani Barhom, Tel Aviv University, Israel
  • Andrey Machnev, Tel Aviv University, Israel
  • Andrey Ushkov, Tel Aviv University, Israel
  • Denis Kolchanov, Tel Aviv University, Israel
  • Pavel Bezrukov, Tel Aviv University, Israel
Inorganic nanoparticles with their capacity to accommodate multiple biomedical modalities, are among the candidates for realizing light-responsive theranostic carriers. Revealing the mechanisms of cargo-fluid and cargo-cell interactions in vitro, and fine-tuning the parameters of light-driven processes, offers a significant advantage in customizing applications for in vivo environments. In this contribution, we will explore the concept of a metamaterial drug delivery capsule, golden and gilded vaterite, and demonstrate its unambiguous advantages in the future paradigm of light-driven theranostics. Optomechanical drug delivery, label-free bioimaging, drug release, and optothermal therapy with the aid of metamaterial nanoparticles will be shown.
15:15 - 15:30 - Probing Mie-resonant nanoparticles with swift electron beams Oral [Show abstract]
  • Christos Tserkezis, University of Southern Denmark, Denmark
  • P. Elli Stamatopoulou, Karlsruhe Institute of Technology, Germany
  • Christian Wolff, University of Southern Denmark, Denmark
  • N. Asger Mortensen, University of Southern Denmark, Denmark
We discuss the richness of information that one can extract about the optical response of Mie-resonant high-index dielectric nanoparticles, when excited by a swift electron beam, in electron-energy loss or cathodoluminescence spectroscopy measurements. In particular, we analyse how, apart from Mie modes of electric or magnetic multipolar type, electron beams passing nearby or through the particle can produce a diversity of resonant or interference spectral features, due to the interaction of Mie modes with transition or Cherenkov radiation, or with intrinsic material processes such as interband transitions. We thus highlight the importance of precise analytic or semi-analytic theoretical approaches for the interpretation of measured or simulated spectra.
15:30 - 16:00 - Coffee Break (Monday Afternoon)
16:00 - 17:30 - Oral Sessions (Monday Afternoon 2)
16:00 - Switched and time-modulated metamaterials

Session chairperson(s): Carlo Rizza; Luca Stefanini

16:00 - 16:30 - Excitation of Natural Resonances in Time-Varying Dispersive Interfaces Invited oral [Show abstract]
  • Carlo Rizza, Department of Physical and Chemical Science, University of L' Aquila, Italy
  • Maria Antonietta Vincenti , Department of Information Engineering, University of Brescia, Italy
  • Alessandra Contestabile, Department of Physical and Chemical Science, University of L' Aquila, Italy
  • Giuseppe Castaldi , University of Sannio, Department of Engineering, Fields & Waves Lab, Italy
  • Vincenzo Galdi , University of Sannio, Department of Engineering, Fields & Waves Lab, Italy
  • Michael Scalora, Aviation and Missile Center, U.S. Army CCDC, Redstone Arsenal,, Italy
Generally, natural resonances are excited in a linear time-invariant system when the incident field spectrum matches the system's natural frequencies. Here, we suggest a new scheme for the excitation of resonant modes supported by a metasurface. The effect is activated by a temporal boundary, i.e., an abrupt change in the electromagnetic parameters of the time-varying metasurface. As a leading example, we explore wave scattering from a time-varying interface characterized by a resonant Lorentz dispersion with a step-like temporal variation in its parameters. Remarkably, this phenomenon enables the coupling of propagating waves to evanescent ones, allowing the direct far-field excitation of surface-wave modes without the necessity for spatial structuring or prolonged temporal modulations.
16:30 - 16:45 - Temporal Interfaces in Time-modulated Metasurface for the excitation of Space-Time Wave Packet Oral [Show abstract]
  • Luca Stefanini, Università degli studi di Roma Tre, Italy
  • Davide Ramaccia, Università degli studi di Roma Tre, Italy
  • Alessio Monti, Università degli studi di Roma Tre, Italy
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Stefano Vellucci, Università degli studi di Roma Tre, Italy
  • Mohsen Karamirad, Università degli studi di Roma Tre, Italy
  • Michela Longhi, Niccolò Cusano University, Italy
  • Alessandro Toscano, Università degli studi di Roma Tre, Italy
  • Andrea Alù, Photonics Initiative, Advanced Science Research Center, USA
  • Vincenzo Galdi, University of Sannio, Italy
  • Filiberto Bilotti, Università degli studi di Roma Tre, Italy
Space-time wave packets (STWPs) are a class of polychromatic field configurations that do not experience diffraction as they propagate. This property is given by their peculiar spatial-temporal light structure that satisfies a one-to-one correlation between spatial and temporal frequencies, making their excitation constrained to the use of complex launchers. To overcome these challenges in excitation, in this contribution, we exploit the temporal scattering properties of a surface wave propagating along a metasurface that abruptly switches its surface impedance. We demonstrate that the surface wave couples with free-space radiation as a nondiffracting field satisfying the properties of a space-time wave packet. Analytical formulation and numerical simulations are provided to verify the STWP-like propagation.
16:45 - 17:00 - SAR Deceptive Jamming Method Based on Phase gradient Modulation Oral [Show abstract]
  • Junjie Hou, Central China Normal University, China
  • Hai Lin, Central China Normal University, China
Time-varying metasurface has attracted extensive attention in recent years because of its modulation ability to wireless communication signals. In principle, phase modulation alters the interpulse characteristics of the original signal and fundamentally interferes with the processing of the radar signal. In this article, a synthetic aperture radar (SAR) camouflage approach is presented by modulating the phase of reflection radar signal based on the phase gradient modulation. The intrapulse phase modulation is applied to alter the target position in range domain, and the interpulse phase modulation is applied to alter the target position in azimuth domain. Through the derivation formula and simulation experiment, the camouflage effect under phase modulation is verified.
17:00 - 17:15 - Experimental Evidence of Absorption Beyond the Rozanov Bound and Absorber Compression via Time Modulation Oral [Show abstract]
  • Matteo Ciabattoni, Cornell University, USA
  • Francesco Monticone, Cornell University, USA
Recent advances in applied electromagnetics have highlighted the potential of time-varying systems to go beyond the conventional performance limits that restrict their time-invariant counterparts. An example of such a limit is the Rozanov absorption bound. In this paper, we present the design and experimental testing of a periodically modulated time-varying absorber that can outperform the Rozanov bound over a broad bandwidth, leading to strongly reduced in-band reflections. Furthermore, we show that by introducing time-modulation, the thickness of an absorber can be shrunk to half without compromising its performance.
17:15 - 17:30 - Asymmetric Scattering at Temporal Interfaces Oral [Show abstract]
  • Mohamed Hesham Mohamed Mostafa, Aalto University, Finland
  • Mohammad Sajjad Mirmoosa , University of Eastern Finland, Finland
  • Andreas Norrman, University of Eastern Finland, Finland
  • Sergei Tretyakov, Aalto University, Finland
Scattering from temporal interfaces has emerged as a forefront area of research in the field of wave manipulation. However, it has been limited to symmetric scattering with respect to propagation direction and field polarization of the incident fields. Here, we explore asymmetric temporal scattering, particularly focusing on its realization at bianisotropic temporal interfaces. Furthermore, potential applications will be addressed during the presentation.
16:00 - Metastructures for controlling sound

Session chairperson(s): Noé Jiménez; Vincent Pagneux

16:00 - 16:30 - Design strategies for amplitude and phase acoustic holograms in biomedical ultrasound Invited oral [Show abstract]
  • Noé Jiménez, Consejo Superior de Investigaciones Científicas - Universitat Politècnica de València, Spain
  • Diana Andrés, Consejo Superior de Investigaciones Científicas - Universitat Politècnica de València, Spain
  • Alba Eroles-Simó, Consejo Superior de Investigaciones Científicas - Universitat Politècnica de València, Spain
  • Victor Vegas, Consejo Superior de Investigaciones Científicas - Universitat Politècnica de València, Spain
  • Alicia Carrión, Consejo Superior de Investigaciones Científicas - Universitat Politècnica de València, Spain
  • Jose L. Alonso-Ramos, Consejo Superior de Investigaciones Científicas - Universitat Politècnica de València, Spain
  • Juan J. Rodriguez-García, Consejo Superior de Investigaciones Científicas - Universitat Politècnica de València, Spain
  • Francisco Camarena, Consejo Superior de Investigaciones Científicas - Universitat Politècnica de València, Spain
We present several topologies for phase-and-amplitude acoustic holograms based on metamaterial and phononic crystals. These approaches go beyond traditional phase holograms and produce sharper acoustic images, suitable for non-invasive and localized therapeutic ultrasound applications like neuromodulation, drug delivery or surgery, or biomedical ultrasound imaging.
16:30 - 16:45 - Cascaded duct unit cell capable of independent phase and group delay control for broadband acoustic metalenses Oral [Show abstract]
  • Dingcheng Yang, UNSW Canberra at the Australian Defence Force Academy, Australia
  • Yankei Chiang, UNSW Canberra at the Australian Defence Force Academy, Australia
  • David Powell, UNSW Canberra at the Australian Defence Force Academy, Australia
This paper presents a cascaded duct unit cell design that can manipulate the phase and group delay at the same time. The cell is of three-quarters wavelength thickness to ensure the narrow duct is in resonance where the largest group delay can be acquired. Controlling the width of the narrow duct can adjust the impedance mismatch and further tune the group delay. The phase is tuned via the wide duct which is equivalent to the simple waveguide. Thanks to the straightforward geometry, the phase and group delay can be expressed explicitly by simple equations. A metalens consisting of cascaded cells demonstrates good consistency in focal spot position as well as a higher energy amplifying factor at the focal spot in the frequency range of 2.5 kHz to 3.5 kHz.
16:45 - 17:00 - Wide field-of-hearing metalens for wide-angle acoustic focusing Oral [Show abstract]
  • Beomseok Oh, Pohang University of Science and Technology (POSTECH), Korea (South)
  • Dongwoo Lee, Pohang University of Science and Technology (POSTECH), Korea (South)
  • Junsuk Rho, Pohang University of Science and Technology (POSTECH), Korea (South)
<p> Metalenses are innovative devices that manipulate waves and have shown impressive abilities so far. However, a challenge arises from the limitations in angular response caused by off axis aberrations, which diminish the focusing capability. In this work, we propose a blueprint by introducing the concept of a wide field of hearing (FOH) metalens, to capture and focus acoustic waves with reduced aberrations. We utilize a planar thin metalens that exploits perfect acoustic symmetry conversion. Through experimental validation, we achieve a robust wide FOH capability of around 140 degrees.</p>
17:00 - 17:15 - Towards Optimal Spatiotemporal Wavefront Shaping for the Cocktail Party Problem with Inverse Design of an Acoustic Reconfigurable Metasurface in Disordered Media Oral [Show abstract]
  • Raphael Pestourie, Georgia Institute of Technology, USA
  • Constant Bourdeloux, Institut Langevin, ESPCI Paris, Université PSL, France
  • Fabrice Lemoult, Institut Langevin, ESPCI Paris, Université PSL, France
  • Mathias Fink, Institut Langevin, ESPCI Paris, Université PSL, France
  • Steven G. Johnson, Massachusetts Institute of Technology, USA
Multiple-user multiple-input multiple-output applications have recently gained a lot of attention. Here, we show an efficient optimization formulation for the design of all the temporal and spatial degrees of freedom of an acoustic reconfigurable metasurface for the cocktail party problem. In the frequency domain, the closed-form least square solution matches the optimal time reversal solution for multiple emitter-receiver pairs, optimizing for each frequency independently. This is more efficient than solving in the time domain where the time convolution mixes all the degrees of freedom into a resource-intensive optimization. We illustrate this methodology by optimizing the frequency response of a design for two pairs of emitters-receivers using the Green's functions of disordered media that are measured experimentally. We report strong performance that will be put in perspective in future work, where we will analyze the robustness of the design to noise in the data and design the convolutional filters that match the optimal frequency response for experiment validation of the design.
17:15 - 17:30 - Artificial Neural Networks-based On-demand Inverse Design For 3D Chiral Metamaterials Oral [Show abstract]
  • Jehyeon Shin, POSTECH, Korea (South)
  • Jeonghoon Park, POSTECH, Korea (South)
  • Jaebum Noh, POSTECH, Korea (South)
  • Junsuk Rho, POSTECH, Korea (South)
The bandgap properties of chiral metamaterials can be used to inhibit wave modes in physical beams. We use the inverse neural network to get chiral structures that have bandgap requirements by adjusting the range of maximal stress. This approach allows for building metamaterials while adjusting physical characteristics as intended.
16:00 - Analytical and numerical modeling of RF metastructures

Session chairperson(s): David Smith; Stefano Vellucci

16:00 - 16:30 - Establishing the Equivalence of Circuit and Polarizability Models for Slot-Like Waveguide-Fed Metamaterial Elements No show [Show abstract]
  • David Smith, Duke University, USA
  • Insang Yoo, Yonsei University, Korea
  • Mohsen Sazegar, Kymeta Corporation, USA
We detail a method of assigning equivalent lumped circuit parameters to metamaterial elements and show that the circuit model can be readily transformed to a polarizability model.
16:30 - 16:45 - A Numerical Approach On The Verification Of Parameter Retrieval Techniques For Composite Periodic Electromagnetic Media Oral [Show abstract]
  • Michalis Nitas, Department of Space Research and Technology, Technical University of Denmark, Bld. 348, Ørsteds Plads, 2800 Kgs. Lyngby, Denmark, Denmark
  • Maria Kafesaki, Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (FORTH-IESL), GR-70013 Heraklion, Crete, Greece, Greece
  • Samel Arslanagic, Department of Space Research and Technology, Technical University of Denmark, Bld. 348, Ørsteds Plads, 2800 Kgs. Lyngby, Denmark, Denmark
A new technique is proposed for the confirmation of the accuracy of effective parameter retrieval techniques for composite periodic electromagnetic media. The retrieved effective parameters are inserted into the analytical relations of wave propagation in a complex homogeneous medium and a reconstructed dispersion diagram is formed. This diagram is then compared to the original dispersion diagram returned by the eigenvalue analysis of the composite inhomogeneous structure and the discrepancies between them are determined.
16:45 - 17:00 - Super Cavity Mode In Volumetric Resonators: A Comparative Analysis Of A Dielectric Resonator And An Array Of Split-ring Resonators Oral [Show abstract]
  • Viktor Puchnin, ITMO University, Russia
  • Sergey Geyman, ITMO University, Russia
  • Alexey Slobozhanyuk, ITMO University, Russia
  • Mikhail Rybin, ITMO University, Russia
  • Alena Shchelokova, ITMO University, Russia
Quasi-bound states in the continuum are fascinating phenomena due to the interaction of the resonant modes, which allows for a high-Q factor. Here, we propose an array of split-ring resonators to achieve a similar interaction. The resonator design replicates Fabry-Perot and Mie-like modes, in which interference produces the quasi-BIC-related mode.
17:00 - 17:15 - Constraints and Loss Effects of Babinet Metasurfaces Oral [Show abstract]
  • Alexander Zhuravlev, School of Physics and Engineering, ITMO University, St. Petersburg, Russia, Russia
  • Stanislav Glybovski, School of Physics and Engineering, ITMO University, St. Petersburg, Russia, Russia
  • Andrey Sayanskiy, School of Physics and Engineering, ITMO University, St. Petersburg, Russia, Russia
  • Irina Melchakova, School of Physics and Engineering, ITMO University, St. Petersburg, Russia, Russia
  • Juan Baena, Physics Department, Universidad Nacional de Colombia, Bogota, Colombia, Colombia
A study of constrains for reflection coefficients from lossy metasurfaces is presented. Reflection coefficients have been found to describe circumference paths on the complex plane whose centers and radius are affected by losses. We have systematically observed that the effect of losses on a metasurface made of strip resonators is weaker than for the complementary metasurface made of slot resonators.
17:15 - 17:30 - Pure Moving Optical Media by Magnetochiral Metasurfaces Oral [Show abstract]
  • SATOSHI TOMITA, Tohoku University, Japan
  • Toshiyuki Kodama, Tohoku University, Japan
  • Kei Sawada, RIKEN SPring-8 Center, Japan
  • Toshihiro Nakanishi, Kyoto University, Japan
We demonstrate numerical calculation of microwave bianisotropy by magnetochiral (MCh) metasurfaces consisting of double Z-type gammadions with perpendicularly magnetized substrate. By combining the ordinary MCh metasurfaces with the contraposition ones, effective polarizability tensors exhibit only non-reciprocal moving-type bianisotropy. Achieved perfect transmission with phase difference of $pi$ realizes an ideal gyrator for arbitrary spatial and polarization modes.
16:00 - Periodic structures

Session chairperson(s): Yarden Mazor; Adam Overvig

16:00 - 16:30 - Metasurface Design with Nontrivial Slots and Knotted Wire Unit Cells Invited oral [Show abstract]
  • Yarden Mazor, Tel-Aviv University, Israel
  • Nadav Goshen, Tel-Aviv University, israel
The design of metasurfaces and frequency-selective surfaces is usually based on unit cells composed of metal strips, or slots, in rectangular geometries. These have many advantages - they are easy to fabricate, and simple circuit models can be applied to predict their frequency response. However, current simulation and fabrication techniques allow us to exploit a broader range of geometries. In this talk, we will look into the applications of two types of more complex unit cells. First, we will demonstrate our nearly 90-degree angularly stable design based on a smoothly varying 'cloverleaf' slot. We will apply a spatially dispersive surface impedance model to elucidate the response's angular dependence. Next, we will show the interesting phenomena and applications that arise when constructing a metasurface from knotted wires. Knotted wires have already been shown to have unique scattering and radiation properties. When arranging these into a 2D knotted metasurface and carefully adjusting the knot features, one can achieve various electromagnetic wavefront manipulations, ranging from near-optimal polarization rotation to anomalous refraction. We will map the behavior of different metasurfaces based on the knot parameters and examine possible ways to make these easier to fabricate.
16:30 - 17:00 - Nonlocal Metasurfaces for Spatially Structuring Bound and Quasi-Bound States Invited oral [Show abstract]
  • Adam Overvig, Stevens Institute of Technology, USA
We report on carefully designed nonlocal metasurfaces supporting spatially structured eigenstates embedded in the continuum, with diverging Q-factor when excited by custom wavefronts. This extends the physics of bound states in the continuum in flat optics beyond plane waves.
17:00 - 17:15 - Glide Symmetric Double Corrugated Groove Gap Waveguides Oral [Show abstract]
  • Nelson Castro Salas, Universidad Carlos III de Madrid, Spain
  • Miguel Saavedra-Melo, Dpt. Electrical Engineering and Computer Science, University of California, Irvine, United States of America
  • Filippo Capolino, Dpt. Electrical Engineering and Computer Science, University of California, Irvine, United States of America
  • Eva Rajo-Iglesias, Universidad Carlos III de Madrid, Spain
The dispersion properties of electromagnetic modes in glide-symmetric double cor- rugated waveguides are explored in this work. Two different configurations are considered, one of them has application in traveling wave tube amplifiers, and the second one offers a degenerate band edge feature (a specific kind of exceptional point) with potential applications to design oscillators and leaky wave antennas
17:15 - 17:30 - Design of laser-driven integrated optics extended interaction structures for particle acceleration Oral [Show abstract]
  • Roberta Palmeri, DIIES, University Mediterranea of Reggio Calabria, Italy, Italy
  • Giorgio S. Mauro, LNS, National Institute for Nuclear Physics, Italy
  • Alberto Bacci, INFN-Milano, National Institute for Nuclear Physics, Italy
  • Andrea Locatelli, Department of Information Engineering, University of Brescia, Italy
  • Luca Vincetti, Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Italy
  • Santi C. Pavone, Department of Electrical, Electronics, and Computer Engineering, University of Catania, Italy
  • Nunzio Salerno, Department of Electrical, Electronics, and Computer Engineering, University of Catania, Italy
  • Carmelo F. Fiore, Department of Electrical, Electronics, and Computer Engineering, University of Catania, Italy
  • Davide Guarnera, DIIES, University Mediterranea of Reggio Calabria, Italy, Italy
  • Giuseppe Torrisi, LNS, National Institute for Nuclear Physics, Italy
  • Gino Sorbello, Department of Electrical, Electronics, and Computer Engineering, University of Catania, Italy
We provide an overview of our research concerning Physics-Based (PB) and Inverse-Design (ID) methodologies in the development of co-linear adiabatically-tapered synchronous integrated optics structures for particle acceleration. Extended interaction structures, wherein the laser electromagnetic-field guided mode and particles propagate in the same direction, offer superior scalability and performance compared to configurations with transverse illumination. We demonstrate that PB and ID methodologies are versatile for both relativistic and non-relativistic accelerating particles, with ID showing a promising potential for transverse focusing.
16:00 - Quantum and superconducting metamaterials

Session chairperson(s): Sergey Bozhevolnyi; Cesare Soci

16:00 - 16:30 - Nanophotonic strategies for integrated superconducting nanowire single photon detectors Invited oral [Show abstract]
  • Filippo Martinelli, Nanyang Technological University, Singapore
  • Pierre Brosseau, Nanyang Technological University, Singapore
  • Shuyu Dong, Nanyang Technological University, Singapore
  • Anton Vetlugin, Nanyang Technological University, Singapore
  • Mariia Sidorova, Nanyang Technological University, Singapore
  • Giorgio Adamo, Nanyang Technological University, Singapore
  • Cesare Soci, Nanyang Technological University, Singapore
We implement nanophotonic strategies to tackle current issues in superconducting nanowire single photon detector (SNSPD) technologies, namely the use of BIC waveguides for SNSPD heterointegration in planar photonic circuits, distributed coherent absorption for photon number resolution, and metamaterials approaches for polarization control and quantum-state tomography.
16:30 - 16:45 - Nonlinear Space-Time Metamaterials: Conceptual Distinctions, Dispersion Analysis, Experimental Implementation, and Practical Applications Oral [Show abstract]
  • Sajjad Taravati, University of Southampton, United Kingdom
This study presents an in-depth analysis of nonlinear space-time metamaterials, focusing on their theoretical foundation, dispersion properties, experimental realization, and applications in cutting-edge telecommunication and quantum technologies. By contrasting these materials with their linear counterparts, we underscore the pivotal role of nonlinearity and space-time modulation in shaping their unique dispersion characteristics. Nonlinear space-time metamaterials, exemplified by systems incorporating space-time-varying Josephson junctions, exhibit complex dispersion behaviors attributable to their non-linear current-voltage relationships and quantum mechanical dynamics.
16:45 - 17:00 - Chiral Bound States Phenomena In Projected Bands Of The Bose-Hubbard Model Oral [Show abstract]
  • Andrei Stepanenko, London Institute for Mathematical Sciences, Royal Institution, 21 Albemarle St, London W1S 4BS, UK, United Kingdom
  • Marco Di Liberto, Dipartimento di Fisica e Astronomia “G. Galilei” & Padua Quantum Technologies Research Center, Università degli Studi di Padova, I-35131, Padova, Italy, Italy
We explore time-reversal broken bound pairs in dimerized lattices with pi-flux and study the interplay between flux and interactions focusing on a ladder geometry. We demonstrate that two-particle bands differing in chirality are uncoupled, while a flux deviation from pi can bring hybridization between a bound band and a scattering continuum with different chirality, dramatically altering the dynamics of the system.
17:00 - 17:30 - Higher-Dimensional Structured Single-Photon Emission Invited oral [Show abstract]
  • Sergey Bozhevolnyi, Centre for Nano Optics, University of Southern Denmark, Denmark
Manipulation of single-photon emission from quantum emitters (QEs) has attracted a considerable attention in recent years due to its importance for quantum information technologies in quantum communication, computation, sensing and metrology. Here, recent progress in on-chip manipulation of the polarization, directionality and phase distribution in single-photon emission by making use of planar holographic QE-coupled metasurfaces is presented and discussed. Latest results include its extension for realizing single-photon sources with radiation channels that exhibit diverse (including vectorial with spin and orbital angular momenta) wavefronts and polarization characteristics, opening thereby a way to generating quantum structured light in high dimensions.
17:30 - 18:30 - Plenary Session II
17:30 - Plenary Session II

Session chairperson(s): Romain Fleury

17:30 - 18:30 - Programmable Metamaterials Plenary
  • Laura Na Liu, University of Stuttgart, Germany
18:30 - 21:30 - Welcome Reception
10 September 2024 / Start time: 9 h 0 min
09:00 - 10:00 - Plenary Session III
09:00 - Plenary Session III

Session chairperson(s): Yakir Hadad

09:00 - 10:00 - Ultrafast Nanoplasmonics: Toward Coherent Control at the Space-Time Limit Plenary [Show abstract]
  • Tamar Seideman, Northwestern University, USA
<p> Put your abstract here</p>
10:00 - 10:30 - Coffee Break (Tuesday Morning)
10:30 - 12:30 - Oral Sessions (Tuesday Morning)
10:30 - Resonators and perfect absorption

Session chairperson(s): Arthur Yaghjian; Samel Arslanagic

10:30 - 10:45 - Lithography-Free Perfect Narrowband Absorbers Using Simple Layered Structures Oral [Show abstract]
  • Carlos Lezaun Capdevila, Public University of Navarra, Spain
  • David Navajas, Public University of Navarra, Spain
  • Iñigo Liberal, Public University of Navarra, Spain
  • Miguel Beruete, Public University of Navarra, Spain
This work explores different complex permittivity combinations for material-reflector and material-spacer-reflector configurations, achieving perfect absorption under different permittivity regimes and thicknesses. Using silicon carbide, we discuss polarization and angle dependencies, and the potential of exploiting different permittivity regimes within a device for multi-band absorption.
10:45 - 11:00 - First-Principles Nanocircuit Model Of Open Electromagnetic Resonators Oral [Show abstract]
  • Carlo Forestiere, Università di Napoli Federico II, Italy
  • Giovanni Miano, Università di Napoli Federico II, Italy
  • Andrea Alù, Photonics Initiative, Advanced Science Research Center, City University of New York, U.S.A.
We derive from first principles a general circuit model representation for open, frequency dispersive electromagnetic resonators in the full-wave regime. This model extends the concepts of input and radiation impedance to the polarization current density modes induced in open resonators by an arbitrary external excitation.
11:00 - 11:30 - Fundamentals of Bandwidth and Quality Factor Invited oral [Show abstract]
  • Arthur Yaghjian, Electromagnetics Research, USA
After briefly tracing the history of quality factor, the Qz bandwidth formula and the conventional formulas for Q are derived along with the necessary and sufficient criteria for these quality factors to accurately determine the bandwidth. It is shown that the Chu lower bounds on Q can be overcome by tuning an antenna with either Lorentzian dispersive material or a simple Lorentzian circuit.
11:30 - 12:00 - Unleashing Bandwidth: Passive Highly Dispersive Matching Network Enabling Broadband Absorbing Microwave Systems Invited oral [Show abstract]
  • Pardha Sourya Nayani, Syracuse University, USA
  • Morteza Moradi, Syracuse University, USA
  • Younes Radi, Syracuse University, USA
In numerous applications from radio to optical frequencies, there is a need to design electrically thin layers capable of perfectly absorbing the incoming electromagnetic waves. From a practical point of view, there is an ever-growing demand for thinner absorbing layers that provide higher absorption bandwidths. However, there is an upper bound on the bandwidth-to-thickness ratio of these absorbers. The thinner these absorbers get, the narrower absorption bandwidth they provide. Here, we introduce a new concept for designing ultra-thin absorbers that can go beyond this upper bound defined for conventional absorbers. It is shown that the absorbers designed based on the proposed concept can provide several-fold higher absorption bandwidth compared to the same thickness absorbers designed based on conventional approaches.
12:00 - 12:30 - Single Microwave Resonators And Surface Impedance Cavities For Enhanced Wave-Matter Interactions Invited oral [Show abstract]
  • Samel Arslanagic, Technical University of Denmark, Denmark
  • Rasmus Jacobsen, Technical University of Denmark, Denmar
Bound states in the continuum may enable platforms for extreme field localization. In here, we review our activities in this exciting area. We first show how single, open, microwave resonators may enable profound field localizations. Then, we show how cylindrical impedance surfaces can be used to form open, high-Q cavities for enhanced wave-matter interactions. Our presentation will consist of analytical, numerical, and to some extent experimental results.
10:30 - Analog computing with metamaterials

Session chairperson(s): Victor Pacheco Peña; Francesco Monticone

10:30 - 11:00 - Computing with waves: from perfect splitting to routing and mathematical operations Invited oral [Show abstract]
  • Victor Pacheco Peña, Newcastle University, United Kingdom
We will discuss our latest efforts in the field including perfect splitting of electromagnetic signals photonic valley crystals and interconnected rectangular waveguides exploiting evanescent coupling, as well as the solution of partial differential equations with waves and the potential of graphical modelling techniques to represent waves propagating within waveguide networks.
11:00 - 11:30 - Can Metamaterials Help Achieve an “Optical Advantage” in Computing? Invited oral [Show abstract]
  • Francesco Monticone, Cornell University, USA
The dream of using optics and wave physics for ultra-fast and ultra-efficient computing has reemerged several times over the past decades. In this talk, we will discuss whether, why, and how metamaterials may help in the quest to achieve a quantitative “optical advantage” in computing over electronic processors.
11:30 - 12:00 - Finding and Counting Channels with Waves Invited oral [Show abstract]
  • David Miller, Stanford University, USA
In nanophotonics and with waves generally, we must know how many channels can usefully enter or leave small structures. We can understand this number based on a tunneling escape of waves. We also show how to find the best coupled channels through arbitrary optics with self-configuring photonic integrated circuit processors.
12:00 - 12:30 - Computational Metasurfaces for Spatio-Temporal, Reconfigurable and Nonlinear Analog Signal Processing Invited oral [Show abstract]
  • Michele Cotrufo, University of Rochester, USA
In this talk I will discuss our recent theoretical and experimental advancements in the field of computational metamaterials. I will show that, besides the well-established spatial image processing and edge detection capabilities, metasurfaces can also be used to implement temporal and spatio-temporal analog signal processing. In this context, I will discuss our recent experimental results on using optical metasurfaces as compact, scalable, and modular analog devices for temporal differentiation. I will then show how these devices can be made reconfigurable by leveraging phase-change materials. Finally, I will discuss the extension of this approach to nonlinear optics, showcasing our recent theoretical and experimental results on using nonlinear flat optics to implement analog nonlinear operations.
Media link(s):
Relevant publications:
 
https://doi.org/10.1364/OPTICA.500121
 
https://www.nature.com/articles/s41467-023-42921-z   
 
https://arxiv.org/abs/2401.06586
 
https://arxiv.org/abs/2403.09087
 
https://arxiv.org/abs/2311.13109
10:30 - Active and nonlinear microwave and THz metamaterials

Session chairperson(s): Silvio Hrabar; Cody Scarborough

10:30 - 11:00 - Some Fundamental but Rarely Discussed Properties of Passive, non-Foster, and Time-varying Matching of Small Antennas Invited oral [Show abstract]
  • Silvio Hrabar, University of Zagreb, Croatia
There are dozens of successful implementations of non-Foster and time-varying matching of small antennas, but a clear comparison with passive cases in terms of bandwidth and efficiency is often lacking. Here, we discuss the most significant differences, caused by different physical backgrounds, and their importance in practical implementations.
11:00 - 11:30 - Active Nonlinear Impedance Surfaces for Power Generation Invited oral [Show abstract]
  • Cody Scarborough, University of Colorado Boulder, USA
  • Jack Molles, University of Colorado Boulder, USA
  • Zoya Popovic, University of Colorado Boulder, USA
This paper discusses tightly coupled oscillator arrays arranged in an active surface with a period significantly smaller than a free-space wavelength. The oscillating surface is a coherent source with the EIRP proportional to the square of the number of active devices. In steady-state, a circuit model informed by field theory predicts the frequency of oscillation. The single active surface concept is extended to two self-injection locked oscillating surfaces, demonstrated with preliminary experimental results around 2 GHz with GaN HEMTs.
11:30 - 11:45 - Stability investigation of positive/negative switching capacitor Oral [Show abstract]
  • Dominik Zanic, University of Zagreb, Croatia
  • Igor Krois, University of Zagreb, Croatia
  • Silvio Hrabar, University of Zagreb, Croatia
It is shown that it is possible to design a stable positive/negative time-varying capacitor by modifying the well-known ‘disc criterion’. The analysis is verified by experiments on a prototype circuit operating in the 100 kHz-10 MHz RF band.
11:45 - 12:15 - Advances in Nonlinear Metasurfaces for Controlled THz Generation Invited oral [Show abstract]
  • Tal Ellenbogen, Tel Aviv University, Israel
We will present recent advancements in the ability of nano-engineered plasmonic metasurfaces to generate controlled broadband THz waveforms. We will discuss the underlying generation mechanisms, and demonstrate how to obtain spatiotemporal control over the amplitude, phase and polarization of the emitted THz waves, for various applications.
12:15 - 12:30 - Gyrator-based Subwavelength Radiator with Broadband Huygens Radiation Pattern Oral [Show abstract]
  • Darin Nozina, University of Zagreb, Croatia
  • Dominik Zanic, University of Zagreb, Croatia
  • Silvio Hrabar, University of Zagreb, Croatia
It is shown possible to achieve broadband directional radiation pattern using a subwavelength loop-dipole antenna (Huygens antenna) fed by a network with a gyrator.
10:30 - Metamaterials for imaging and sensing I

Session chairperson(s): Vassili Fedotov; Ekmel Ozbay

10:30 - 11:00 - Scalable and efficient photonic designs using disordered metamaterial nanounits Invited oral [Show abstract]
  • Ekmel Ozbay, Nanotechnology Research Center, Turkey
Subwavelength metamaterial nanounits can efficiently harvest electromagnetic (EM) waves, resulting in near unity light absorption in the narrow or broad frequency range. For this purpose, we explored the material and architecture requirements for the realization of light perfect absorption using these metamaterial designs from ultraviolet (UV) to far-infrared (FIR) wavelength regimes. This, in turn, opens up the opportunity of the practical application of these perfect absorbers in large scale dimensions. We adopted these lithography-free techniques in many applications including photoelectrochemical water splitting, photodetection, light emission, sensing, filtering and thermal camouflage. This presentation will summarize our recent accomplishments in scalable photonic and photoelectronic designs for various applications.
11:00 - 11:30 - Non-Local Response in Artificial Photonic Media: Planar Metamaterials vs. Metasurfaces Invited oral [Show abstract]
  • Vassili Fedotov, Skolkovo Institute of Science and Technology, Russia
We present a recently discovered planar metamaterial, which supports strong collective excitation not found in metasurfaces. The supported non-local mode is virtually dispersionless yet ensures high sensitivity of the metamaterial response to incidence angle and enables non-resonant giant angular Goos-Hänchen shift (up to 1.5 deg) in specular transmission and reflection.
11:30 - 11:45 - Metasurface Transverse Displacement Metrology by Two-photon Interference Oral [Show abstract]
  • Shufan Chen, City University of Hong Kong, Hong Kong
  • Din Ping Tsai, City University of Hong Kong, Hong Kong
In our study, we introduce an innovative experimental framework based on metasurface transverse displacement measurement and metasurface quantum interferometry. By leveraging two-photon interference and coincidence counting, our methodology achieves double-frequency quantum super-resolution. This advancement enhances phase modulation measurements associated with metasurfaces, exemplifying quantum technology’s transformative potential.
11:45 - 12:00 - Deep super-resolution optical metrology of nanostructures through a priori examination of similar class of object Oral [Show abstract]
  • Jin-Kyu So, Nanyang Technological University, Singapore
  • Eng Aik Chan, Nanyang Technological University, Singapore
  • Carolina Rendón-Barraza, Nanyang Technological University, Singapore
  • Giorgio Adamo, Nanyang Technological University, Singapore
  • Nikolay I. Zheludev, Nanyang Technological University, Singapore
We show experimentally that a deep learning-enabled analysis of intensity patterns of diffracted light allows multi-dimensional metrology of subwavelength objects with accuracy reaching λ/94. The sub-diffraction resolution is helped by the information provided by the training process that prior to the measurement gathers prior information on the diffraction patterns from similar objects. In proof of principle experiments we measure orientation and dimensions of subwavelength elliptical nanoparticles.
12:00 - 12:30 - Exploring Imaging Applications through Learning-Enhanced Metaoptics Invited oral [Show abstract]
  • Humeyra Caglayan, Tampere University, Finland
I will present the applications of metaoptics for extended depth of field and light field microscopy. In pursuit of a more compact form factor, we demonstrate that metalens can provide key advantages in imaging, such as extreme extended depth of field (EDOF), where the extended DOF range is well beyond what is demonstrated in state-of-the-art imaging. This can be further implemented in a light field microscope to obtain a compact light field microscopy with high-speed volumetric imaging and high spatio-temporal resolution.
10:30 - American Physical Society special session I

Session chairperson(s): Manolis Antonoyiannakis

10:30 - 11:00 - Poles and Zeros in Non-Hermitian Systems with Applications in Photonics Invited oral [Show abstract]
  • Felix Binkowski, Zuse Institute Berlin, Germany
  • Fridtjof Betz, Zuse Institute Berlin, Germany
  • Rémi Colom, Université Côte d’Azur, France
  • Martin Hammerschmidt, Zuse Institute Berlin & JCMwave, Germany
  • Lin Zschiedrich, Zuse Institute Berlin & JCMwave, Germany
  • Patrice Genevet, Colorado School of Mines, USA
  • Sven Burger, Zuse Institute Berlin & JCMwave, Germany
The functionality of resonant nano-photonic systems, such as metasurfaces, is determined by poles and zeros of corresponding optical response functions. We review two accurate and efficient numerical approaches for their computation based on contour integration and adaptive rational approximation, respectively. We briefly discuss applications of these approaches for design optimization of nano-photonic structures.
11:00 - 11:30 - Broadband Backscattering Reduction in a Sharply Bent Water Wave Channel Invited oral [Show abstract]
  • Vincent Pagneux, LAUM, France
  • Samantha Kucher, PMMH-ESPCI, France
  • Adrian Kozluk, PMMH-ESPCI, France
  • Philippe Petitjeans, PMMH-ESPCI, France
  • Agnès Maurel, Institut Langevin - ESPCI, France
We investigate both experimentally and numerically how to diminish the backscattering of water waves within a channel featuring multiple bends. To counteract the inherent reflection occurring at each turn of the waveguide, we employ an anisotropic metamaterial composed of closely-packed thin vertical plates.
11:30 - 12:00 - Metasurface Based Hybrid Optical Cavities for Chiral Sensing Invited oral [Show abstract]
  • Nico Baßler, Max Planck Institute for the Science of Light, Germany
  • Andrea Aiello, Max Planck Institute for the Science of Light, Germany
  • Kai Schmidt, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
  • Claudiu Genes, Max Planck Institute for the Science of Light, Germany
  • Michael Reitz, University of California San Diego, USA
I present our recent publication, where we illustrated that a stack of two metasurfaces can function as a helicity-preserving mirror. A pair of such mirrors then forms a cavity that supports circularly polarized modes. We then showed how this setup can be used to discriminate enantiomers.
12:00 - 12:30 - Loss Compensation and Virtual Gain in Metamaterials with Excitations at Complex Frequencies Invited oral [Show abstract]
  • Andrea Alù, City University of New York, USA
<p> Linear systems can be efficiently described in the frequency domain using the Fourier expansion, mapping their response onto monochromatic excitations oscillating at real-valued frequencies. We have recently explored excitations that oscillate at complex-valued frequencies, i.e., whose amplitude grows or decays exponentially in time. By exciting a lossless system with a suitably tailored complex-frequency signal – and tailoring it in a way that the system can reach a quasi-steady-state response in which it responds at the same complex frequency of the excitation - it is possible to mimic the presence of gain and/or loss without having to introduce or control the material properties. In this talk, I describe the opportunities of this approach to manipulate waves in the time-domain in photonics, radio frequency (RF), mechanics and acoustics, demonstrating that these concepts can overcome some of the limitations of passive linear responses in metamaterials.</p> <p> &nbsp;</p>
12:30 - 14:00 - Lunch Break (Tuesday)
12:30 - 13:15 - 13:45 - Shaping Journal Identity: The Editor's Role (organized by Springer Nature journals' Editors) [Show abstract]

What do editors do? Please join Dr. Cristano Matricardi (Editor, Nature Communications), Dr. Miranda Vinay (Editor, Communications Engineering) and Dr. Manolis Antonoyiannakis (Senior Associate Editor, Physical Review B, and Bibliostatistics Analyst, American Physical Society Journals) for a discussion on the mission of editorial journals, how editors define and enforce “editorial criteria” in optics and physics, what makes a great paper, the transition to open access, and finally, how editors use their role in the scientific community to support researchers. By joining voices from the Nature Portfolio and the American Physical Society Journals, the panelists will give a diverse perspective on the various approaches to academic publishing. The session is moderated by Dr. Davide Ramaccia and will be followed by a Q&A.

14:00 - 15:30 - Oral Sessions (Tuesday Afternoon 1)
14:00 - Quantum, topological and transient effects in time-varying media

Session chairperson(s): Simon Horsley; Michele Cotrufo

14:00 - 14:30 - Classical and quantum effects of dispersion in time varying metamaterials Invited oral [Show abstract]
  • Simon Horsley, University of Exeter, United Kingdom
In many studies of time varying materials, the effects of dispersion and dissipation are neglected. However, the linear response of every electromagnetic material obeys the Kramers–Kronig relations, implying that this can only be a reasonable approximation over a narrow range of frequencies. Here we apply a theory for describing time varying media, including a proper description of dispersion, including noise currents which are often overlooked. When quantum effects are important, we show that a new term arises in the theory of vacuum radiation from space–time varying media, due to noise currents within the material.
14:30 - 14:45 - Photon Transitions in Arbitrary Time-Varying Metamaterials Oral [Show abstract]
  • Artuur Stevens, KU Leuven, Belgium
  • Christophe Caloz, KU Leuven, Belgium
We present a general theory for calculating photon transitions in arbitrarily time-varying metamaterials. This theory circumvents the difficulties of conventional approaches in solving such a general problem by exploiting the eigenstates of time-dependent number operators. We demonstrate here the temporal evolution of these operators and the related transition probabilities for the cases of logistic and linear permittivity profiles. The theory is potentially extensible to arbitrary space-time modulations and may hence lead to multiple novel quantum effects and applications.
14:45 - 15:00 - Quantum amplification in time-modulated media Oral [Show abstract]
  • Antonio Ganfornina-Andrades, Public University of Navarre (UPNA), Spain
  • J. Enrique Vázquez-Lozano, Public University of Navarre (UPNA), Spain
  • Íñigo Liberal, Public University of Navarre (UPNA), Spain
We address vacuum amplification effects in time-varying media through arbitrary time-modulation profiles, introducing conjugated oscillators as a mechanical analogy to analyze the effects of transition times. Our results demonstrate that faster temporal tapering yields greater photon production from quantum vacuum amplification effects. We show how small transition times converge to near-instantaneous temporal boundaries, facilitating the simulation of systems with such characteristics. Furthermore, we explore non-trivial effects in pulsed modulations, revealing that the fastest and strongest modulation does not always maximize photon production, suggesting the need for temporal sequence design to enhance quantum phenomena.
15:00 - 15:15 - Time Topology in Synthetic Photonic Lattices Oral [Show abstract]
  • Joshua Feis, University of Rostock, Germany
  • Sebastian Weidemann, University of Rostock, Germany
  • Tom Sheppard, University of Birmingham, United Kingdom
  • Hannah Price, University of Birmingham, United Kingdom
  • Alexander Szameit, University of Rostock, Germany
Waves are shaped in time and space by their energy and momentum, respectively. Energy gaps may have topological properties, giving rise to striking features such as robust states at spatial interfaces. However, time-varying systems such as temporal metamaterials may be gapped in momentum, leading to topological states localised at time interfaces. Inspired by this, here we explore this notion of time topology based not on energy but on momentum gaps. We show that synthetic photonic lattices with suitably tailored non-Hermitian temporal variations may exhibit momentum gaps hosting time-topological states.
15:15 - 15:30 - Transient Analysis of Space-Time Frequency-Dispersive Metal Slabs Oral [Show abstract]
  • Pablo Helio Zapata Cano, Aristotle University of Thessaloniki, Greece
  • Salvador Moreno Rodríguez, Universidad de Granada, Spain
  • Stamatios Amanatiadis, Aristotle University of Thessaloniki, Greece
  • Antonio Alex-Amor, University of Pennsylvania, United States
  • Zaharias Zaharis, Aristotle University of Thessaloniki, Greece
  • Carlos Molero, Universidad de Granada, Spain
<p> In this paper, we analyze the scattering of an incident plane wave on a space-time metal slab in the presence of dispersion. Frequency dispersion is taken into account here by means of the Drude model. Analytical results, obtained via first-principle calculations, are in good agreement with in-house finite-difference time-domain (FDTD) computations.</p>
14:00 - Elastic metamaterials II

Session chairperson(s): Liangshu He; Martin Wegener

14:00 - 14:30 - Observations on the Symmetry Protected BICs of Surface Acoustic Waves Invited oral [Show abstract]
  • Liangshu He, Tongji University, Universitat Jaume I, China, Spain
  • Ricardo Martin Abraham-Ekeroth, Universitat Jaume I, Spain
  • Yabin Jin, Tongji University, East China University of Science and Technology, China
  • Daniel Torrent, Universitat Jaume I, Spain
<p> We theoretically investigate the influence of symmetry properties on the existence and properties of BICs. And confirmed that symmetry protection enhances the stability of BICs for SAWs and improves the confinement of mechanical energy. More importantly, we successfully achieved effective experimental observation of BICs for SAWs in GHz range.</p>
14:30 - 14:45 - Anomalous Frozen Evanescent Phonons Oral [Show abstract]
  • Yi Chen, Karlsruhe Institute of Technology (KIT), Germany
  • Jonathan L. G. Schneider, Karlsruhe Institute of Technology (KIT), Germany
  • Ke Wang, Karlsruhe Institute of Technology (KIT), Germany
  • Philip Scott, Karlsruhe Institute of Technology (KIT), Germany
  • Sebastian Kalt, Karlsruhe Institute of Technology (KIT), Germany
  • Muamer Kadic, Université de Franche-Comté, France
  • Martin Wegener, Karlsruhe Institute of Technology (KIT), Germany
Frozen phonons are the Bloch eigenstates of periodic elastic problems in the static (zero frequency) case. These states oscillate and decay exponentially in space. States with large decay length are of particular interest. We review our theoretical and experimental results on finite-size nonlocal 3D metamaterials made by 3D laser microprinting. These results violate St. Venant’s principle and might enable remote mechanical sensing.
14:45 - 15:00 - A Reconfigurable 1D Meta-Array Induced by Mutual Coupling Oral [Show abstract]
  • Kailun Xu, University of Oxford, United Kingdom
  • Christopher J. Stevens, University of Oxford, United Kingdom
  • Laszlo Solymar, University of Oxford, United Kingdom
  • Ekaterina Shamonina, University of Oxford, United Kingdom
Shape-morphing materials have recently garnered significant attention thanks to their great potential in such fields as robotics, telecommunications, and medicine. Here, we propose a meta-atom chain that is actuated via mutual coupling to achieve the reconfiguration of either the entire structure or its specific portions by selecting the frequency of the excitation voltage. An experiment was designed to verify the actuation mechanisms on a meta-atom chain. Our findings could pave a way for the design of micro-robots, tunable antennas, and on-orbit solar panel assembly.
15:00 - 15:15 - Experimental and Numerical Investigation on Bistable Locally Resonant Elastodynamic Metamaterials Oral [Show abstract]
  • Tugberk Guner, University of Trento, Italy
  • Oreste S. Bursi, University of Trento, Italy
  • Marco Broccardo, University of Trento, Italy
The study focuses on bistable locally resonant elastodynamic metamaterials designed for low-frequency wave attenuation. Using additive manufacturing for rapid prototyping, experimental findings underscore the significance of system identification due to the intricate dynamics. The strong nonlinearity and rapidly varying dynamics resulted in system identification beyond conventional methods.
15:15 - 15:30 - Observation of Dynamic Non-Hermitian Skin Effects in One-dimensional Mechanical System Oral [Show abstract]
  • Zhen Li, Hong Kong Baptist University, China
  • Guancong Ma, Hong Kong Baptist University, China
  • Jian-Hua Jiang, Soochow University; University of Science and Technology of China, China
<p> The dynamic properties of non-Hermitian system with skin effects have only recently started. We present the first experimental evidence of diverse non-Hermitian skin dynamics in tunable one-dimensional non-reciprocal double-chain mechanical systems with glide-time symmetry. Remarkably, various dynamic behaviors are observed with different system parameters.</p>
14:00 - Metasurface antennas and antenna arrays I

Session chairperson(s): Stefano Maci; Mats Gustafsson

14:00 - 14:30 - Duality and Complementarity Effects in Metasurface-Based Antennas Invited oral [Show abstract]
  • Stefano Maci, University of Siena , Italy
This paper examines self-dual metasurfaces (SDMs) and coupled dual metasurfaces (CDMs). SDMs are metal patterns in free space with invariant elemental cells after complementary inversion. CDMs comprise coupled complementary metal patterns. These configurations may offer improved performance in advanced antenna engineering and reflective intelligent surfaces for smart environments.
14:30 - 14:45 - Single and Double Sided Self-Dual Metasurface Coats for Enhancement of Transmission through Sub-Wavelength Apertures in Conducting Screens Oral [Show abstract]
  • Roee Geva, Tel Aviv University, Israel
  • Raphael Kastner, Tel Aviv University, Israel
Self-Dual Metasurfaces (SDMs), being inherently reflection-less, leave no outlet for a normally incident energy except for transmission and losses. We exploit this property to enrich the power density in sub-wavelength apertures in conducting screens for enhancing transmission through them by coating the nearby screen area with SDMs. Single coats are of particular interest since they can be placed in the shadowed side and yet pull in the energy from the lit region.ut your abstract here
14:45 - 15:00 - Metasurface Dome in a Semicircular Configuration for Beamforming Applications Oral [Show abstract]
  • Michela Longhi, Niccolò Cusano University, Italy
  • Stefano Vellucci, Niccolò Cusano University, Italy
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Alessio Monti, Roma Tre University, Italy
  • Mohsen Karamirad, Roma Tre University, Italy
  • Luca Stefanini, Roma Tre University, Italy
  • Davide Ramaccia, Roma Tre University, Italy
  • Filiberto Bilotti, Roma Tre University, Italy
  • Alessandro Toscano, Roma Tre University, Italy
In this study, we verify the modeling of a passive Huygens metasurface dome surrounding a pre-existing patch antenna to manipulate and focus the beam emitted by the antenna itself. Specifically, we showcase a successful method of semi-circular array pattern synthesis to model the meta-dome. This involves carefully discretizing and engineering the phase profile along the dome while considering the actual incident field generated by the antenna. Two practical examples of semi-circular passive meta-dome are proposed.
15:00 - 15:30 - Tight Antenna and Scattering Bounds Invited oral [Show abstract]
  • Mats Gustafsson, Lund University, Sweden
Fundamental limits establish boundaries on the performance of systems and devices by determining the theoretical maximum or minimum achievable performance. They provide an understanding of the trade-offs and limitations of different design choices and can assist in making more informed decisions about improving a device. Tight limits are even more valuable as they offer a more precise boundary on the performance of a design. When the limit is tight, it indicates that the difference between the theoretical maximum or minimum performance and the actual performance can be minimized, making it possible to design optimal devices. In such cases, it becomes easier to identify areas for improvement and implement changes that yield significant gains. Tight limits also enable the comparison of different designs by allowing for a more precise assessment of their relative strengths and weaknesses. Physical bounds (fundamental limitations) have recently been investigated for many radiation and scattering scenarios based on duality and convex optimization. The procedure involves optimizing sources constrained by power relations. Radiation (antenna) problems are often naturally framed as optimization over the current distribution, with a feed constrained solely by its supplied power. Consequently, the resulting bounds are valid for all antenna structures and feed locations restricted to the design region. In this presentation, we discuss the tightness of these types of limits and demonstrate that some of them are indeed tight.
14:00 - Exotic nonlinear metasystems

Session chairperson(s): Ady Arie; Ren-Min Ma

14:00 - 14:15 - Investigating Stable Soliton Propagation through a Non-Hermitian Metamaterial Oral [Show abstract]
  • Sayan Jana, Tel Aviv University, Israel
  • Bertin Many Manda, Laboratoire d'Acoustique de l'Université du Maine UMR-CNRS, France
  • Vassos Achilleos Laboratoire d'Acoustique de l'Université du Maine UMR-CNRS, Laboratoire d'Acoustique de l'Université du Maine UMR-CNRS, France
  • Dimitris Frantzeskakis, National and Kapodistrian University of Athens,, Greece
  • Lea Sirota, Tel Aviv University, Israel
In recent years, Non-Hermitian systems have garnered significant attention due to their distinct characteristics, such as accelerated wave packet propagation compared to Hermitian counterparts and non-reciprocal wave guiding capabilities. Non-reciprocity, a key feature of non-Hermiticity, can be engineered through unequal directional hopping between distinct sites. While non-reciprocal wave propagation has been extensively studied in linear systems, the synergistic effects of various non-Hermitian perturbations in nonlinear systems remain relatively unexplored. This study aims to investigate the influence of non-Hermitian constitutive parameters, encompassing non-reciprocity and loss, on soliton propagation within a one-dimensional (1D) nonlinear electric circuit. In particular, we demonstrate stable soliton propagation achieved through a particular fine-tuning of non-reciprocity and loss in the transmission line.
14:15 - 14:30 - Bound States in the Continuum for Enhancing Nonlinear Optical Chirality Oral [Show abstract]
  • Pavel Tonkaev, Australian National University, Australia
  • Ivan Toftul, Australian National University, Australia
  • Zhuoyuan Lu, Australian National University, Australia
  • Kirill Koshelev, Australian National University, Australia
  • Yuerui Lu, Australian National University, Australia
  • Yuri Kivshar, Australian National University, Australia
Bound states in the continuum (BICs) have gained a great attention recently due to their ability to engineer resonant response of photonic structures for innovative designs of optical devices. Here, we study the resonant enhancement of third-harmonic generation and tailored nonlinear chiroptical effects in metasurfaces made of hexagonal boron nitride (hBN) and supporting quasi-BIC resonance. We observe a three-order of magnitude enhancement of the third-harmonic generation for the resonant pump wavelength. We demonstrate experimentally a strong nonlinear chiral response in third-harmonic generation and large nonlinear circular dichroism varying from -0.5 to +0.5 depending on the excitation wavelength at the resonance.
14:30 - 15:00 - Reconfigurable Moiré Nanolaser Arrays With Phase Synchronization Invited oral [Show abstract]
  • Ren-Min Ma, Peking University, China
Here we propose and demonstrate moiré nanolaser arrays based on optical flatbands in twisted photonic graphene lattices, where coherent nanolasing is realized from a single nanocavity to reconfigurable arrays of nanocavities.
15:00 - 15:30 - Emulating Magnetic Spin Dynamics Using Nonlinear Optics Invited oral [Show abstract]
  • Ady Arie, Tel Aviv University, Israel
Spin transport in magnetic field can be emulated by nonlinear sum frequency generation, where the signal and idler complex amplitudes represent the two-dimensional spinor and the nonlinear coupling represents the material magnetization. This analogy is used to observe new nonlinear optical effects that are the analogues of the Stern-Gerlach effect, the topological Hall effect in skyrmions and Anderson localization of spin currents in spin glass.
14:00 - American Physical Society special session II

Session chairperson(s): Badreddine ASSOUAR

14:00 - 14:30 - Assur Graphs, Marginally Jammed Packings, And Reconfigurable Metamaterials Invited oral [Show abstract]
  • Jose Ortiz, University of Michigan, USA
  • Ethan Stanifer, University of Michigan, USA
  • Xiaoming Mao, University of Michigan, USA
Isostatic frames are mechanical networks that are simultaneously rigid and stress free. Isostaticity itself is a powerful concept in understanding phase transitions in soft matter and designing of mechanical metamaterials. We show that the contact network of marginally jammed packings approach not only isostaticity but minimal isostaticity in the thermodynamic limit. We in turn define this minimal isostaticity and describe how global non local mechanical response are hallmarks of minimally isostatic graphs (MIGs) known previously as Assur Graphs. By using the related concept of Assur Decomposition, which we generalize for periodic boundary conditions, we not only asses our claim about jammed packings but also offer a new design principle for mechanical metamaterials in which motion and stress can propagate in reconfigurable pathways, while rigidity of the entire structure is maintained. We also briefly note an apparent relationship between fully repulsive interactions, and the emergence of MIGs at the un-jamming point.
14:30 - 15:00 - Sound waveguiding by spinning Invited oral [Show abstract]
  • Mohamed Farhat, KAUST, Saudi Arabia
  • Pai-Yen Chen, University of Illinois at Chicago, USA
  • Ying Wu, KAUST, Saudi Arabia
We propose an approach to waveguiding in acoustics by inducing spinning within a column of air, altering acoustic refractive indices. This concept may lead to the development of an airborne acoustic analog to optical fibers and nonreciprocal waveguiding mechanisms.
15:00 - 15:30 - Topological and Nonreciprocal Phenomena of Surface Acoustic Wave in On-chip Phononic Lattices Invited oral [Show abstract]
  • Yoichi Nii, Tohoku University, Japan
Surface acoustic wave (SAW) devices serve a versatile platform in both classical and quantum technologies. Here, we present unique SAW phenomena based on nanoscaled phononic lattices, which include gigahertz topological SAW and nonreciprocal resonant scattering of SAW. These novel properties may pave an avenue to further development of SAW technologies.
15:30 - 16:00 - Coffee Break (Tuesday Afternoon)
16:00 - 17:30 - Oral Sessions (Tuesday Afternoon 2)
16:00 - Theoretical aspects of time-modulated media

Session chairperson(s): Dimitrios Sounas; Marie Touboul

16:00 - 16:30 - A Reciprocity Theorem for Time-Modulated Media Invited oral [Show abstract]
  • Dimitrios Sounas, Wayne State University, USA
  • Sander Mann, City University of New York, USA
  • Andrea Alu, City University of New York, USA
In this paper, we show how the reciprocity theorem can be generalized to time-variant media with arbitrary modulation, and show how this general form of reciprocity can be used in the analysis of thermal emission from such media.
16:30 - 17:00 - Non-Reciprocity For The Time-Modulated Wave Equation And Diffusion Equation Through The Lens Of High-Order Homogenization Invited oral [Show abstract]
  • Marie Touboul, UMI 2004 Abraham de Moivre-CNRS, Imperial College London, London SW7 2AZ, UK, United Kingdom
  • Bruno Lombard, Aix-Marseille Univ, CNRS, Centrale Marseille, LMA UMR 7031, Marseille, France, France
  • Raphaël Assier, Department of Mathematics, University of Manchester, Oxford Road, Manchester, M13 9PL, UK, United Kingdom
  • Sébastien Guenneau, The Blackett Laboratory, Department of Physics, Imperial College London, London, SW7 2AZ, UK , United Kingdom
  • Richard Craster, Department of Mathematics, Imperial College London, London SW7 2AZ, UK, United Kingdom
Laminated media with material properties modulated in space and time in the form of travelling waves exhibit non-reciprocity. Contrary to previous belief, we show for both the wave and diffusion equations that effective media with a single time-modulated parameter are non-reciprocal, provided homogenization is pushed to the second order.
17:00 - 17:30 - Space-Time Metamaterials: Their Modeling and Time-Domain Physical Limitations Invited oral [Show abstract]
  • Martin Stumpf, Lulea University of Technology, Sweden
  • Jonas Ekman, Lulea University of Technology, Sweden
  • Giulio Antonini, University of L'Aquila, Italy
Analytical and computational electromagnetic field modeling of time-varying metamaterials will be discussed. Moreover, in order to assess their performance directly in the original (space-time) domain, we shall analyze their time-domain physical limitations.
16:00 - Elastic metamaterials III

Session chairperson(s): Corentin Coulais; Vincent Pagneux

16:00 - 16:30 - Animating metamaterials with topological solitons Invited oral [Show abstract]
  • Corentin Coulais, University of Amsterdam, Netherlands
In this talk I will demonstrate how quintessential nonlinear waves—topological solitons—can be generated and driven in mechanical metamaterials to achieve advanced on demand mechanical tasks: non-commutative response, non-reciprocal nonlinear wave guiding and filtering and robotic manipulation and locomotion.
16:30 - 16:45 - Reconfigurable Elastic Metasurface For The Multifunctional Wave Manipulation Based On The Timoshenko–Ehrenfest Beam Theory Oral [Show abstract]
  • Geon Lee, Pohang University of Science and Technology, Korea (South)
  • Junsuk Rho, Pohang University of Science and Technology, Korea (South)
Our innovative development introduces a versatile metasurface based on the Timoshenko–Ehrenfest beam theory. This showcases diverse wave behaviors across various frequencies. Unlike traditional elastic metasurfaces tailored to specific uses, our method combines differently shaped components on a single substrate. This enables precise control over refraction, focusing, self-acceleration, and complete reflection. By employing the Timoshenko–Ehrenfest beam theory, our analytical model closely aligns with numerical and experimental results. It incorporates comprehensive harmonic simulations and visually documented field observations. Furthermore, our system significantly improves piezoelectric energy capture in the focusing setup, validating its practicality. With envisioned applications in structural monitoring, wireless sensing, and the Internet of Things, our adaptable elastic metasurface, backed by the Timoshenko–Ehrenfest beam theory, is poised for widespread adoption.
16:45 - 17:00 - Hard-Magnetic Soft Mechanical Metamaterials: Mechanics, Design, and Wave Manipulations Oral [Show abstract]
  • Quan Zhang, University of Galway, Ireland
  • Stephan Rudykh, University of Galway, Ireland
Hard-magnetic active elastomers (hMAEs) consist of magnetizable particles embedded in a soft matrix. Their ability to rapidly and reversibly change the shape and properties under remote magnetic stimuli, makes them an attractive material platform for human-technology interfaces, soft robotics, actuators and sensors, and biomedical devices. Here, we propose to exploit the unique transformative ability of hMAEs integrated into the metamaterial design to develop novel tunable hard-magnetic soft mechanical metamaterials with superior elastic wave properties.
17:00 - 17:15 - Bandgap modulation in active metamaterial beams through feedback control Oral [Show abstract]
  • Marcin B. Kaczmarek, Delft University of Technology (TU Delft), Netherlands
  • Vivek Gupta, Delft University of Technology (TU Delft), Netherlands
  • S. Hassan HosseinNia, Delft University of Technology (TU Delft), Netherlands
Piezoelectric metastructures with resonators implemented through feedback control create tunable low-frequency bandgaps in compact designs and enable advanced control techniques in the metamaterial context. For such structures, the influence of varying the cross-section of the base substrate on bandgap generation is related to the changes in electromechanical and stiffness coefficients.
17:15 - 17:30 - Nonreciprocal frequency conversion in nonlinear contact chains Oral [Show abstract]
  • Beomseok Oh, Pohang University of Science and Technology (POSTECH), Korea (South)
  • Yeongtae Jang, Pohang University of Science and Technology (POSTECH), Korea (South)
  • Junsuk Rho, Pohang University of Science and Technology (POSTECH), Korea (South)
<p> In this work, we present a nonreciprocal frequency conversion in nonlinear contact chains, stemming from combining nonlinearities with broken spatial symmetry and local resonances. We exploit a one-dimensional nonlinear chain based on the Hertz law, comprised of cylindrical rods. Through both experimental and numerical investigations, we illustrate nonreciprocal upward and downward frequency conversions in a bi-directional manner, all accomplished without a conventional wave-mixing scheme.</p>
16:00 - Metasurface antennas and antenna arrays II

Session chairperson(s): David González Ovejero; Christos Bilitos

16:00 - 16:30 - On the Use of Higher Order Modes for Dual-Polarized Modulated Metasurface Antennas Invited oral [Show abstract]
  • David González Ovejero, CNRS, France
This contribution presents a new structure that enables dual-polarized radiation with aperture antennas based on modulated metasurfaces. The desired dual-polarized radiation is achieved by exciting in a self-dual impedance plane two orthogonally polarized modes that are phase matched. To that end, we tailor dispersion characteristics of the first two higher order transverse magnetic (TM) and transverse electric (TE) modes in the dielectric slab. The radiation characteristics will be presented for reactance planes modulated along one direction and for two-dimensional concentric modulations.
16:30 - 16:45 - Over 70 Gb/s Data Transmission Rate with 300-GHz-band Transmission-type Beamforming Metasurface for Beyond-5G Wireless Communication Oral [Show abstract]
  • Adam Pander, NTT Device Technology Laboratories, NTT Corporation, Japan
  • Hibiki Kagami, NTT Device Technology Laboratories, NTT Corporation, Japan
  • Hiroshi Hamada, NTT Device Technology Laboratories, NTT Corporation, Japan
  • Daisuke Kitayama, NTT Device Technology Laboratories, NTT Corporation, Japan
  • Hiroyuki Takahashi, NTT Device Technology Laboratories, NTT Corporation, Japan
This study presents multilayer beamforming metasurface devices at 300-GHz-band with continuous 2π phase designability. The fabricated devices showed beam steering angles between 18 and 38. The first-ever wireless data transmission with beam steering at 300 GHz using metasurfaces is demonstrated, achieving over 72 Gb/s data rate over a 25-cm link distance in 16QAM modulation.
16:45 - 17:00 - A Novel Low-Profile Continuous Transverse Stub Array with Multi-Beam Operation Enabled by a Reflecting Luneburg Metasurface Lens Oral [Show abstract]
  • Christos Bilitos, Univ. Rennes, Institut d'Électronique et des Technologies du numéRique (IETR), France
  • Ronan Sauleau, Univ. Rennes, Institut d'Électronique et des Technologies du numéRique (IETR), France
  • Stefano Maci, University of Siena, Italy
  • David González-Ovejero, CNRS, Institut d'Électronique et des Technologies du numéRique (IETR), France
This study introduces a compact, multi-beam antenna that operates over a wide bandwidth in the K-band. The design consists of a dual-layer structure, with the bottom layer housing a reflecting Luneburg lens (RLL) to direct multiple planar wavefronts towards a continuous transverse stub (CTS) array in the top layer. The orientation of the wavefronts is determined by the positioning of sources in the lower layer. When exciting the CTS, they allow for the creation of focused beams. The orientation of these beams is determined by the alignment of the slots on the upper layer relative to the wavefront direction. Unlike conventional variable inclination continuous transverse stubs (VICTS), which depend on mechanical adjustments for scanning, our design facilitates beam scanning by simply switching the input ports. This all-metal, low-profile antenna structure achieves broadband 2D scanning by beam-switching at the K-band.
17:00 - 17:15 - Broadband Design of Reflective Multi-Resonator Metasurface for V-Band Applications Oral [Show abstract]
  • Dipankar Saha, University of Luxembourg, Luxembourg
  • Andreas E. Olk, IEE Smart Sensing Solutions, Luxembourg
  • Linlong WU, University of Luxembourg, Luxembourg
  • Bhavani Shankar M. R., University of Luxembourg, Luxembourg
In this work, we present a meta-atom synthesis approach for passive metasurfaces of subwavelength thickness using the description in terms of surface impedance. The approach includes an optimization procedure that aims for broadband single resonance structures with 2π phase coverage which are easy to fabricate. The motivation of this work is to develop a passive, large aperture, multi-resonator phase-gradient metasurface for sensing applications in V band (60-64 GHz).
17:15 - 17:30 - Miniaturized Dual-Polarized Antenna with High Isolation Based on Spoof Plasmonic Metamaterial for 5G Application Oral [Show abstract]
  • Zhang Wen Cheng, Southeast University, China
  • Hui Feng Ma, Southeast University, China
The structure based on spoof surface plasmon polaritons (SSPPs) exhibits higher phase constant, which can make it possible to reduce structure size effectively. In this paper, a miniaturized dual-polarized antenna based on SSPPs is proposed. According to the slow-wave characteristic of SSPPs, the total antenna size is reduced to 0.4λ0×0.4λ0. The miniaturized antenna with feeding network is designed completely and its good ±45 radiation performance and high isolation level of over 30dB are verified by simulations.
16:00 - Nonlinear flat optics

Session chairperson(s): Costantino De Angelis; Femius Koenderink

16:00 - 16:30 - Analog computing with nonlinear flat optics Invited oral [Show abstract]
  • Costantino De Angelis, University of Brescia - CNR INO, Italy
  • Domenico de Ceglia, University of Brescia - CNR INO, Italy
Digital signal processing has revolutionized many fields of science and engineering, but it still shows critical limits; a long-sought solution is optical analog computing. We demonstrate here that nonlinear phenomena combined with engineered nonlocality in flat optics can be leveraged to synthesize Volterra kernels able to outperform linear devices.
16:30 - 17:00 - Light emitting and nonlinear metasurfaces – dark lines with unexpected surprises Invited oral [Show abstract]
  • Femius Koenderink, AMOLF, Netherlands
Metasurfaces that support high-Q Fano resonances due to bound states in the continuum offer unique opportunities as linear and nonlinear light emitting metasurfaces. We are interested in the spatiotemporal physics and control of these intrinsically multimode structures. We report new techniques to map temporal dynamics and beating of near fields in BIC systems, and discuss strategies for spatiotemporal control of nonlinear light generation. Finally we challenge common wisdom by observing that adding loss can generate high Q BICs.
17:00 - 17:15 - Perovskite Metasurfaces for Electrically Driven Spin-polarized Polariton Luminescence and Lasing Oral [Show abstract]
  • Yutao Wang, Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore , Singapore
  • Giorgio Adamo, Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore , Singapore
  • Son Tung Ha, Institute of Materials Research and Engineering, (A*STAR), Singapore, Singapore
  • Jingyi Tian, Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore , Singapore
  • Cesare Soci, Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, Singapore , Singapore
Optoelectronic control of exciton polaritons is inherently challenging due to the charge neutrality of the polaritons. Here we show that active perovskite metasurfaces supporting bound states in the continuum are ideal platforms for both optical and electrical generation and control of exciton polaritons. We analyze the role of in- and out-of-plane symmetries for the realization of spin-polarized exciton polariton lasing, and the electrical selection of their spin state by controlling the exciton injection in a light-emitting metatransistor.
17:15 - 17:30 - Optical Joule-Thomson Expansion in Coupled Waveguide Arrays Oral [Show abstract]
  • Marco Steffen Kirsch, Universität Rostock, Germany
  • Giorgos G. Pyrialakos, University of Southern California, USA
  • Richard Maximilian Altenkirch, Universität Rostock, Germany
  • Nikolaos V. Kantartzis, Aristotle University of Thessaloniki, Greece
  • Tom A. W. Wolterink, Universität Rostock, Germany
  • Mercedeh Khajavikhan, University of Southern California, USA
  • Alexander Szameit, Universität Rostock, Germany
  • Matthias Heinrich, Universität Rostock, Germany
  • Demetrios N. Christodoulides, University of Southern California, USA
We experimentally observe an all-optical Joule-Thomson expansion process in discrete multimoded nonlinear systems. To this end, we show that power injected from a single lattice site can predominantly condense into the fundamental mode of a larger waveguide lattice under the influence of nonlinearity.
16:00 - Metamaterials for energy and environment

Session chairperson(s): Miguel Beruete; Michela Longhi

16:00 - 16:30 - Radiative Cooling Using Cement Based Composites Invited oral [Show abstract]
  • Jorge S. Dolado, Centro de Física de Materiales, CFM (CSIC-UPV/EHU), Spain
  • Guido Goracci, Centro de Física de Materiales, CFM (CSIC-UPV/EHU), Spain
  • Silvia Arrese-Igor, Centro de Física de Materiales, CFM (CSIC-UPV/EHU), Spain
  • Andrés Ayuela, Centro de Física de Materiales, CFM (CSIC-UPV/EHU), Spain
  • Angie Torres, Public University of Navarre, Spain
  • Iñigo Liberal, Public University of Navarre, Spain
  • Juan J. Gaitero, TECNALIA, Basque Research and Technology Alliance (BRTA), Spain
  • Matteo Cagnoni, Politecnico di Torino, Italy
  • Federica Cappelluti, Politecnico di Torino, Italy
  • Alicia E. Torres, Public University of Navarra, Spain
  • Ridwan O. Agbaoye, Centro de Física de Materiales, CFM (CSIC-UPV/EHU), Spain
  • Laura Carlosena, Public University of Navarra, Spain
  • Carlos Lezaun, Public University of Navarre, Spain
  • Miguel Beruete, Public University of Navarre, Spain
The escalating challenges of global warming necessitate efficient cooling solutions. Passive radiative cooling (PRC) emerges as a sustainable alternative, leveraging Earth's natural heat dissipation mechanism through direct radiation to outer space within the atmospheric window (AW). This study explores the potential of concrete and cement-based materials for PRC applications, focusing on Portlandite and Tobermorite. Experimental measurements and theoretical calculations demonstrate their high reflectance in the solar spectrum and good emissivity in the AW. Climatic analysis reveals positive nighttime radiative cooling for both materials, with Portlandite exhibiting positive daytime PRC in select regions. These findings underscore the significance of cement-based materials for sustainable cooling technologies.
16:30 - 16:45 - Optimized Distributed Bragg Reflectors designed by Artificial Intelligence for Multilayered Radiative Cooling Metamaterials Oral [Show abstract]
  • David Osuna Ruiz, Universidad Pública de Navarra, Spain
  • Maite Áznarez-Sanado, Asociación de la Industria Navarra, Spain
  • Pilar Herrera-Plaza, Asociación de la Industria Navarra, Spain
  • Miguel Beruete, Universidad Pública de Navarra, Spain
A full numerical study combining artificial intelligence (AI) methods and electromagnetic simulations on a multilayered structure for radiative cooling, made of nanometer-thick layers that make a Bragg mirror for the solar irradiance window, is performed. The structures are optimized in terms of maximizing net cooling power, leading to unconventional layer thickness distributions.
16:45 - 17:00 - Coherent Perfect Absorption of Light in a Single Nanowire Oral [Show abstract]
  • Luka Vignjevic, University of Southampton, United Kingdom
  • Nikitas Papasimakis, University of Southampton, United Kingdom
  • Eric Plum, University of Southampton, United Kingdom
  • Nikolay Zheludev, University of Southampton, United Kingdom
Whereas absorption of travelling waves is an inherently stochastic process, standing waves can be deterministically absorbed by a flat thin absorber – a phenomenon known as coherent perfect absorption (CPA). Here, we extend CPA to absorbers of lower dimensionality and report that, upon reflection in a conical mirror, radially polarized light can be deterministically absorbed in a single nanowire. Conversely, azimuthally polarized light can be fully reflected. Such phenomena are of interest for energy harvesting and for the detection of topologically structured light, including “Flying Donuts” and orbital angular momentum-carrying beams.
17:00 - 17:15 - Inverse Designed Solar Spectral Splitter for Lateral Tandem Solar Cells Oral [Show abstract]
  • Marie Louise Schubert, Karlsruhe Institute of Technology, Germany
  • Thomas Sturges, Karlsruhe Institute of Technology, Germany
  • Jan David Fischbach, Karlsruhe Institute of Technology, Germany
  • Larry Lüer, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
  • Christoph Brabec, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
  • Carsten Rockstuhl, Karlsruhe Institute of Technology, Germany
Lateral tandem solar cells absorbing in different wavelength ranges are cost-efficient to produce and allow us to upscale solar energy production. In this project, we inverse design the height profile of two free-form metasurfaces to spectrally split the incident light to the preferred solar cell at multiple incidence angles.
17:15 - 17:30 - Metal-free Design of a Multilayered Metamaterial with Chirped Bragg Grating for Enhanced Radiative Cooling Oral [Show abstract]
  • David Osuna Ruiz, Universidad Pública de Navarra, Spain
  • Carlos Lezaun, Universidad Pública de Navarra, Spain
  • Alicia Elena Torres-García, Universidad Pública de Navarra, Spain
  • Miguel Beruete, Universidad Pública de Navarra, Spain
A wideband, all-dielectric metamaterial for enhancing radiative cooling, based on the principles of Bragg gratings, is investigated. It is optimized to reflect most of the solar irradiance window (between 0.3 μm–3 μm), a main challenge for these technologies. Numerical results show that reflection can be easily tailored and the net cooling power maximized without using metallic components.
17:30 - 18:30 - Poster Sessions (Tuesday Afternoon)
17:30 - Poster session

Session chairperson(s): Anna Theodosi; Ioannis Spanos

1 - Spontaneous Emission in a Dielectric Cube--Graphene Substrate Gap Poster [Show abstract]
  • Julieta Olivo, Universidad de Buenos Aires, Departamento de Física, IFIBA (CONICET)., Argentina
  • Hernán Ferrari, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Universidad Austral, Facultad de Ingeniería., Argentina
  • Mauro Cuevas, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Universidad Austral, Facultad de Ingeniería., Argentina
This work deals with the spontaneous emission study of a point-like emitter placed in close proximity of a graphene dielectric structure. This structure is formed by a dielectric micro-cube placed above a plane graphene sheet covering a dielectric substrate. The electromagnetic interplay between the emitter and the fields scattered back to the emitter's site by the cube and the graphene substrate drives the emitter to modify the field emission rate. The size of the micro-cube, the graphene constitutive parameters, as well as the gap between dielectric cube and graphene determine the enhancement level of the spontaneous emission decay rate. We have developed a method based in the coupled dipole approximation including the surface Green tensor to take into account the scattering with the graphene substrate. We show that the results obtained by using the rigorous theory can be well approximated by those calculated by extracting the plasmonic contribution from the surface Green tensor.
2 - Multiscale Approach For Studying Nonlinear Properties Of Molecular Metamaterials Poster [Show abstract]
  • Mariia Poleva, Karlsruher Institut für Technologie, Germany
  • Benedikt Zerulla, Karlsruher Institut für Technologie, Germany
  • Carsten Rockstuhl, Karlsruher Institut für Technologie, Germany
  • Ivan Fernandez-Corbaton, Karlsruher Institut für Technologie, Germany
  • Marjan Krstic, Karlsruher Institut für Technologie, Germany
A novel computational framework that couples quantum and optical simulations is utilized to study bulk and surface contributions to the second--harmonic signal. We consider two examples: second--harmonic fields generated from a film of gold--cysteine layered material and second--harmonic circular dichroism from a monolayer of chiral BINOL molecules on a substrate.
3 - Toward a T-Matrix-Based Multiple Scattering Framework for Acoustic Metastructures Poster [Show abstract]
  • Nikita Ustimenko, Karlsruhe Institute of Technology, Germany
Powerful computational tools are indispensable for designing acoustic metastructures. Whereas comparable codes are well-established for electromagnetic metamaterials, acoustic metamaterials received less attention. We explore an efficient computational approach, based on the multipolar T-matrices, and demonstrate its utility in several cases, including single-particle and multi scattering problems.
4 - A Reconfigurable Metasurface Based on Plasma Cylinders Poster [Show abstract]
  • Jiaruo Yan, Foundation for Research and Technology-Hellas, Greece
  • Ioannis Draganidis, Foundation for Research and Technology-Hellas, Greece
  • Ioannis Katsantonis, Foundation for Research and Technology-Hellas; University of Crete, Greece
  • Alessio Monti, Roma Tre University, Italy
  • Stefano Vellucci, Niccol`o Cusano University, Italy; Metamorphose-VI, Belgium, Italy
  • Mirko Barbuto, Niccol`o Cusano University, Italy; Metamorphose-VI, Belgium, Italy
  • Filiberto Bilotti, Roma Tre University, Italy; Metamorphose-VI, Belgium, Italy
  • Maria Kafesaki, Foundation for Research and Technology-Hellas; University of Crete, Greece
A reconfigurable metasurface based on an array of plasma cylinders is investigated and numerically demonstrated. Analytical results for single-cylinder scattering properties are shown, providing guidelines for optimising the cylindrical scatterers. Full wave numerical investigations show that a reconfigurable structure with tunable transmission can be realised by controlling the plasma electromagnetic properties. Potential implementation for beam steering is discussed.
5 - Deformable Wire Media Resonators Poster [Show abstract]
  • Mykola Khobzei, Yuriy Fedkovych Chernivtsi National University, Ukraine
  • Vladyslav Tkach, Yuriy Fedkovych Chernivtsi National University, Ukraine
  • Serhii Haliuk, Yuriy Fedkovych Chernivtsi National University, Ukraine
  • Andrii Samila , Yuriy Fedkovych Chernivtsi National University, Ukraine
  • Svitlana Matsenko, Technical University of Denmark, Denmark,
  • Toms Salgals, Riga Technical University,, Latvia
  • Vjaceslavs Bobrovs, Riga Technical University, Latvia
  • Pavel Ginzburg , Tel Aviv University, Israel
  • Constantin Simovski , Aalto University, Finland
  • Dmytro Vovchuk, Tel Aviv University, Israel
<p> A temporal degree of freedom opens new capabilities to control electromagnetic interactions with structured media. While fast, comparable to the carrier oscillation period, changes in effective material susceptibilities suggest emerging new peculiar phenomena, experimental realizations of lag theoretical predictions. However, phenomena, inspired by slow practically realizable parametric changes in effective media, have both fundamental interest and immediate practical applications. Here we perform comprehensive studies of modal hierarchy in a deformable Fabry-Perot resonator, constructed from a wire array, hosted in a compressible dielectric host. The lattice parameter of the wire media can be controlled over a 5-fold range (between 10 and 50mm), leading to superior electromagnetic tunability. Furthermore, the resonator response demonstrates an extreme sensitivity to mechanical deformation as resonance hierarchy in metamaterial assembly strongly depends on the lattice constant. Specifically, a 0.3 mm change in the lattice constant, being as small as ~0.002λ, shifts the Fabry-Perot resonance frequency around 1.9 GHz. Owing to their extraordinary responsivity, deformable electromagnetic metamaterials can find use as elements in adaptive user-controlled devices.</p>
6 - Metamaterial-based Soft Grippers For Harvesting Fragile Crops Poster [Show abstract]
  • Diego Guzman, University of Groningen, Netherlands
Robot-assisted harvesting of delicate fruits is a technological challenge due to the contradictory requirements on robotic grippers that must deliver conformal grasping and versatile plucking without damaging the crops. To address this problem, we propose a robotic gripper with two extended fingers and a removable metamaterial layer, the topological structure of which is optimized for a proper balance between stiff and soft behavior and advanced conformability to diverse fruit shapes. We prove the advanced grasping functionality of the gripper numerically and experimentally by handling truss tomatoes.
7 - Enhancement of Plasmo-photonic Index Sensor Sensitivity by Slow-light Effects Poster [Show abstract]
  • Eleftheria Lampadariou, University of Ioannina, Greece
We present a systematic theoretical study of integrated plasmo-photonic sensors decorated by Bragg cavity configurations. The Bragg cavities incorporate slow-light effects into the surface plasmon polariton (SPP) propagation, which enhance the SPP/analyte interaction and boost the sensor performance up to an order of magnitude compared to the corresponding undecorated one. To comprehensively study the physics of such systems we use a simplified analytical model based on the transfer matrix method (TMM) and validate the findings by explicit 2D finite-difference time-domain (FDTD) simulations. Exploration of all design parameters provides the theoretical performance limits.
8 - Tuning the Resonant Properties of 3D Metamaterial Unit Cells via Anisotropic Coupling Mechanisms Poster [Show abstract]
  • Ioannis Spanos, University of Oxford, United Kingdom
  • Christopher John Stevens, University of Oxford, United Kingdom
  • Ekaterina Shamonina, University of Oxford, United Kingdom
A 3D cubic metamaterial with tunable resonant properties was fabricated and characterised experimentally. The cube comprises spiral resonators fabricated with Field's metal injection. The coupling between them changes depending on their relative orientation. This anisotropy was utilised in a 3D cube, allowing to tune the number of resonant peaks appearing.
9 - UV Enhancement of MoS2 Monolayer Photoluminescence Poster [Show abstract]
  • Mahan Bakhshikhah, Central European Institute of Technology, Brno University of Technology, Czech Republic
  • Jiří Liška, Central European Institute of Technology, Brno University of Technology, Czech Republic
  • Ondřej Červinka, Central European Institute of Technology, Brno University of Technology, Czech Republic
  • Jindřich Mach, Central European Institute of Technology, Brno University of Technology - Faculty of Mechanical Engineering, Institute of Physical Engineering, Brno University of Technology, Czech Republic
  • Tomáš Šikola, Central European Institute of Technology, Brno University of Technology - Faculty of Mechanical Engineering, Institute of Physical Engineering, Brno University of Technology, Czech Republic
We present that the optical response of thin and tiny metasurface flat optics based on exciton resonances can be enhanced by improving the photoluminescence properties of their semiconducting building blocks made of a MoS2 monolayer by their treatment using UV laser.
10 - Topological Invariants In Space-time Photonic Systems With Travelling Wave Modulation Poster [Show abstract]
  • Alejandro Caballero, Universidad Autónoma de Madrid, Spain
  • Paloma Huidobro, Universidad Autónoma de Madrid, Spain
In this work, we study the topological properties of systems whose optical parameters are modulated in a travelling wave form. More precisely, we focus on how the Zak phase is defined in such systems, as well as examining the bulk-boundary correspondence and the associated robust edge-states.
11 - Measurement of the Vibration Reduction of a circular Saw Blade with an integrated vibroacoustic Metamaterial in the rotating State Poster [Show abstract]
  • Sebastian Rieß, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Ron Schmidt, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Nikolai Kleinfeller, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • William Kaal, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Heiko Atzrodt, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
Circular saw blades are thin-walled disk-shaped structures which are prone to vibrations excited by the sawing process, leading to high sound pressure levels. In the presented work a saw blade with an integrated vibroacoustic metamaterial is experimentally investigated in the rotating state for its structural dynamic behavior up to rotational speeds of 3000 rpm. The saw blade is excited with an impulse hammer and measured with a stationary laser Doppler vibrometer. A stop band, which does not shift in frequency with increasing rotational speed is obtained in the frequency range of 1900 - 2500 Hz. Adjacent modes, splitting up due to rotation, do not propagate into the stop band with increasing rotational speed.
12 - Unpatterned planar ultrathin TiOxNy/TiO2/Ti films as solar absorbers Poster [Show abstract]
  • Luca Mascaretti, Czech Technical University in Prague, Czech Republic
  • Pavel Kwiecien, Czech Technical University in Prague, Czech Republic
  • Ladislav Kalvoda, Czech Technical University in Prague, Czech Republic
  • Ivan Richter, Czech Technical University in Prague, Czech Republic
Solar-thermal conversion is an attractive strategy to collect sunlight and transform it into heat that is directly utilized or further transformed into electricity. Solar absorber materials must be carefully designed to achieve the highest solar absorptance and they must feature materials able to withstand repeated thermal cycling. In this contribution, we discuss a simple unpatterned metal/insulator/metal (MIM) absorber based on TiOxNy/TiO2/Ti. We show the optimization of optical absorption by numerically computing optical spectra for different values of the TiN and TiO2 thickness in the ranges 0–35 nm and 0–75 nm, respectively. As a result, the optimized structure TiOxNy (10 nm)/TiO2 (40 nm)/Ti exhibits ~ 75% optical absorption in the 250–2000 nm range, outperforming a counterpart based on Au and on metallic TiN. Such structures may be experimentally realized by Atomic Layer Deposition (ALD) on large areas.
13 - Cross-shaped resonators for BICs in mid-IR fabricated using multiphoton lithography Poster [Show abstract]
  • Savvas Papamakarios, IESL-FORTH, Greece
  • Ioannis Katsantonis, IESL-FORTH, Greece
  • Maria Kafesaki, IESL-FORTH, Greece
  • Kosmas L. Tsakmakidis, NKUA, Department of Physics, Greece
  • Maria Farsari, IESL-FORTH, Greece
In this work we study the excitation of quasi-BICs resonances in cross-shaped metamaterials for mid-IR using symmetric and asymmetric features in three different designs. Furthermore, the designs are constructed using multiphoton lithography and further processed using electroless silver plating to obtain the metallo-dielectric metamaterials.
14 - Design of an Underwater 3D Positioning System for Verifying Focusing Performance of Underwater Acoustic Metamaterial in a Water Tank Poster [Show abstract]
  • Sea-Moon Kim, KRISO, Korea (South)
  • Yeong-Sung Choo, KRISO, Korea (South)
  • Jeong-Bin Jang, KRISO, Korea (South)
  • Beomseok Oh, POSTECH, Korea (South)
  • Dongwoo Lee, POSTECH, Korea (South)
  • Junsuk Rho, POSTECH, Korea (South)
  • Seong-Hoon Byun, KRISO, Korea (South)
A test of underwater acoustic measurement in a water tank is required for the performance verification of metamaterials for underwater sound. An underwater 3D positioning system was developed for the performance test and a simple tank experiment has been done for checking its testability. We found that clear tone signal is observed by removing reflected waves. An underwater acoustic metamaterial was fabricated and the focusing performance was measured with the developed underwater 3D positioning system.
15 - Application of vibroacoustic metamaterial to compensate continuum resonance in powertrain mounting systems for electric vehicles Poster [Show abstract]
  • Nikolai Kleinfeller, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Georg Stoll, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Heiko Atzrodt, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Thomas Hansen, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
  • Moritz Hülsebrock, Fraunhofer Institute for Structural Durability and System Reliability LBF, Germany
The concept of vibroacoustic metamaterials applied to elastomeric engine mounts is proven. An engine mount is optimized using a virtual design process, prototypically produced, and experimentally validated. It is shown that vibracoustic metamaterials are a valid design for passive, nonfluidic engine mount with beneficial behavior with respect to the vibration transmission.
16 - Design and fabrication of a free-floating metalens Poster [Show abstract]
  • Mahdi Shanei, Chalmers University of Technology, Sweden
  • Mindaugas Juodenas , Institute of Materials Science, Kaunas University of Technology, Lithuania
  • Mikael Käll , Chalmers University of Technology, Sweden
Immersion lenses with smaller focal areas than free-space are suitable components for applications such as microscopy and optical manipulation. Here, we have designed and fabricated a self-aligning water-immersion metalens that together with a low numerical aperture (NA) objective emulates a high NA water-immersion objective. We have considered doughnut-shaped silicon-based metalens, with a NA of 0.85. The spatial position of the metalenses can be dynamically controlled through the optical gradient force arising from the Gaussian profile of the incident beam produced by the primary low NA objective. To validate our approach, we conducted experiments to trap 800 nm polystyrene (PS) beads in two dimensions with free-floating metalenses. We envisage that these freely moving metalenses can be customized to enable the optical manipulation of particles and find applications across various immersion technologies.
17 - High-dimensional Quantum Random Number Generation by Metalens Array Poster [Show abstract]
  • Shufan Chen, City University of Hong Kong, Hong Kong
  • Din Ping Tsai, City University of Hong Kong, Hong Kong
The technique of Quantum Random Number Generation (QRNG) is widely recognized for generating true random numbers due to inherent security benefits from quantum effects. Our research paper presents a high-dimensional, compact QRNG system using a metalens array. Unlike current commercial products, our system doesn’t require post-randomness extraction, streamlining the QRNG process and offering an efficient integrated solution.
18 - Large-scale, Mass-produced Bilayer Meta-Devices Enabling Advanced Applications: Chiral Imaging and Beyond Poster [Show abstract]
  • Jingcheng Zhang, City University of Hong Kong, Hong Kong
  • Din Ping Tsai, City University of Hong Kong, Hong Kong
Information channel of optical polarization has been widely researched in traditional optical devices. However, the development of miniature, broadband, tunable, and scalable chiral meta-devices has been restricted due to integration and large-scale production challenges. In this work, we experimentally demonstrated a chiral imaging meta-device with large-area and broadband chiral control using nanoimprint lithography technology, forming centimeter-scale Moiré pattern. The discussion focuses on Ponting vectors, singular features in the near field, and the chiral optical response in the far field. The proposed Moiré meta-device can achieve circular dichroism (CD) greater than 10%, demonstrating the potential of using CD mechanisms for chiral imaging. It holds significant application prospects in various fields, such as encryption and security, materials science, biochemistry, and medicine.
19 - Optical Spintronics Poster [Show abstract]
  • Ilya Deriy, ITMO University, Russia
  • Danil Kornovan, ITMO University, Russia
  • Andrey Bogdanov, ITMO University, Russia
In this work, we present the concept of optical spintronics, which uses optical spin rather than electromagnetic energy to transfer information. We show that transfer of optical spin is possible without energy transfer, and present an optical spin diode - a device that support non-reciprocal propagation of optical spin currents.
20 - Nonreciprocal Metasurfaces with Selective Polarization using Circularly and Linearly Polarized Patch Radiators Poster [Show abstract]
  • David Chatzichristodoulou , Fredeick Research Center, RF and Microwave Solutions LTD, Cyprus
  • Photos Vrionides, Frederick Research Center, Frederick Univeersity, Cyprus
  • Dimitra Psichogiou, Tyndall National Institute, School of Engineering, University College Cork, Ireland
  • Symeon Nikolaou, Frederick Research Center, Frederick Univeersity, Cyprus
The manuscript presents the designs of two nonreciprocal / directional metasurfaces (MSFs) operating in the 3.5 GHz frequency band. The first one presents a Circular Polarization to Circular Polarization (CP-to-CP) MSF where the MSF cell consists of a circularly polarized patch antenna with truncated corners in each side of the multi-layer surface with the use of transistors along the signal path. A similar method with two transistors and a via that connects the radiators in each side, is also used for the second case, where a circular polarization to linear polarization (CP-to-LP) MSF is implemented with the converted propagated linearly polarized wave to be selectively chosen between two orthogonal polarizations. The two transistors along the transmission lines deny the propagation along the opposite direction and they enhance the propagated wave in the preferred direction.
21 - Trampoline Metamaterials For Multiband Amplified Piezoelectric Energy Harvesting Poster [Show abstract]
  • Geon Lee, Pohang University of Science and Technology, Korea (South)
  • Junsuk Rho, Pohang University of Science and Technology, Korea (South)
We developed an efficient piezoelectric energy-harvesting platform that works well at both low and high frequencies. Unlike previous systems limited to high frequencies, our design, using a trampoline metamaterial, excels in electrical output. It extends the bandgap for high frequencies and creates a wide bandgap for low frequencies. Through experiments, we demonstrate effective trapping of flexural waves, converting them into high-performance electrical energy. Our platform shows a significant increase in output compared to traditional designs, making it a promising renewable energy source for various applications such as structural health monitoring and sensor technologies.
22 - Single Point Diamond Turning Process of Piezoelectric Single Crystal for Fabrication Approach of Ultrasonic Metamaterial Poster [Show abstract]
  • Jun Sae Han, Korea Institute of Machinery and Materials, Korea (South)
  • Dong-Hyun Seo, Korea Institute of Machinery and Materials, Korea (South)
  • Eun-ji Gwak, Korea Institute of Machinery and Materials, Korea (South)
  • Tae-Jin Je, Korea Institute of Machinery and Materials, Korea (South)
  • Eun-chae Jeon, University of Ulsan, Korea (South)
  • Doo-Sun Choi, Korea Institute of Machinery and Materials, Korea (South)
Single point diamond turning process has been developed for fabrication approach of piezoelectric single crystal. As making the surface of single crystal into curved structure, acoustic field modulation was attempted to studied. Especially for ultrasonic metamaterial application, flat, single sided curved, double sided curved, micro-patterned structure was fabricated and assembled into ultrasound transducer. Only with the single point diamond turning process, there was tiny crack defects on the surface of it according to spoke direction, but fabricated transducer showed focusing characteristics on the underwater test experiment.
23 - Near-infrared Photonic Routing Based on GST/a-Si Bilayer Metasurfaces Poster [Show abstract]
  • JUNJIE LI, Institute of Physics, Chinese Academy of Sciences, China
Photonic routing holds immense significance in fields of photonic integrated circuits (PICs) for free-space optical linking. Here, we report a Ge2Sb2Te5 (GST)-based bilayer metasurfaces with 4-level codable unit pixels, which realize controllable photonic routing in near-infrared region. Each unit pixel can be designated with desired states. Further, we demonstrated polarization conversion modulation of the tunable metasurfaces comprising identical unit cell with large cross-polarization switching (≈55%) around 1550 nm. Moreover, we prototyped the metasurfaces with coded unit pixels to realize designated photonic routing. The metasurfaces with 4-level programmability portend a new paradigm in NIR photonic routing for PICs.
24 - Ultrafast excitation of surface plasmon-polariton through optically induced diffraction grating in GaAs films Poster [Show abstract]
  • Olesia Pashina, ITMO University, Russia
  • Olga Sergaeva, University of Brescia, Department of Information Engineering, Italy
  • Albert Seredin, ITMO University, Russia
  • Constantino De Angelis, University of Brescia, Department of Information Engineering, Italy
  • Mihail Petrov, ITMO University, Russia
We introduce a theoretical model describing femtosecond optically induced processes in a GaAs film. The model is used to study the evolution of permittivity under illumination by two plane waves. Resulting periodic interference pattern induces diffraction grating that enables the excitation of a surface plasmon polariton at the film-substrate interface.
25 - A self-consistent simulation framework for modelling graphene-based optoelectronics in the THz regime Poster [Show abstract]
  • Spyros Doukas, Physics department, National and Kapodistrian University of Athens, Greece
  • Anastasios Koulouklidis, IESL - FORTH, Greece
  • Stelios Tzortzakis, IESL - FORTH, Greece
  • Maria Kafesaki, IESL - FORTH, Greece
  • Elefterios Lidorikis, University of Ioannina, Greece
  • Anna Tasolamprou, Physics department, National and Kapodistrian University of Athens, Greece
We present a multiphysics simulation framework for modelling graphene optoelectronics in the THz regime. Our model accounts for graphene’s electrical, optical and thermal properties and the interplay between them. Excellent agreement with experiments highlights the potential of our simulation framework for designing graphene-based optoelectronic devices in the THz spectrum.
26 - Compliant Mechanism Based Planar Inductors For Reconfigurable Magneto-Inductive Wave Devices Poster [Show abstract]
  • Norbert Seliger, Technical University of Applied Sciences Rosenheim, Germany
  • Nico Leirich, Technical University of Applied Sciences Rosenheim, Germany
A reconfigurable planar inductor based on bistable compliant mechanism is proposed. Flexible snapping of wire elements is used for modification of the loop area and self inductance as well as for the mutual coupling between laterally arranged multiple inductors in a magneto-inductive wave (MIW) device. A mechanical model is presented building the basis for an analytical inductance model. The bistable reconfigurability is demonstrated experimentally and confirmed by numerical simulation results.
27 - Hierarchical Topological States in Three Dimensional Phononic System Poster [Show abstract]
  • MD. ANZAN-UZ- ZAMAN, Okayama University, Japan
  • Yusuke Hata, Okayama University, Japan
  • Kenji Tsuruta, Okayama University, Japan
We have designed a novel three dimensional (3D) structural model for demonstrating higher order (HO) topological states of acoustic-wave propagation. Based on a stacked honeycomb structure, we show that two-dimensional (2D) surface state and one dimensional (1D) hinge state can be numerically designed through a hierarchical property of phononic band. Due to its simple stacking structure, the model presented here is expected to be easier for fabrication than the existing proposed models and thus may serve as a prototype for designing 3D integration of acoustic-wave devices for information transmission.
28 - Topology Optimization of Frequency Selective Surfaces for Radar Absorbing Structures Poster [Show abstract]
  • Jinbong Kim, Korea Institute of Materials Science, Korea (South)
  • Hong-Kyu Jang, Korea Institute of Materials Science, Korea (South)
  • Jaecheol Oh, Korea Institute of Materials Science, Korea (South)
This study presents the topology optimization of frequency selective surfaces placed on radar absorbing composite laminates in X-band. The frequency selective surfaces are coded with 24 by 24 bitmap matrices. Optimization results for the different periodicities presented good absorbing performance covering the whole X-band frequency range: 8 GHz – 12 GHz.
29 - Gold nanorod multilayer targets for coherent perfect absorption Poster [Show abstract]
  • András Szenes, University of Szeged, Department of Optics and Quantum Electronics, Hungary
  • Dávid Vass, University of Szeged, Department of Optics and Quantum Electronics, Hungary
  • Emese Tóth, University of Szeged, Department of Optics and Quantum Electronics, Hungary
  • Balázs Bánhelyi, University of Szeged, Department of Computational Optimization, Hungary
  • Mária Csete, University of Szeged, Department o Optics and Quantum Electronics, Hungary
3D periodic metamaterial composed of six layers of sub-wavelength 2D nanorod arrays were optimized numerically to achieve effective parameters enabling coherent perfect absorption (CPA). Using two different compositions, targets with CPA capabilities were successfully designed around the central wavelength of 795 nm. By tuning the geometry and monitoring the effective parameters, impedance-matched targets were designed providing full and phase-dependent transmission.
30 - Epsilon-Near-Zero Metamaterials Constructed With Active Core-Shell Nanoresonators Poster [Show abstract]
  • Dávid Vass, University of Szeged, Department of Optics and Quantum Electronics, Hungary
  • András Szenes, University of Szeged, Department of Optics and Quantum Electronics, Hungary
  • Emese Tóth, University of Szeged, Department of Optics and Quantum Electronics, Hungary
  • Balázs Bánhelyi, University of Szeged, Department of Computational Optimization, Hungary
  • Mária Csete, University of Szeged, Department of Optics and Quantum Electronics, Hungary
Targets seeded with high density multilayers of periodic active core-shell nanoresonator patterns were studied to create epsilon-near-zero materials. Comparative study was performed of nanoresonators embedding and coated with the gain material, considerong the optical response, near-field enhancement (NFE), effective parameters and the impact of oblique incidence.
31 - A New Compact Ultra-Thin Circularly Polarized True Metasurface Antenna Poster [Show abstract]
  • Alireza Ghaneizadeh, Constructor University, Germany
  • Sören F. Peik, Hochschule Bremen, Germany
  • Martin Schneider, University of Bremen, Germany
  • Mojtaba Joodaki, Constructor University, Germany
Put your abstract hereWe present a novel design for a True Metasurface Antenna (TMA) that is compact, ultrathin, and inspired by a circularly polarized microstrip antenna array. This approach involves modifying the feed point location and incorporating a rectangular slot on top metallic layer of each electrically small resonator. This ultra-thin antenna efficiently occupies a small area of 1.62λ0× 1.62λ0 at the resonance frequency of 5.8 GHz. In addition, this TMA has a gain of over 14 dBi and is comprised of two layers of Rogers RO4003 substrate. Each layer has a thickness of 0.813 mm and there is no additional air gap between the layers. Numerical results show that the proposed circularly polarized TMA has a radiation efficiency of 87.48% and an aperture efficiency of 81.16% at 5.8 GHz.
32 - Comparison of High-Order Floquet Modes Frequency Behavior in Refractive Metasurfaces Synthesized With Two Different Approaches Poster [Show abstract]
  • Alexander Zhuravlev, ITMO University, Russia
  • Ilya Voropaev, ITMO University, Russia
  • Alexey Kosmynin, MatrixWave LLC, Russia
  • Juan Domingo Baena, Universidad Nacional de Colombia, Colombia
  • Andrey Sayanskiy, ITMO University, Russia
In this work we present the results of a comparison of higher-order Floquet modes frequency behavior in case of spatially non-uniform refractive metasurface designed with two different approaches. First approach is based on the use of a multilayer frequency selective surface and another one is based on broadband reflectionless Huygens metasurface.
33 - Imaging With Positive Gradient Index Elastic Lenses Poster [Show abstract]
  • Paolo Han Beoletto, Department of Applied Science and Technology, Politecnico di Torino, Italy
  • Fabio Nistri, Department of Applied Science and Technology, Politecnico di Torino, Italy
  • Antonio Stefano Gliozzi, Department of Applied Science and Technology, Politecnico di Torino, Italy
  • Nicola Maria Pugno, Laboratory for Bio-inspired, Bionic, Nano, Meta Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Italy
  • Federico Bosia, Department of Applied Science and Technology, Politecnico di Torino, Italy
Positive gradient index elastic lenses are the elastic counterpart of the optical convex lens. These lenses differ from other GRIN lenses as they demonstrate the ability to image point-like sources, establishing a one-to-one relation between the position of the object and of the image.
34 - A Circularly Polarized Transmit-Reflect-Array Antenna Based on Transmission–Reflection-Integrated Metasurface Poster [Show abstract]
  • Shi Sun, Southeast University, China
  • Hui Feng Ma, Southeast University, China
In this paper, we proposed a circularly polarized (CP) transmit-reflect-array antenna based on transmission–reflection-integrated metasurface. The metasurface can not only realize arbitrary amplitude allocation of transmitted and reflected CP waves but also independently manipulate their phase responses. By adopting the transmission and reflection amplitude to be equally allocated and full-space phase control, the transmit-reflect-array antenna can achieve high-gain beams in both the reflection and transmission space. The simulated results show that the designed transmit-reflect-array antenna can achieve good performance, which may find promising applications in satellite communication with bidirectional communication scenarios.
35 - Integrated manipulation for surface and spatial wave based on a programmable topological metasurface Poster [Show abstract]
  • Qiang Xiao, Southeast University, China
A programmable topological metasurface is presented to realize flexible electromagnetic manipulation of surface waves and spatial waves. Under the excitation of a surface or spatial wave, the programmable metasurface can regulate the formation of different topological guided wave paths of surface waves and spatial waves with different scattering beam angles.
36 - Extracting Permittivity and Permeability using a Position-Insensitive and Calibration-Independent Transmission/Reflection Method in a Rectangular Waveguide Poster [Show abstract]
  • James Denemark, Air Force Institute of Technology, USA
  • Michael Havrilla, Air Force Institute of Technology, USA
  • Hircsh Chizever, The Delta Sigma Company, USA
This paper proposes a position-insensitive and calibration-independent method to extract a material's permittivity and permeability from a rectangular waveguide using one empty measurement and two sample measurements of different thickness.
37 - Design And Optimization Of Bright Magnetic Optical Sources Poster [Show abstract]
  • Joshua Davis, Université de Bordeaux, Centre National de la Recherche Scientifique, Centre de Recherche Paul Pascal, France
  • Alexandre Baron, Université de Bordeaux, Centre National de la Recherche Scientifique, Centre de Recherche Paul Pascal, Institut Universitaire de France, France
The design of nanoresonators which modify the local density of states to enhance the magnetic Purcell effect while suppressing the electric Purcell effect is investigated. Quasinormal modes are used to efficiently design and optimize bright magnetic optical emitters by controlling the Purcell enhancements at the transition frequency of Eu3+.
38 - Laser-Induced Glass Nano-Structuring for Enhanced Optical Properties and Damage Threshold. Poster [Show abstract]
  • Evangelos Skoulas, Biomimetic., Greece
  • Rytis Buzelis, Center for Physical Sciences and Technology, Lithuania
  • Mindaugas Gedvilas, Center for Physical Sciences and Technology, Lithuania
This research investigates laser-induced nanostructuring to engineer versatile spatial nano-features on dielectric surfaces, specifically targeting anti-reflection properties. Additionally, it explores methods for enhancing the laser-induced damage threshold (LIDT) on silica optical flats using femtosecond pulse techniques, resulting in a notable augmentation of transmission and LIDT across diverse wavelengths. These insights carry substantial implications for the advancement of optics and laser-induced materials processing methodologies.
39 - Multistatic Imaging of Meta-Shells Poster [Show abstract]
  • Gregory Samelsohn, Shamoon College of Engineering, Israel
In this presentation, we review our recent results and some new ideas concerning both direct and (mainly) inverse wave scattering by hollow meta-shells, i.e., closed, generally semi-transparent metasurfaces. It is shown that these meta-shells can be characterized by a singular potential. In the most general case of Huygens’ metasurfaces with magneto-electric coupling, the wave scattering is described by a four-parameter family of point interactions, derived previously within 1D quantum mechanics. The singularity of the potential is utilized here to convert the boundary value problem into a volume integral equation. Then, a linear noniterative inversion algorithm is used to recover the support of the scattering potential, and therefore, the shape of the meta-shell. Scalar 2D simulations of a TM-polarized wave, normally incident on a cluster of cylindrical meta-shells, confirm the validity of the method.
40 - Quad-Band Incident Angle Insensitive Metamaterial Absorber for S, C and X-Band Applications Poster [Show abstract]
  • Bahar İla, Konya Technical University, Turkey
  • Ercan Yaldiz, Konya Technical University, Turkey
In this work, incidence angle insensitive quad-band metamaterial absorber (MMA) is presented for S, C, and X-band applications. The designed MMA structure consists of a resonator layer, dielectric layer, and ground plane. The resonator layer comprises three closed rings. The structure has been designed and analyzed using Ansys HFSS full-wave electromagnetic (EM) simulation software. The reported percentage of absorptions are 99.79%, 98.84%, 99.86%, and 98.98% at 2.01 GHz, 3.51 GHz, 7.26 GHz, and 9.41 GHz, respectively.
41 - Elastic Temporal Anti Reflection Coating Poster [Show abstract]
  • Fabio Nistri, Politecnico di Torino, Italy
  • Antonio S. Gliozzi, Politecnico di Torino, Italy
  • Federico Bosia, Politecnico di Torino, Italy
As already proven in optics, waves propagating in a medium with a timemodulated impedance undergo a time scattering mechanism in which the reflected and transmitted waves exhibit frequency conversion and wavelength conservation. This time modulation can be designed to obtain a reflectionless propagation by tuning the refractive index time modulation, thus creating a temporal Anti-Reflection Coating in time. In this study, we show that the same concept can be applied to elastic waves in a homogeneous nondispersive medium with time-modulated mechanical properties, e.g., wave velocity. We demonstrate through numerical simulations that elastic waves exhibit the same properties as their optical counterpart, such as wavelength conservation and frequency conversion. In addition, the wave velocity variation can be linearized, preserving the antireflection design.
42 - Visible to Near-IR Tunable Plasmons in Nanoporous Gold Films Poster [Show abstract]
  • JASPREET SINGH, Indian Institute of Technology Ropar (IIT Ropar), India
This study explores the synthesis and characterization of nanoporous gold (NPG) films fabricated using a straightforward chemical etching method. Atomic force microscopy (AFM) was employed to examine the surface morphologies of NPG samples with varying film thicknesses, revealing a progressive transition from plain gold films to nanoporous structures as the thickness increases. Analysis of root-mean-square roughness (RMS) and porosity unveiled a significant dependence on film thickness, underscoring the intricate interplay between etching kinetics and film growth dynamics. Additionally, UV-Vis characterization in reflection mode showcased the tunability of plasma edge and plasmon frequency, suggesting the potential for customizing optical properties through film thickness adjustment. Overall, this research provides valuable insights into the controlled synthesis and characterization of NPG films, with implications for applications in plasmonics, sensing, and beyond.
43 - Near-Field Light Localization In Quasiperiodic Metasurfaces Poster [Show abstract]
  • Vitthal Mishra, Department of Physics, Instituto Superior Técnico, Universidade de Lisboa, Portugal
  • Miguel Gonçalves, CeFEMA-LaPMET, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Portugal
  • Mario Silveirinha, Instituto Superior Técnico, Universidade de Lisboa and Instituto de Telecomunicações, Portugal
  • Pedro Ribeiro, CeFEMA-LaPMET, Departamento de Física, Instituto Superior Técnico, Universidade de Lisboa, Portugal
  • Marco Piccardo, Department of Physics, Instituto Superior Técnico, Universidade de Lisboa, Portugal
We identify the signature of near-field light localization in the transition from periodic to quasiperiodic dielectric metasurfaces. These results highlight the potential of quasiperiodicity in meta-optics design for the engineering of near-field landscapes.
18:30 - 20:00 - Special Event in Memory of Prof. Costas Soukoulis
11 September 2024 / Start time: 9 h 0 min
09:00 - 10:00 - Plenary Session IV
09:00 - Plenary Session IV

Session chairperson(s): Yakir Hadad

09:00 - 10:00 - Spatiotemporal Control of Passive and Active Multimode Systems Plenary
  • Hui Cao, Yale University, USA
10:00 - 10:30 - Coffee Break (Wednesday Morning)
10:30 - 12:30 - Oral Sessions (Wednesday Morning)
10:30 - Complex effective media

Session chairperson(s): Owen Miller; Ariel Epstein

10:30 - 11:00 - Pronounced Nonlocal DC Conduction In A Metamaterial Invited oral [Show abstract]
  • Julia A. Iglesias Martinez, Karlsruhe Institute of Technology (KIT), Germany
  • Yi Chen, Karlsruhe Institute of Technology (KIT), Germany
  • Muamer Kadic, Karlsruhe Institute of Technology (KIT), Germany
  • Martin Wegener, Karlsruhe Institute of Technology (KIT), Germany
<p> Ohm’s law of electric conduction is local in the sense that the current density at one position only depends on the electric field at that very same position. Because of locality, the resistance of an ordinary metallic wire is simply proportional to its length. Here, we discuss and demonstrate nonlocal metamaterial wires that exhibit pronounced deviations from local behavior. Specifically, they exhibit oscillations of their electric resistance versus wire length.</p>
11:00 - 11:30 - Low-Loss ENZ Metamaterials Invited oral [Show abstract]
  • Owen Miller, Yale University, USA
Surprising phenomena for many applications can be enabled at wavelengths where the real part of a material’s permittivity is near zero. A key hurdle for many of these phenomena at optical frequencies is material loss, with typical material quality factors of 5 or smaller. We use the theory of composites to identify a pathway, using typical materials, to design ENZ metamaterials with substantially smaller losses, offering order-of-magnitude improvements in material quality factors at the ENZ point.
11:30 - 11:45 - Artificial Magnetism via Mie Resonances Oral [Show abstract]
  • Alessandra Contestabile, University of L'Aquila, Italy
  • Giuseppe Castaldi, University of Sannio, Italy
  • Vincenzo Galdi, University of Sannio, Italy
  • Angelo Galante, University of L'Aquila, Italy
  • Marcello Alecci, University of L'Aquila, Italy
  • Denis Burov, University of L'Aquila, Italy
  • Carlo Rizza, University of L'Aquila, Italy
Generally, artificial magnetism is realized by considering the average response of complex metamaterials structures. However, these standard approaches break down at deeply subwavelength scales. Here, we suggest a route for achieving artificial magnetism for near-field manipulations. We show that, at a Mie resonance, a high-index hollow sphere can support an outer near-field distribution accurately reproducing the one of a negative-permeability hollow sphere with the same size.
11:45 - 12:00 - Effective-medium properties of dense plasmonic balls Oral [Show abstract]
  • Alexandre Baron, University of Bordeaux, CRPP, CNRS, France
  • Ranjeet Dwivedi, ENSEMBLE 3, Centre of Excellence, Poland
  • Ashod Aradian, University of Bordeaux, CRPP, CNRS, France
  • Virginie Ponsinet, University of Bordeaux, CRPP, CNRS, France
  • Kevin Vynck, Univ. Claude Bernard Lyon 1, CNRS, ILM, France
The electromagnetic behavior of dense plasmonic balls under plane wave illumination is investigated. High-precision T-matrix numerical calculations are used to compute the response of such balls for varying radii and volume fractions of gold nanoninclusions, up to 44\%. The average scattered field is accurately reproduced by that of a spatially dispersive homogeneous sphere characterized by three effective-medium parameters: an electric permittivity $varepsilon_mathrm{eff}$, a magnetic permeability $mu_mathrm{eff}$ and a wave vector $k_mathrm{L}$, associated to a longitudinal mode. Our results show that artificial magnetism can arise in the presence of strong interparticle couplings even when the inclusions exhibit no magnetic dipole. We also reveal the importance of the longitudinal mode to accurately reproduce the fields internal to the ball.
12:00 - 12:30 - Dark Matter Search Using Metamaterial-Based Tunable High Quality Factor Microwave Cavities Extended oral [Show abstract]
  • Rustam Balafendiev, ITMO University, Russia
  • Pavel Belov, ITMO University, Russia
Tunable microwave cavities based on wire metamaterials are designed. The cavities form a base for haloscopes for detection of the axions. The axions are candidates for dark matter particles. The research is perform within the activity of the ALPHA Consortium.
10:30 - Elastic metamaterials IV

Session chairperson(s): Sebastien Guenneau; Matthieu Malléjac

10:30 - 11:00 - A Seismic Metasurface From The Bronze Age Withdrawn [Show abstract]
  • Stephane Brule, Institut Fresnel, Aix-Marseille University, CNRS, Centrale Marseille, France
  • Bogdan Ungureanu, Imperial College London and Le Mans Universite, UK and France
  • Stephane Enoch, Institut Fresnel, Aix-Marseille University, CNRS, Centrale Marseille, France
  • Sebastien Guenneau, Imperial College London, UK
<p> Our work is concerned with the dynamic surface response of stone settlements from the middle Bronze age obtained with seismic ambient noise techniques near the city of Carnac in French Brittany in July 2019. So called menhirs present local resonances in the [10,50] Hz frequency range, which is of interest for ground vibration mitigation in earthquake engineering.</p>
11:00 - 11:15 - Electromagnetic mechanical model for pressure sensitive metamaterial absorbers Oral [Show abstract]
  • Sandra Rodini, University of Pisa, Italy
  • Simone Genovesi, University of Pisa, Italy
  • Giuliano Manara, University of Pisa, Italy
  • Filippo Costa, University of Pisa, Italy
A thin absorbing structure employing Polydimethylsiloxane (PDMS) substrate is studied both from an electromagnetic and mechanical point of view. The proposed model allows to link the anisotropic dielectric permittivity of the PDMS substrate to the applied deformation and thus study the frequency and amplitude properties of the electromagnetic absorption.
11:15 - 11:30 - Design and in field validation of a modular metamaterial for mitigation of railway induced vibrations Oral [Show abstract]
  • Fabio Nistri, Politecnico di Torino, Italy
  • Antonio Gliozzi, Politecnico di Torino, Italy
  • Federico Bosia, Politecnico di Torino, Italy
  • Luca D'Alessandro, Phononic Vibes s.r.l., Italy
  • Stefano Caverni, Phononic Vibes s.r.l., Italy
  • Paul Charkaluk, Phononic Vibes s.r.l., Italy
  • Alberto Corigliano, Politecnico di Milano, Italy
  • Marco Miniaci, CNRS, France
  • Andrea Colombi, ETH Zürich, Switzerland
  • Nicola Pugno, Università di Trento, Italy
Metamaterials are artificial structures exhibiting wave control properties that can be exploited in civil engineering applications. Among them, locally resonant metamaterials are able to control and manipulate wave propagation at wavelengths several times larger than the unit cell size, and can therefore be useful for low frequency vibration suppression. This work presents the design, installation and validation of a 0.4 m thick metamaterial-based panel for mitigation of railway-induced vibrations. The barrier comprises a cubic locally resonating unit made of four concrete pyramids connected together by external slender steel rebars. The unit cell is characterized from the dynamic point of view both numerically and experimentally, and a full-scale field test is then performed on the barrier validating the effectiveness of the metamaterial-based panel in providing a low frequency mitigation of 10 dB at the resonance frequency around 30 Hz, in good agreement with the numerical and laboratory tests.
11:30 - 11:45 - Aerodynamic Flow Induced Tunable Piezoelectric Metamaterial For Wave Attenuation In Aircraft Wing Oral [Show abstract]
  • Sunny Sunny, IIT Madras, India
  • Senthil Murugan, IIT Madras, India
The objectives of this paper are to (1) propose the piezoelectric metamaterial wing without a significant increase in the overall weight of wings, (2) develop the transfer matrix method for wave propagation analysis that includes aerodynamic effects, and (3) explore the new band gap formations, due to interaction of piezoelectric metamaterials with aerodynamic flow, for flexural wave attenuation in UAV wing. This study shows the interaction of piezoelectric metamaterial and aerodynamic flow to obtain tunable bandgaps for vibration wave attenuation in UAV wings without increasing its electric power or weight constraints.
11:45 - 12:00 - Fatigue Prediction for Metallic Additively Manufactured Lattice Components Using FCM Based on Average Strain Energy Density Approach Oral [Show abstract]
  • Raffaele De Biasi, University of Trento, Italy
  • Oguz Oztoprak, Technical University of Munich, Germany
  • Filippo Zanini, University of Padova, Italy
  • Simone Carmignato, University of Padova, Italy
  • Filippo Berto, University of Rome Sapienza, Italy
  • Stefan Kollmannsberger, Bauhaus-Universitat Weimar, Germany
  • Matteo Benedetti, University of Trento, Italy
This work tackles the challenge of accurately predicting fatigue life in metal additive manufactured lattice structures. Utilizing the Finite Cell Method and X-ray computed tomography, the study analyzes the as-built lattice structure's geometry, employing the average strain energy density method. This proof of concept demonstrates excellent agreement, providing precise fatigue life predictions for the analyzed metamaterial.
12:00 - 12:30 - Bi-stability in non reciprocal robotic topological metamaterial Extended oral [Show abstract]
  • Rupesh Mahore, University of Amsterdam, Netherlands
  • Xiaofei Guo, University of Amsterdam, Netherlands
  • Corentin Coulais, University of Amsterdam, Netherlands
<p> The principle of reciprocity is ubiquitous in most of the physical systems and is often violated in out-of-equilibrium systems, extensively studied in past few decades. While most of the studies typically describe a mono-stable non equilibrium steady state, here we induced topological non orient-ability in robotic metamaterial interacting non reciprocally to get multiple steady states. Through numerical simulations, experiments and theory we demonstrate that these states can be isolated within a region in parameter space and non orientability further enhances the robustness and control over these states.</p>
10:30 - Tunable metasurfaces for scattering engineering

Session chairperson(s): Philipp del Hougne; Mirko Barbuto

10:30 - 11:00 - Physical-Model-Based Wave Control in Metasurface-Programmable Complex Systems: Theory, Model Calibration, and Applications Invited oral [Show abstract]
  • Philipp del Hougne, CNRS, IETR - Univ Rennes, France
I discuss our recent results on (i) various equivalent formulations of compact physics-compliant models of wave scattering in metasurface-programmable complex media in terms of coupled dipoles, scattering matrices or impedance matrices; (ii) how to estimate these models’ parameters in full-wave simulations or experimentally in frugal manners (e.g., with phase-insensitive measurements) and with minimal ambiguity; (iii) some applications to previously inaccessible wave control functionalities (e.g., tuning a reconfigurable chaotic cavity to a coherent perfect absorption (CPA) state and identifying the CPA wavefront without ever measuring phase) and optimal blind non-invasive focusing on perturbation-inducing targets in complex media.
11:00 - 11:30 - Reflecting and Transmitting Metasurfaces for Composite Vortex Generation Invited oral [Show abstract]
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Mohsen Karamirad, Roma Tre University, Italy
  • Michela Longhi, Niccolò Cusano University, Italy
  • Alessio Monti, Roma Tre University, Italy
  • Davide Ramaccia, Roma Tre University, Italy
  • Luca Stefanini, Roma Tre University, Italy
  • Stefano Vellucci, Niccolò Cusano University, Italy
  • Andrea Alù, City University of New York, USA
  • Filiberto Bilotti, Roma Tre University, Italy
  • Alessandro Toscano, Roma Tre University, Italy
This contribution explores the design and implementation of metasurfaces capable of manipulating and generating composite vortex beams. By exploiting reflective or transmissive elements, metasurfaces offer unprecedented control over the spatial amplitude and phase distribution of reflected or transmitted fields, enabling the generation of complex vortex structures and the implementation of simple reconfiguration strategies. The study investigates the underlying principles and implementation techniques, demonstrating the efficacy of reflective and transmitting metasurfaces in generating composite vortex beams with tailored properties.
11:30 - 11:45 - Design of Self-Reconfigurable Huygens Metasurfaces for Antenna Applications Oral [Show abstract]
  • Stefano Vellucci, Niccolò Cusano University, Italy
  • Alessio Monti , Roma Tre University, Italy
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Ashif Fathnan, Nagoya Institute of Technology, Japan
  • Mohsen Karamirad, Roma Tre University, Italy
  • Michela Longhi, Niccolò Cusano University, Italy
  • Davide Ramaccia, Roma Tre University, Italy
  • Luca Stefanini, Roma Tre University, Italy
  • Hiroki Wakatsuchi, Nagoya Institute of Technology, Japan
  • Alessandro Toscano, Roma Tre University, Italy
  • Filiberto Bilotti, Roma Tre University, Italy
In recent years, phase-gradient Huygens metasurfaces (HMS) have emerged as a promising technology for beam-steering and beam-forming applications in antennas. Traditionally, HMSs have been designed with fixed responses tailored to specific frequencies limiting their adaptability in dynamic environments. In this contribution, we introduce the design of self-reconfigurable HMSs capable of adjusting their phase gradients in response to both the frequency and temporal waveform of impinging signals. We discuss a design procedure for synthesizing the reconfigurable cells, leveraging a cascade configuration of reactive impedance sheets. We show that a dynamic phase modulation can be achieved through a careful selection and manipulation of the impedance layers.
11:45 - 12:15 - Selected Advances in Beam-forming Metastructures and Metasurfaces Invited oral [Show abstract]
  • Vasileios Ataloglou, University of Toronto, Canada
  • Alexander MacKay, University of Toronto, Canada
  • George Eleftheriades, University of Toronto, Canada
Three developments in beam-forming with metastructures and metasurfaces are presented. First, a metastructure is presented where the phase-addition property of mixers is used to significantly reduce the number of beamformers in an electrically-scanned antenna system with reconfigurable amplitude distribution. A beam-shaping scheme is also presented along with measured array factors. Secondly, amplitude and phase shaping with a reconfigurable reflective metasurface is demonstrated. Lastly, a passive metasurface design for anomalous reflection that maintains high directivity at a fixed angle over a broad bandwidth is proposed.
12:15 - 12:30 - Superscatterers for Radar Visibility Oral [Show abstract]
  • Pavel Ginzburg, Tel Aviv University, Israel
  • Dmytro Vovchuk, Tel Aviv University, Israel
  • Anna Mikhailovskaya, Tel Aviv University, Israel
  • Konstantin Grotov, Tel Aviv University, Israel
  • Anton Kharchevskii, Tel Aviv University, Israel
  • Andrey Machnev, Tel Aviv University, Israel
  • Denis Kolchanov, Tel Aviv University, Israel
  • Dmitry Dobrykh, Tel Aviv University, Israel
Experimental demonstration of superdirectivity and superscattering is among the long-standing challenges in electromagnetic theory. An appealing approach to increase a scattering cross-section is accommodating several spectrally overlapping resonances within a subwavelength structure. In this contribution, we will present several strategies to design superscatterers with the aid of generic optimization and demonstrate their state-of-the-art performances experimentally. A solution to an emerging problem of small UAV tracking and monitoring with the aid of radar-visible superscatterers will be demonstrated.
10:30 - Metamaterials for imaging and sensing II

Session chairperson(s): Filippo Costa; FEI DING

10:30 - 10:45 - How To Image An Arbitrary Size And Shape Objects From The Far-field With Deeply Subwavelength Resolution Oral [Show abstract]
  • Benquan Wang, Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore
  • Sergei Kurdiumov, Centre for Photonics Metamaterial and Optoelectronics Research Centre, University of Southampton, UK
  • Ruyi An, School of Computer Science and Engineering, Nanyang Technological University, Singapore
  • Giorgio Adamo, Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore
  • Eng Aik Chan, Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore
  • Yewen Li, School of Computer Science and Engineering, Nanyang Technological University, Singapore
  • Zexiang Shen, Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore
  • Bo An, School of Computer Science and Engineering, Nanyang Technological University, Singapore
  • Nikolay I. Zheludev, Centre for Disruptive Photonic Technologies, Nanyang Technological University and Centre for Photonics Metamaterial and Optoelectronics Research Centre, University of Southampton, Singapore and UK
We demonstrate a new universal technique for super-resolution imaging of arbitrary shape and size objects. We present the object as an array of super-pixels each of which is resolved with resolution far beyond the diffraction limit. The high resolution of the limited size individual super-pixels - that are close to the size of a diffraction limited hotspot - is achieved by the deep learning analyzing the diffraction patterns of light scattered on them using a deep learning-process a priori trained on a limited set of random super-pixels. The proof of principle experiments demonstrate that resolution of the technique depends on the size of the training set and easily exceeds the resolution of conventional confocal microscopy.
10:45 - 11:00 - Experimental Realization of the Slepian-Pollak Tomographic Imaging: Super-Resolution for Limited-size Objects Oral [Show abstract]
  • Taeyong Chang, Nanyang Technological University, Singapore
  • Giorgio Adamo, Nanyang Technological University, Singapore
  • Jin-Kyu So, Nanyang Technological University, Singapore
  • Eng Aik Chan, Nanyang Technological University, Singapore
  • Nikitas Papasimakis, University of Southampton, UK
  • Yijie Shen, Nanyang Technological University, Singapore
  • Nikolay Zheludev, Nanyang Technological University, University of Southampton, Singapore, UK
We report a new imaging concept that — in principle — allows unlimited optical resolution of a limited-size object. The image reconstruction is a reversed process to superoscillatory focusing where a mask can be designed to focus light into subwavelength hotspots of any size and shape.
11:00 - 11:15 - Inverse-designed 3D laser nanoprinted phase plates to extend the depth of field of imaging systems Oral [Show abstract]
  • Thomas Sturges, Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology, Germany
Utilising machine-learning based inverse design, we develop a phase mask that extends the depth of field of a standard microscope by nearly four times. Employing two-photon 3D laser nanoprinting for fabrication, our design provides a significant improvement in imaging depth, as validated by experimental characterisations.
11:15 - 11:45 - Intelligent Meta-Imaging for Underwater, Aerial and Land Invited oral [Show abstract]
  • Din Ping Tsai, City University of Hong Kong, Hong Kong
  • Xiaoyuan Liu, The State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Hong Kong
  • Muku Chen, THE CITY UNIVERSITY OF HONG KONG, Hong Kong
  • Takuo Tanaka, Innovative Photon Manipulation Research Team, RIKEN Center for Advanced Photonics, Japan
We have developed a series of intelligent meta-lens systems for underwater, land, and aerial imaging and sensing. We reported the design, fabrication, characterization, and applications of the monocular, binocular, and multilocular meta-lens.
11:45 - 12:15 - Zero-Energy Sensor Networks with mm-wave Metamaterial Wireless Sensors Invited oral [Show abstract]
  • Filippo Costa, University of Pisa, Italy
  • Simone Genovesi, University of Pisa, Italy
  • Sandra Rodini, University of Pisa, Italy
  • Giuliano Manara, University of Pisa, Italy
The outlook for the impending era of 6G envisions an unparalleled surge in the deployment of Internet of Things (IoT) sensors, expected to reach approximately ten times the quantity present in the 5G era (10 million devices per square kilometer). To deploy such big number of sensors is imperative to meet the requirements of being cost-effective, energyefficient, easily maintainable, and environmentally sustainable. This opens the possibility of massively deploying metamaterials structures with sensing capabilities at zero-energy consumption.
12:15 - 12:30 - Fast-speed Ultrasonic Imaging Using a Single Sensor by Combining Disordered Metasurface and Artificial Intelligence Oral [Show abstract]
  • Wei Wang, Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
  • Jie Hu, Department of Information Science and Technology, Nanjing Forest University, Nanjing, 210037, China
  • Jingjing Liu, Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
  • Bin Liang, Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
  • Johan Christensen, IMDEA Materials Institute, Calle Eric Kandel, 2, 28906, Getafe, Madrid, Spain
  • Jianchun Cheng, Key Laboratory of Modern Acoustics, MOE, Institute of Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
Non-destructive testing and medical diagnostic techniques using ultrasound has become indispensable in evaluating the state of materials or imaging the internal human body, respectively. We propose a mechanism that can realize fast-speed and single-sensor ultrasonic imaging with ultra-low cost using a disordered metasurface combined with a neural network. A single fixed sensor and a handcrafted metasurface with costs of much less than one dollar are proved sufficient to yield a high imaging quality.
10:30 - Radiation manipulation by plasmonic metaoptics

Session chairperson(s): Albert Polman; Cesare Soci

10:30 - 11:00 - Plasmonic Twistronics: Discovery of Plasmonic Skyrmion Bags Extended oral [Show abstract]
  • H. Giessen, University of Stuttgart, Germany
  • J. Schwab, University of Stuttgart, Germany
  • A. Neuhaus, University of Duisburg-Essen, Germany
  • P. Dreher, University of Duisburg-Essen, Germany
  • S. Tsesses, Technion-Israel Institute of Technology, Israel
  • A. Mantha, University of Stuttgart, Germany
  • F. Mangold, University of Stuttgart, Germany
  • B. Frank, University of Stuttgart, Germany
  • G. Bartal, Technion-Israel Institute of Technology, Israel
  • F.-J. Meyer zu Heringdorf, University of Duisburg-Essen, Germany
  • T.J. Davis, University of Stuttgart; University of Duisburg-Essen; University of Melbourne, Germany
Plasmonic skyrmion lattices are created by the interference of surface plasmon polariton waves. Superimposing two plasmonic skyrmion lattices with a relative twist creates a moiré skyrmion superlattice. Their vector fields are calculated numerically and measured using time-resolved PEEM vector microscopy, demonstrating that the topology contains skyrmion bags of controllable size for certain magic angles.
11:00 - 11:15 - Tailoring the Radiation Pattern of Infrared Self-Complementary Nanoantennas With Ultrawide Impedance Bandwidth Oral [Show abstract]
  • Syuzanna Asadulina, School of Physics and Engineering, ITMO University, St. Petersburg, Russia, Russia
  • Stanislav Glybovski, School of Physics and Engineering, ITMO University, St. Petersburg, Russia, Russia
  • Inti Leandro Ruiz Castro, Physics Department, Universidad Nacional de Colombia, Bogota, Colombia, Colombia
  • JUAN BAENA DOMINGO DOELLO, Physics Department, Universidad Nacional de Colombia, Bogota, Colombia, Colombia
A spiral self-complementary plasmonic nanoantenna has been designed to have constant input impedance within a wide frequency range, at least 50 to 300 THz. By covering the antenna with a glass cylinder of variable dimensions, its radiation pattern can be tailored without much effect on the constant input impedance. This approach can facilitate the design of broadly tunable nanoscale antennas that operate efficiently in the infrared region of the electromagnetic spectrum.
11:15 - 11:30 - Angle-resolved Cathodoluminescence Interferometry Of Plasmonic Scatterers Oral [Show abstract]
  • Evelijn Akerboom, AMOLF, Netherlands
  • Albert Polman, AMOLF, Netherlands
High energy electrons can excite resonances in nanostructures that radiate to the far field as cathodoluminescence (CL). Here, we study the sequential interaction of the electron with a plasmonic tip and a metallic surface. These two coherent excitations interfere in the far-field which creates a platform to study cathodoluminescence interferometry.
11:30 - 11:45 - On-Chip Emitter-Coupled Meta-Optics for Versatile Quantum Light Sources Oral [Show abstract]
  • Sören im Sande, University of Southern Denmark, Denmark
  • Yinhui Kan, University of Southern Denmark, Denmark
  • Danylo Komisar, University of Southern Denmark, Denmark
  • Cuo Wu, University of Southern Denmark, Denmark
  • Shailesh Kumar, University of Southern Denmark, Denmark
  • Sergey I. Bozhevolnyi, University of Southern Denmark, Denmark
  • Fei Ding, University of Southern Denmark, Denmark
The advancement of photonic quantum technologies is highly dependent on the development of quantum light sources. We showcase a new metasurface-enabled versatile quantum light sources that enables arbitrary polarization control over multiple channels with distinct directions by exploiting the nonradiative interaction between the quantum emitters with surrounding scattering meta-atoms.
11:45 - 12:00 - Dissipation-Enabled Subradiant Entanglement In Plasmonic Nanocavities Oral [Show abstract]
  • Angus Crookes, University of Birmingham, United Kingdom
  • Ben Yuen, University of Birmingham, United Kingdom
  • Angela Demetriadou, University of Birmingham, United Kingdom
In this work, we demonstrate that in plasmonic nanocavities subradiant entanglement is destroyed due to coupling with multiple even and odd plasmonic modes. To address this, we design a nanocavity with supressed odd modes, enabling robust entanglement generation. Our results open exciting prospects for room temperature entanglement with simple setups.
12:00 - 12:15 - Halting The Dissipation Of Classical And Quantum Light By The Zeno Effect Oral [Show abstract]
  • Anton Vetlugin, Nanyang Technological University, Singapore
  • Mariia Sidorova, Institute of Optical Sensor Systems, Germany
  • Ruixiang Guo, Nanyang Technological University, Singapore
  • Cesare Soci, Nanyang Technological University, Singapore
  • Nikolay Zheludev, University of Southampton, United Kingdom
We experimentally demonstrate that the dissipation rate of light propagating in an intricate optical network can be reduced tremendously by increasing the number of absorbers.
12:15 - 12:30 - Single Photon Source with High-Purity Linearly Polarized Vortex Beam Oral [Show abstract]
  • Xujing Liu, University of Southern Denmark, Denmark
  • Yinhui Kan, University of Southern Denmark, Denmark
  • Shailesh Kumar, University of Southern Denmark, Denmark
  • Fei Ding, University of Southern Denmark, Denmark
  • Sergey Bozhevolnyi , University of Southern Denmark, Denmark
We propose an ultracompact single photon source of linearly polarized vortex beams based on chip-integrated quantum emitter-coupled metasurfaces. We experimentally demonstrate on-chip single-photon generation of high-purity linearly polarized vortex beams with prescribed topological charges of 0, -1, and +1.
12:30 - 14:00 - Lunch Break (Wednesday)
14:00 - 15:30 - Oral Sessions (Wednesday Afternoon 1)
14:00 - Wave phenomena at temporal interfaces

Session chairperson(s): Davide Ramaccia; Emanuele Galiffi

14:00 - 14:30 - Time-switched metastructures: analysis and design of the anomalous radiative phenomena at time-interfaces Invited oral [Show abstract]
  • Davide Ramaccia, RomaTre University , Italy
  • Luca Stefanini, RomaTre University , Italy
  • Alessio Monti, RomaTre University , Italy
  • Mirko Barbuto, Niccolò Cusano University, Italy
  • Stefano Vellucci, Niccolò Cusano University, Italy
  • Michela Longhi, Niccolò Cusano University, Italy
  • Mohsen Karamirad, RomaTre University, Italy
  • Alessandro Toscano, RomaTre University, Italy
  • Andrea Alù, Advanced Science Research Center - Photonics Initiative, New York (USA)
  • Vincenzo Galdi, University of Sannio, Italy
  • Filiberto Bilotti, RomaTre University, Italy
In the last few years, the temporal counterpart of spatial interfaces, named temporal interfaces, has been deeply investigated to model, validate, and exploit several novel anomalous wave phenomena in time-domain. Reflection and transmission, accompanied by frequency conversion, always take place at a temporal interface between two different unbounded media, but, recently, temporal interfaces triggered by the effective media parameters experienced by guided waves have been proposed. In this contribution, the recent findings on boundary-induced temporal interfaces are presented, considering two different guiding structures capable to radiate a continuous spatio-temporal spectrum in different directions and a highly confined beam radiated in end-fire direction, respectively.
14:30 - 15:00 - Energy and frequency manipulation with temporal interfaces Invited oral [Show abstract]
  • Emanuele Galiffi, Advanced Science Research Center, Graduate Center, CUNY, USA
  • Shixiong Yin, Advanced Science Research Center, Graduate Center, CUNY, USA
  • Diego M Solis, Universidad de Extremadura, Spain
  • NIkita Nefedkin, Advanced Science Research Center, Graduate Center, CUNY, USA
  • Anthony Harwood, Imperial College London, UK
  • Stefano Vezzoli, Imperial College London, UK
  • Riccardo Sapienza, Imperial College London, UK
  • Nader Engheta, University of Pennsylvania, USA
  • Andrea Alu, Advanced Science Research Center, Graduate Center, CUNY, USA
We discuss the role of temporal interfaces to achieve photonic time-reflections, and leverage them to realize and control the interaction between broadband pulses, thereby realizing the analogue of mechanical collisions for photons. In our analysis, we also discuss the need for generalized boundary conditions for time-interfaces, and explore intriguing phenomena arising in the quantum limit. Our results shed new insights on the use of temporal metamaterials to control the energy and frequency of electromagnetic waves, and to engineer exotic quantum states of light.
15:00 - 15:30 - Radiation Dynamics by Temporal Switching in General Dispersive Optical Waveguides Invited oral [Show abstract]
  • Amir Shlivinski, Ben Gurion University of the Negev, Israel
  • Yakir Hadad, Tel-Aviv University, Israel
We analytically and numerically explore the characteristics of the radiation caused by abrupt and soft temporal switching of an electromagnetic open dispersive and lossy optical waveguide embedded in vacuum.
14:00 - Scattering in active systems

Session chairperson(s): Alexander K. Stoychev; Michael Haberman

14:00 - 14:30 - Superradiant Scattering at Coupled Policeman Whistle Meta-Atoms Extended oral [Show abstract]
  • Alexander K. Stoychev, ETH Zurich, Switzerland
  • Xinxin Guo, ETH Zurich, Switzerland
  • Ulrich Kuhl, ETH Zurich; Université Côte d’Azur, Switzerland; France
  • Nicolas Noiray, ETH Zurich, Switzerland
This study introduces an aeroacoustic meta-atom based on a toy policeman whistle and investigates its scattering properties. The first part of the manuscript examines the nonlinear scattering at a single atom, while the second explores the effects of coupling pair of them.
14:30 - 15:00 - Acoustic Wave Scattering from Spatiotemporally Modulated Cylindrical Domains Invited oral [Show abstract]
  • Benjamin M. Goldsberry, Applied Research Laboratories, UT Austin, USA
  • Samuel P. Wallen, Applied Research Laboratories, UT Austin, USA
  • Michael R. Haberman, The University of Texas at Austin, USA
Investigation of acoustic scattering from a two-dimensional annular fluid inhomogeneity with a spatiotemporally modulated compressibility. Computations of the far field directivity pattern are carried out as a function of the modulation parameters to show a large degree of control over the scattered field directivity and frequency content.
15:00 - 15:15 - An airborne acoustic circulator based on time-modulated active control Oral [Show abstract]
  • Matthieu Malléjac, LWE - EPFL, Switzerland
  • Romain Fleury, LWE - EPFL, Switzerland
We design and experimentally demonstrate a non-reciprocal three-port acoustic scatterer that behaves as a circulator for audible sound, by actively modulating in time the effective mass of acoustic membranes. We discuss the design and experimental validation of such acoustic circulator, implemented with actively controlled loudspeakers, in the realm of audible and airborne acoustics.
15:15 - 15:30 - Moving Objects In Diverse Media Through Wave Momentum Manipulation Oral [Show abstract]
  • Bakhtiyar Orazbayev, Nazarbayev University, Kazakhstan
  • Matthieu Malléjac, École polytechnique fédérale de Lausanne (EPFL), Switzerland
  • Nicolas Bachelard, Université de Bordeaux, France
  • Stefan Rotter, Vienna University of Technology (TU Wien), Austria
  • Romain Fleury, École polytechnique fédérale de Lausanne (EPFL), Switzerland
In this paper, we experimentally demonstrate the ability to move an object in disordered and dynamic media by using acoustic waves for transferring linear or angular momentum to the object. In contrast to the remarkable results that have been achieved in optical or acoustical tweezers, our approach overcomes the strict requirements for the environment, such as a tightly controlled environment with minimal reverberation and static conditions. Furthermore, we demonstrate that knowledge of the physical attributes of objects or the composition of the surrounding medium is not needed. Instead, we acquire scattering information and the position of the object to adjust the incident wavefronts iteratively as it moves and operates only from the far field. Finally, we demonstrate the method's robustness to substantial alterations in the scattering medium.
14:00 - Tunable and reconfigurable optical metastructures

Session chairperson(s): Giulia Tagliabue; Odysseas Tsilipakos

14:00 - 14:15 - Non-volatile Chalcogenide Nano-opto-mechanical Metasurface Oral [Show abstract]
  • Ding Li, University of Southampton, United Kingdom
  • Abbas Sheikh Ansari, University of Alberta, Canada
  • Kwanghyun Kim, University of Alberta, Canada
  • Behrad Gholipour, University of Alberta, Canada
  • Jun-Yu Ou, University of Southampton, UK
<p> We present chalcogenide nano-optomechanical metasurfaces enabling non-volatile switching between crystalline and amorphous states, significantly altering optical and mechanical properties, suitable for optical neural networks, memory, and computing.</p>
14:15 - 14:30 - Nonvolatile Light Modulation in a Tunable Memristor Device Oral [Show abstract]
  • Alexander Korneluk, University of Warsaw, Poland
  • Tomasz Stefaniuk, University of Warsaw, Poland
We present experimental results on the development of nanoionic device capable of maintaining multiple optical states in a nonvolatile manner - an optical memristor. Switching between different optical states is achieved by applying an external voltage to a dielectric film with embedded conductive filaments. We support our findings with ellipsometric measurements.
14:30 - 15:00 - Thermo-optical Effects in Nanoantennas and Metasurfaces Invited oral [Show abstract]
  • Giulia Tagliabue, LNET - IGM - STI - EPFL, Switzerland
Photo-induced thermo-optical effects in dielectric nanoresonators enable contactless modulation of their optical response. We report modelling and experimental results on the use of these effects for reconfigurable metasurfaces.
15:00 - 15:15 - Optical Metasurfaces and Piezoelectric MEMS - a Versatile Platform for Tunable Optics Oral [Show abstract]
  • Paul Thrane, SINTEF Smart Sensors and Microsystems, Norway
  • Christopher Dirdal, SINTEF Smart Sensors and Microsystems, Norway
  • Firehun Dullo, SINTEF Smart Sensors and Microsystems, Norway
  • Runar Dahl-Hansen, SINTEF Smart Sensors and Microsystems, Norway
  • Chao Meng, University of Southern Denmark, Denmark
  • Yadong Deng, University of Southern Denmark, Denmark
  • Chuanshuo Wang, University of Southern Denmark, Denmark
  • Haonan Li, University of Southern Denmark, Denmark
  • Yinhui Kan, University of Southern Denmark, Denmark
  • Fei Ding, University of Southern Denmark, Denmark
  • Sergey Bozhevolnyi, University of Southern Denmark, Denmark
We present an overview of a series of tunable optical components based on combining optical metasurfaces with piezoelectric Micro-Electromechanical Systems (MEMS), including a tunable lens, dynamic waveplate, switchable polarizer and orbital angular momentum generation. We cover the theory of operation, results, as well as our experiences in fabricating and using the devices. In general, our approach seems promising for applications requiring ultra-low power switching between several different functions on frequencies up to tens of kHz and with millimeter sized apertures.
15:15 - 15:30 - Polymeric Optical Metasurfaces by Two-Photon Lithography: Practical Designs for Beam Steering Oral [Show abstract]
  • Odysseas Tsilipakos, National Hellenic Research Foundation, Greece
  • George Perrakis, Foundation for Research and Technology Hellas, Greece
  • Maria Farsari, Foundation for Research and Technology Hellas, Greece
  • Maria Kafesaki, Foundation for Research and Technology Hellas, Greece
We study polymeric optical metasurfaces for beam steering to be fabricated with two-photon lithography. We start from idealized meta-atom shapes and proceed to smooth half-ellipsoid-like structures that are compatible with the voxels of the writing process. Our work aspires to enable high-performance, practical metasurfaces taking fabrication limitations thoroughly into account.
14:00 - Optical and near-IR metasurfaces: experimental studies

Session chairperson(s): Marco Piccardo; Jacob Scheuer

14:00 - 14:30 - Robust Meta-Optics For High-Power Laser Beam Shaping From Near-UV To Near-IR Invited oral [Show abstract]
  • Maria Beatriz Silva Oliveira, Department of Physics, Instituto Superior Técnico, Universidade de Lisboa, Portugal
  • Ines da Silva Gonçalves, Department of Physics, Instituto Superior Técnico, Universidade de Lisboa, Portugal
  • Pablo San Miguel Claveria, GoLP/Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Técnico, Universidade de Lisboa, Portugal
  • Patricia Estrela, GoLP/Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Técnico, Universidade de Lisboa, Portugal
  • Pedro Araujo, Instituto de Engenharia de Sistemas e Computadores—Microsistemas e Nanotecnologias (INESC MN), Portugal
  • Marta Fajardo, GoLP/Instituto de Plasmas e Fusao Nuclear-Laboratorio Associado, Instituto Superior Técnico, Universidade de Lisboa, Portugal
  • Marco Piccardo, Department of Physics, Instituto Superior Técnico, Universidade de Lisboa, Portugal
We demonstrate monolithic fused silica metasurfaces enabling high-power laser beam shaping, offering robustness and unprecedented control at the single nanopillar level. They withstand extreme power densities, promising advancements in high-power structured laser-matter interactions.
14:30 - 15:00 - Amplifying and Reshaping PL from Quantum Wells with Plasmonic Metasurfaces Invited oral [Show abstract]
  • Jacob Scheuer, Tel Aviv Univrsity, Israel
  • Tamar Haimov, Tel Aviv Univrsity, Israel
  • Iddo Tsur, Tel Aviv Univrsity, Israel
We present a theoretical and experimental study of photoluminescence enhancement from QWs and spectral reshaping, by coupling to plasmonic metasurfaces. The model facilitates spectral emission design and reveals the significance of the metasurface geometry.
15:00 - 15:15 - Tunable near-infrared edge-enhanced meta-scope Oral [Show abstract]
  • Jun-Yu (Bruce) Ou, University of Southampton, United Kingdom
  • Chuang Sun, University of Southampton, United Kingdom
  • Hailong Pi, University of Southampton, United Kingdom
  • Kian Shen Kiang, University of Southampton, United Kingdom
  • Jize Yan, University of Southampton, United Kingdom
Edge detection as the first step of image segmentation and classification is essential for most computer vision systems and is generally realized via digital algorithms, which require high computational resources and energy consumption. To reduce energy consumption, all-optics analog systems have been attracting much attention because of their fast processing speed and low energy requirement. Here, we demonstrated a compact dual-mode meta-scope working at near-infrared to achieve an all-optics analogy edge-enhancement system with a 0.7λ resolution and 58X magnification using engineered metalens. Our results could open new opportunities in biomedical imaging applications, industrial machine vision, and semiconductor inspection.
15:15 - 15:30 - Colloidal Self-Assembly of Silver Nanoparticle Clusters for Optical Metasurfaces Oral [Show abstract]
  • Maeva Lafitte, University of Bordeaux - CNRS, France
  • Ranjeet Dwivedi, Ensemble3 Centre of Excellence Varsaw, Poland
  • Rajam Elancheliyan, University of Strasbourg - CNRS, France
  • Alexandre Baron, University of Bordeaux - CNRS, France
  • Virginie Ponsinet, University of Bordeaux - CNRS, France
  • Lionel Buisson, University of Bordeaux - CNRS, France
  • Francois Lagugne-Labarthet, Western University, Canada
  • Philippe Barois, University of Bordeaux - CNRS, France
  • Isabelle Ly, University of Bordeaux - CNRS, France
  • Olivier Mondain-Monval, University of Bordeaux - CNRS, France
We show that an emulsion-based formulation approach can be used to produce optical metasurfaces made of a layer of optical resonators composed of an assembly of metallic nanoparticles (NPs). We describe the formulation procedure and the optical techniques that were used to produce and characterize the properties of the individual resonators and of the final optical metasurfaces. Doing so, we evidence the strong optical magnetism exhibited by the resonators and the intense interaction of the clusters layer with an incoming plane wave. Our approach opens the way to the realization of large scale metasurfaces.
14:00 - Novel physical phenomena in plasmonic systems

Session chairperson(s): Juan Domingo Baena Doello; Fadil Iyikanat

14:00 - 14:15 - Ballistic vs. diffusive transport in metals Oral [Show abstract]
  • Yonatan Sivan, Ben-Gurion University, Israel
We show that ballistic transport of electrons in metals is weaker than diffusive transport because the femtosecond-scale collision rates of the non-thermal electrons makes their mean-free-path negligible. Our predictions are correlated with various experimental examples, and open the way to easy modelling of non-thermal electron distributions in arbitrarily-complex metal nanostructures.
14:15 - 14:30 - Exploring Surface Roughness in Epsilon-Near-Zero Materials Oral [Show abstract]
  • David Navajas, Public University of Navarre, Spain
  • José M. Pérez-Escudero, Public University of Navarre, Spain
  • Iñigo Liberal, Public University of Navarre, Spain
The practical application of materials with epsilon-near-zero (ENZ) characteristics heavily depends on the quality of real-world ENZ materials, considering factors like material losses and surface roughness. These materials have drawn interest due to their strong nonlinear responses and unique behavior. In this study, an experimental examination of how surface roughness affects ENZ substrates is presented. We employed silicon carbide (SiC) substrates deliberately engineered to exhibit different levels of roughness, enabling us to analyze samples spanning from a few to hundreds of nanometers in size scales. Substrates with nanoscale roughness experience adverse effects due to longitudinal phonon coupling and strong ENZ fields, while at larger roughness scales, the ENZ band demonstrates to be more robust compared to dielectric and surface phonon polariton (SPhP) bands.
14:30 - 15:00 - Review of Potential Applications of Self-Complementary Plasmonic Metasurfaces Invited oral [Show abstract]
  • Juan D. Baena, Universidad Nacional de Colombia, Colombia
  • Syuzanna Asadulina, ITMO University, Russia
  • Inti L. Ruiz, Universidad Nacional de Colombia, Colombia
  • Juan P. del Risco, Universidad Nacional de Colombia, Colombia
  • Julián D. Ortiz, Universidad de San Buenaventura, Colombia
Interesting phenomena and applications of self-complementary metasurfaces have been studied in microwaves and sub-THz ranges like filtering [1], polarizing [2-4], light deflecting [5], guiding of surface waves [6, 7], and guiding of line waves [8-10]. All these applications were based on Babinet’s principle. However, it is rather a challenging task to scale down those structures to make them properly work in the infrared, because Babinet’s principle is violated in general due to the poor condutivity of metals in infrared. Fortunately, it was theoretically and numerically demonstrated in [11] that it is still possible to recover the validity of this principle by making metasurfaces from silicon and silver with a thickness about 13 nm. The goal of this work is to demonstrate that all the applications of self-complementary metasurface found in microwaves and sub-THz can be also extended to infrared.
15:00 - 15:30 - Ultrafast Processes in 2D Materials and Polariton-Enhanced Nonlinear Optical Response Invited oral [Show abstract]
  • Fadil Iyikanat, ICFO-Institut de Ciencies Fotoniques, Spain
  • Javier García de Abajo, ICFO-Institut de Ciencies Fotoniques, Spain
<p> Nonlinear optical processes arising from the interaction of light with matter enable precise spectral control of light with potential application in all-optical devices. In this study, we use first-principles calculations to explore the polariton-induced linear and nonlinear optical responses of various 2D materials across a broad spectral range extending from the mid-infrared to the visible domain. Our findings indicate an extraordinarily large nonlinear optical response in these materials, which can be attributed to enhanced quantum effects&nbsp; associated with the reduction in dimensionality. This research line aims to enable a range of potential applications, including harmonic generation, optical modulation, and quantum information processing.</p>
15:30 - 16:00 - Coffee Break (Wednesday Afternoon)
16:00 - 17:30 - Oral Sessions (Wednesday Afternoon 2)
16:00 - Unconventional time-modulation schemes and media

Session chairperson(s): Yonatan Sivan; Sajjad Taravati

16:00 - 16:30 - Single cycle optical nonlinearity of transparent conducting oxides Invited oral [Show abstract]
  • Yonatan Sivan, Ben-Gurion University, Israel
We provide the first ever rigorous theoretical study of Drude metals and transparent conducting oxides illuminated by an intense single cycle optical pulse. We show the dominance of coherences in photon-electron interactions and the inability to reach population inversion.
16:30 - 16:45 - Nonlinear Variation in Permeability Towards Time-varying Metamaterials Oral [Show abstract]
  • Toshiyuki Kodama, Tohoku university, Japan
  • Nobuaki Kikuchi, Tohoku university, Japan
  • Satoshi Okamoto, Tohoku university, Japan
  • Seigo Ohno, Tohoku university, Japan
  • Satoshi Tomita, Tohoku university, Japan
Permeability variation of a lithographically-prepared magnetic metamaterials is studied by means of spin torque ferromagnetic resonance. We demonstrate that only the real or imaginary part of the relative permeability can be modified by precisely setting the bias current and the external magnetic field.
16:45 - 17:00 - Realizing Effective Axion Fields in Time-Varying Media Oral [Show abstract]
  • Leon Shaposhnikov, ITMO University, Russia
  • Eduardo Barredo-Alamilla, ITMO University, Russia
  • Frank Wilczek, Massachusetts Institute of Technology, USA
  • Maxim Gorlach, ITMO University, Russia
Electrodynamics of time-varying media has recently attracted great attention promising strong optical nonreciprocity and efficient frequency conversion. Here, we predict that a uniform gyrotropic medium with the magnetization periodically varied in time enables an effective dynamic axion field which uncovers interesting optical properties.
17:00 - 17:15 - Control of Water Waves Using Time-varying Vertical Plates Oral [Show abstract]
  • Magdalini Koukouraki, Sorbonne Université, France
  • Philippe Petitjeans, ESPCI, France
  • Agnès Maurel, ESPCI, France
  • Vincent Pagneux, Le Mans Université, France
We study theoretically and experimentally the propagation of water waves over a time-varying topography, using thin vertical plates as metamaterials. Starting with the scattering problem of a plane wave incident on a vertical submerged plate inside a water channel, we extract the scattering coefficients as a function of the frequency and the plate height. We then report on harmonic generation, an effect which is observed experimentally when the plate height is a function of time. Finally, we extend the study to the case of a periodic array of plates and investigate both analytically and numerically the two-dimensional propagation of shallow water waves over a time-varying medium, which switches from isotropic to anisotropic at a given time.
17:15 - 17:30 - One-Way Absorption and Isolation in Space-Time-Periodic Superconducting Metasurfaces Oral [Show abstract]
  • Sajjad Taravati, University of Southampton, United Kingdom
We explore the unique characteristics, analytical methods, and properties of these superconducting metasurfaces, demonstrating their unprecedented capabilities in manipulating electromagnetic waves. Our findings highlight the potential of spatiotemporal superconducting surfaces in enhancing quantum computing, communication systems, and beyond. This research not only paves the way for novel applications of superconductors but also opens up new avenues in the design and development of advanced metasurfaces for wavecrafting.
16:00 - Reconfigurable scattering

Session chairperson(s): Steven Anlage; Anthony Grbic

16:00 - 16:30 - Exploring Non-Hermitian Scattering Singularities in Complex Systems By Means of Tunable Metasurfaces Invited oral [Show abstract]
  • Jared Erb, University of Maryland, USA
  • Isabella Giovannelli, University of Maryland, USA
  • Nadav Shaibe, University of Maryland, USA
  • Steven Anlage, University of Maryland, USA
We utilize continuously tunable metasurfaces in complex enclosures to create, manipulate, and destroy scattering singularities in great abundance, enabling discovery of new topological properties and moving one step closer to control of arbitrary scattering systems.
16:30 - 16:45 - Spatiotemporal Wood's Anomaly in Folded Time Gratings: Theory and Experiment Oral [Show abstract]
  • Amit Shaham, Technion - Israel Institute of Technology, Israel
  • Ben-Zion Joselson, Technion - Israel Institute of Technology, Israel
  • Ilya Varenisov, Technion - Israel Institute of Technology, Israel
  • Denis Dikarov, Technion - Israel Institute of Technology, Israel
  • Ariel Epstein, Technion - Israel Institute of Technology, Israel
Proposing and studying a emph{compact} setup, we experimentally observe spatiotemporal Wood's anomaly: a emph{single} waveguide-enclosed strip loaded with a time-modulated capacitor features a dynamic resonance closely related to the structural cutoff. Beyond this fundamental demonstration, our platform will facilitate low-power transmissive time-modulated devices.
16:45 - 17:00 - Electromagnetic Scattering at an Arbitrarily Accelerated Interface Oral [Show abstract]
  • Klaas De Kinder, KU Leuven, Belgium
  • Christophe Caloz, KU Leuven, Belgium
We present a general analytical solution to the problem of electromagnetic scattering at a one-dimensional arbitrarily accelerated space-time engineered-modulation (ASTEM) interface in the subluminal regime. We show that such an interface fundamentally produces chirping, whose profile can be designed according to specifications. This work represents an important step in the development of ASTEM crystals and holds significant potential for applications in microwave and optical devices reliant on chirp-based functionalities.
17:00 - 17:15 - Metaradar − Time Synchronized Metasurface Tranceivers Oral [Show abstract]
  • Gangil Byun, UNIST, Korea (South)
  • Anthony Grbic, University of Michigan, United States
  • Thai Bao Hoang, UNIST, South Korea
This paper presents the concept of a Metaradar, which utilizes time-synchronized metasurfaces for modulating and demodulating temporal frequencies. Each unit cell features a rectangular patch that interacts with free-space electromagnetic waves and is connected to a phase shifter. The phase shifter is implemented as a hybrid coupler loaded with two
17:15 - 17:30 - Reconfigurable soft acoustic flat metalens Oral [Show abstract]
  • Simon Colanges, University of Bordeaux, France
  • Arthur Lamouroux, University of Bordeaux, France
  • Cédric Le Coz, University of Bordeaux, France
  • Etienne Grau, University of Bordeaux, France
  • Thomas Vidil, University of Bordeaux, France
  • Henri Cramail, University of Bordeaux, France
  • Thomas Brunet, University of Bordeaux, France
  • Olivier Mondain-Monval, University of Bordeaux, France
The purpose of this project concerns the development of new reconfigurable, self-healing and recyclable materials for acoustics. In earlier studies it was shown that soft porous polymer materials (i.e. with a glass transition temperature much smaller than room temperature) exhibit an acoustic velocity that strongly depend on the materials porosity value. Using this property, gradient-index acoustic lenses were obtained by spatially assembling pieces of materials with different porosity values. In this study, we now aim at locally changing the value of the acoustic velocity by controlling the crosslinking of the soft porous polymer matrix through the application of a UV stimulus of tuneable intensity. To do so, we grafted some UV-sensitive chemical functions (namely cinnamoyl groups) onto different polymer backbones and measured the evolution of the mechanical properties as a function of the UV illumination time. Our results show that the materials mechanical properties can be significantly changed by the application of this stimulus. We present and discuss some results obtained with one backbone polymer chain, namely polydimethylsiloxane. The obtained results confirm the validity of our approach and opens the way to soft reconfigurable acoustic devices.
16:00 - Complex effects in metamaterials

Session chairperson(s): Raphael Kastner; Amir Jafargholi

16:00 - 16:15 - 3D dispersion measurement of metamaterial Oral [Show abstract]
  • Eugene Koreshin, ITMO University, Russia
  • Denis Sakhno, ITMO University, Russia
  • Pavel Belov, ITMO University , Russia
This study presents the approach of extraction three-dimensional dispersion from in-plane near-field measurements. The metamaterial based on orthogonal sets of wires was studied in microwave range. The hyperbolic isofrequency contours of double wire medium was confirmed.
16:15 - 16:30 - Polarization Inversion in PTD - Symmetric Electromagnetic Systems Oral [Show abstract]
  • Roee Geva, Tel Aviv University, Israel
  • Màrio Silveirinha, University of Lisbon and Instituto de Telecomunicações, Portugal
  • Raphael Kastner, Tel Aviv University, Israel
Definitions of incident and reflected modes in the PTD formulation result in co-polarized non-reflection for 45^0 and 135^0 polarizations with respect to the mirror plane. For other incident polarizations, the non-reflection angle is rotated and reflections are inverted. A number of applications is envisioned, in particular as reflective polarizers.
16:30 - 16:45 - Tuning the forward scattering of magneto-optical particles by complex-frequency incident fields Oral [Show abstract]
  • Evangelos Almpanis, National and Kapodistrian University of Athens, Greece
  • Iridanos Loulas, National and Kapodistrian University of Athens, Greece
  • Grigorios Zouros, National and Kapodistrian University of Athens, Greece
  • Kosmas Tsakmakidis, National and Kapodistrian University of Athens, Greece
The so-called oblique Kerker effect is a novel phenomenon in which directional scattering of light can occur at an arbitrary angle, controlled by the scatterer's anisotropy. In this work, we study the oblique Kerker scattering in magneto-optical rods that exhibit optical anisotropy due to an external magnetic field. We found that, for a given external magnetization, the anisotropy can be further tuned at will, using complex frequency excitations, in the frame of an induced anisotropic virtual gain. This approach allows for controlling the scattering angle by changing the shape of the incident radiation, rather than altering the medium itself or the external magnetic field. Our analysis generalizes the Kerker conditions for multipolar-mode overlap in the presence of optical anisotropy and shows the mechanisms that control the angle at which destructive interference occurs. This approach introduces a significant advancement in the active steering of scattering by particles, providing unprecedented control over light manipulation in photonic applications.
16:45 - 17:00 - GPS Interference Cancellation Using Magneto-dielectric Metamaterials Oral [Show abstract]
  • Amir Jafargholi, EPFL, Switzerland
This paper introduces a novel method and structure designed to mitigate unwanted interference at the antenna in conventional Global Positioning System (GPS) applications. In contrast to traditional approaches that typically utilize high-impedance structures with limited cancellation or antenna arrays employing null-steering techniques, which often result in increased complexity and cost, this study proposes the use of a single-element circularly polarized truncated microstrip patch antenna radially loaded by a magneto-dielectric metamaterial (MTM) structure. The problem is analytically examined, and an appropriate meta cell is chosen, designed, and fabricated. The proposed MTM cover features a cylindrical shape with a thickness and height of 0.02
17:00 - 17:15 - Easy Manufactured Conformable Artificial Magnetic Conductor Oral [Show abstract]
  • Chloé Scotti, CEA DAM, France
  • Stefan Enoch, CNRS, Institut Fresnel, Aix-Marseille University, France
  • Nicolas Malléjac, CEA DAM, France
An Artificial Magnetic Conductor has been designed and realized using a metasurface made by assembling different simple and cheap parts easily supplied. The method described allows us to tune the resonant frequency of the metasurface in a simple way so it can be used in the frequency band of interest at 2-17GHz.
17:15 - 17:30 - Predator-Prey Nonreciprocal Interactions of Toroidal Charge-Current Configurations Oral [Show abstract]
  • Chaitanya K. Mididoddi , University of Southampton, United Kingdom
  • Nikitas Papasimakis, University of Southampton, United Kingdom
  • Nikolay I. Zheludev, University of Southampton & Nanyang Technological University, United Kingdom & Singapore
In 2001, G. N. Afanasiev predicted that electromagnetic interactions between toroidal charge-current configurations can be nonreciprocal. Here, we show that interacting toroidal coils of different orders break the Newtonian action-reaction equality without breaking Lorentz reciprocity. Such interactions between toroidal charge-current configurations resemble the predator-prey behavior in living systems and chemical kinetics and can underpin the recently identified mechanism of the mobilization phase transition to the new state of matter, the time crystal.
16:00 - Dielectric metasurfaces: experimental studies

Session chairperson(s): Uriel Levy; Natalia Litchinitser

16:00 - 16:30 - Advanced topics in dielectric metasurfaces Invited oral [Show abstract]
  • Uriel Levy, HUJI, Israel
We present our recent work related to dielectric metasurfaces. This includes new materials platforms such as silicon rich silicon nitride demonstrating an important interplay between real and imaginary parts of the refractive index, and lithium niobate for obtaining tunability. Advanced imaging with metalenses is also demonstrated. Finally, novel structures for resonances are presented and applications are discussed.
16:30 - 17:00 - Structured Freestanding Nano-/Micro- Membrane as a New Platform of Meta-Optics Invited oral [Show abstract]
  • Kuniaki Konishi, The University of Tokyo, Japan
This presentation explores freestanding thin film structures with nano or micro hole arrays, like photonic crystal nanomembranes, which demonstrate circular polarized third harmonic generation in vacuum ultraviolet region and Terahertz membrane metalenses fabricated only by femtosecond laser processing. These advances show the potential for structured freestanding membranes to become a new light-controlling platform.
17:00 - 17:30 - Experimental Validation of Machine Learning-Based Mie-Tronics Invited oral [Show abstract]
  • Natalia Litchinitser, Duke University , United States
  • Hooman Barati Sedeh, Duke University , United States
  • Renee George, Duke University , United States
  • Fangxing Lai , Harbin Institute of Technology Shenzhen, China
  • Hao Li , Harbin Institute of Technology Shenzhen, China
  • Wenhao Li, Duke University , United States
  • Yuruo Zheng, Duke University , United States
  • Dmitrii Tsvetkov, Duke University, United States
  • Shumin Xiao, Harbin Institute of Technology Shenzhen, United States
  • Jingbo Sun, Tsinghua University, China
  • Jiannan Gao, Duke University, United States
We report an experimental validation of a machine learning-based design method that significantly accelerates the development of all-dielectric complex-shaped meta-atoms supporting specified Mie-type resonances at the desired wavelength, circumventing the conventional time-consuming approaches.
16:00 - Emerging concepts in quantum information

Session chairperson(s): Vincenzo Galdi; GIUSEPPE STRANGI

16:00 - 16:30 - Some Emerging Concepts in the Design of Space-Time-Coding Digital Metasurfaces Invited oral [Show abstract]
  • Lei Zhang, Southeast University, China
  • Marco Rossi, University of Sannio, Italy
  • Xiao Qing Chen, Southeast University, China
  • Giuseppe Castaldi, University of Sannio, Italy
  • Tie Jun Cui, Southeast University, China
  • Vincenzo Galdi, University of Sannio, Italy
Space-time-coding digital metasurfaces have established themselves among the most powerful and versatile technological platforms for harnessing spatio-temporal modulations in artificial materials. Here, we review some emerging concepts in their design, with special emphasis on nonuniform modulation and machine-learning approaches. Potential application domains include low-observability and harmonic beam steering/shaping.
16:30 - 17:00 - Exploring Fano Resonances via Thin Film Photonics Invited oral [Show abstract]
  • Giuseppe Strangi, Case Western Reserve University, USA
In this presentation, I will focus into how thin film photonics harnesses the potential of Fano resonances. By layering metal-dielectric thin films, we can create a distinct type of optical coating that exhibits photonic Fano resonance, referred to as a Fano-resonant optical coating (FROC).
17:00 - 17:30 - Information Metamaterials and Quantum-Inspired Information Metamaterials Withdrawn [Show abstract]
  • Jian Wei You, Southeast University, China
  • Tie Jun Cui, Southeast University, China
Information metamaterial is a fusion of electromagnetic (EM) metamaterial with digital information, which can simultaneously manipulate the EM waves and modulate digital information, bridging the EM physical world and digital world. Here, we firstly introduce the concepts and principles of information metamaterials, and then present the cutting-edge research recently conducted by our team on quantum-inspired information metamaterials. In particular, we focus on the advancements in topological information metamaterials and analog quantum information metamaterials, which exhibit exceptional capabilities in manipulating the EM waves, offering new prospects for extending the information metamaterials to the realm of topological and quantum information science.
17:30 - 18:30 - Plenary Session V
17:30 - Plenary Session V

Session chairperson(s): Yakir Hadad

17:30 - 18:30 - Spontaneous Parametric Down-Conversion in Metasurfaces and Other 'Flat' Platforms Plenary [Show abstract]
  • Maria Chekhova, Max-Planck Institute for the Science of Light, Germany
Put your abstract here
18:30 - 19:30 - Break before Social Dinner
19:30 - 22:00 - Social Dinner
12 September 2024 / Start time: 9 h 0 min
09:00 - 10:00 - Plenary Session VI
09:00 - Plenary Session VI

Session chairperson(s): Romain Fleury

09:00 - 10:00 - Structuring Light with Metamaterials Plenary
  • Nader Engheta, The University of Pennsylvania, USA
10:00 - 10:30 - Coffee Break (Thursday Morning)
10:30 - 12:30 - Oral Sessions (Thursday Morning)
10:30 - Nonlinear and tunable structures

Session chairperson(s): Said R. K. Rodriguez; Alex Schuchinsky

10:30 - 11:00 - Exceptional Points of Degeneracy in Nonlinear Systems: Two Coupled Oscillators and Arrays of Oscillators Invited oral [Show abstract]
  • Alireza Nikzamir, Department of Electrical Engineering and Computer Science, University of California, Irvine, USA
  • Kasra Rouhi, Department of Electrical Engineering and Computer Science, University of California, Irvine, USA
  • Filippo Capolino, Department of Electrical Engineering and Computer Science, University of California, Irvine, USA
We discuss the effect of nonlinearities in two systems with an exceptional point of degeneracy (EPD). First, we discuss an oscillator scheme employing coupled resonators with loss and nonlinear gain to achieve ultra-sensitivity of the oscillation frequency to perturbations. Second, we incorporate discrete distributed nonlinear gain and radiating elements within a periodically loaded waveguide, improving radiating power efficiency.
11:00 - 11:30 - Electrothermal Nonlinearities in Contacts of Rough Conductors Invited oral [Show abstract]
  • Alex Schuchinsky, University of Liverpool, United Kingdom
Contact joints of conductors with rough surfaces exhibit nonlinear behaviour. Electrothermal effect is studied in this work. The time evolution of the contact temperature and resistance are evaluated when asperities, shaped as the frustum of cones, are compressed against each other.
11:30 - 11:45 - Kramers-Kronig Relations for Nonlinear Optical Materials and Metamaterials: New Sum Rules for Harmonic Generation Oral [Show abstract]
  • Theodoros Koutserimpas, Cornell University, USA
  • Hao Li, Yale University, USA
  • Owen Miller, Yale University, USA
  • Francesco Monticone, Cornell University, USA
In this talk, we discuss the application of Kramers-Kronig-like relations for harmonic generation. From these integral relations, rooted in causality, and quantum-mechanical basis functions, we derive new sum rules for the second harmonic generation process. We also discuss an alternative quantum mechanical derivation, their application to two- and three-level systems, and their connection to the empirical Miller's rule.
11:45 - 12:15 - Spontaneous Symmetry Breaking in Diffraction Invited oral [Show abstract]
  • Said R. K. Rodriguez, AMOLF, Netherlands
We demonstrate spontaneous symmetry breaking in diffraction. Probing a nonlinear grating with a continuous wave laser, we observe asymmetric diffraction even when the grating and illumination are symmetric. Our analysis reveals how diffracted waves can spontaneously acquire momentum parallel to the lattice vector in quantities unconstrained by the periodicity.
12:15 - 12:30 - Mechanically Tunable Interlaced Wire Medium Oral [Show abstract]
  • Denis Sakhno, ITMO University, Russia
The double interlaced wire metamaterial consists of two identical three-dimensional networks inserted into one another and shifted by half of the period. In this work we propose deforming the metamaterial composed of cubic networks by stretching/compression along the main diagonal axis. We study the influence of the proposed deformation on the dispersion properties of the low-frequency mode: a spheroidal shape of isofrequency surfaces is predicted analytically and observed numerically, a longitudinal polarization of the mode is demonstrated.
10:30 - Non-reciprocal and topological infrared and optical metamaterials

Session chairperson(s): Ewold Verhagen; Alexander Khanikaev

10:30 - 11:00 - Non-Hermitian topology in synthetic optomechanical metamaterials Invited oral [Show abstract]
  • Ewold Verhagen, AMOLF, Netherlands
We create nano-optomechanical networks in which interactions between mechanical modes are induced and reconfigured through time-modulated optical forces. We study the nonreciprocal and topological states that emerge in such optomechanical metamaterials. We realize the bosonic Kitaev chain, which establishes a non-Hermitian topological phase with intriguing properties as amplifier and sensor.
11:00 - 11:15 - Non-Hermitian Linear Electrooptic Effect in 3D Materials Oral [Show abstract]
  • Tiago Morgado, Instituto de Telecomunicações and Department of Electrical Engineering, University of Coimbra, Portugal
  • Tatiana Rappoport, Physics Center of Minho and Porto Universities (CF-UM-UP), Portugal, and Instituto de Física, Universidade Federal do Rio de Janeiro, Brazil, Portugal
  • Stepan Tsirkin, Centro de Física de Materiales, Universidad del País Vasco, San Sebastián and Ikerbasque Foundation, Bilbao, Spain
  • Sylvain Lannebère, Instituto de Telecomunicações - Coimbra, Portugal
  • Ivo Souza, Centro de Física de Materiales, Universidad del País Vasco, San Sebastián and Ikerbasque Foundation, Bilbao, Spain
  • Mário Silveirinha, University of Lisbon–Instituto Superior Técnico and Instituto de Telecomunicações, Portugal
Here, we demonstrate that low-symmetry three-dimensional conductive materials with large Berry curvatures (e.g., doped trigonal tellurium) under a static electric bias may behave as “distributed transistors” and provide polarization-tunable nonreciprocal and non-Hermitian responses. It is shown that doped tellurium offers a non-Hermitian linear electrooptic response that may enable realizing electromagnetic isolators, as well as achieving circular dichroism, and importantly, optical gain.
11:15 - 11:30 - Symmetry-Based Classification of Chern Phases in Honeycomb Photonic Crystals Oral [Show abstract]
  • Rodrigo P. Câmara, Universidade de Lisboa and Instituto de Telecomunicações, Portugal
  • Tatiana G. Rappoport, Physics Center of Minho and Porto Universities and Universidade Federal do Rio de Janeiro, Portugal
  • Mário G. Silveirinha, Universidade de Lisboa and Instituto de Telecomunicações, Portugal
We develop a symmetry roadmap for identifying photonic Chern phases in honeycomb crystals, via tight-binding theory. It is shown that a topological gap can be opened up only when the nonreciprocal response exhibits even parity under reflections about the horizontal and vertical mirror axes of the hexagonal unit cell.
11:30 - 11:45 - Nonlocal Extension Of Axion Electrodynamics In Metamaterials Oral [Show abstract]
  • Eduardo Barredo-Alamilla, ITMO University, Russia
  • Maxim A. Gorlach, ITMO University, Russia
Recently, metamaterials have been suggested as a platform for probing axion physics. Here we present an extended version of axion electrodynamics including higher-ordered derivatives of the fields in the constitutive relations using nonreciprocal metamaterial structures. The proposed meta-atom design can realize exotic axion physics and opens avenues for applications in nonreciprocal photonics.
11:45 - 12:15 - Topological pseudo-spin gates, geometrical phases, and anomalous resonators based on them Invited oral [Show abstract]
  • Alexander Khanikaev, City College of New York, USA
Topological boundary modes, originating from the nontrivial topology of the bulk bands in electronic and classical-wave systems, exhibit fascinating properties. In topological photonics, the chiral or helical nature of boundary modes makes them robust, and endows them with additional internal structure – pseudo-spins. Here we introduce heterogeneous topological boundary modes, which are based on mixing two of the most widely used topological photonics platforms – the pseudo-spin-Hall-like (PSH) and valley-Hall (VH) photonic topological insulators. We demonstrate that PSH and VH phases are connected to one another by a unitary transformation, which allows us to implement full control over the respective pseudo-spins. We predict and confirm experimentally that the unitary transformation between different pseudo-spins, realized by geometrical transformations, enables a continuum of heterogeneous boundary states carrying both pseudo-spins and valley polarizations. When applied adiabatically to topological boundary modes, this transformation enables conversion between pseudo-spin and valley polarization, and vice versa. Thus, we demonstrate the possibility of flipping the pseudo-spin without back reflection and implement a unidirectional topological X-gate acting for synthetic spins. Finally, we show that such adiabatic evolutions give rise to a geometrical phase associated with the effective flux of the synthetic gauge field due to rotations on the combined spin-valley Bloch sphere. We directly observe the effect of this flux via interferometric Aharonov-Bohm type experiment on a silicon chip. Our results unveil a versatile approach to manipulating pseudo-spins of topological photonic states, and envision topological photonics as a powerful platform for integrated classical and quantum devices based on synthetic spins. To confirm this, we demonstrate an anomalous ring-resonator which is robust against shape and length deformation due to its purely geometrical nature, which does not require a dynamic phase for the resonance to occur.
12:15 - 12:30 - Equal Power Splitting in a Rotationally Symmetric Valley Photonic Junction Oral [Show abstract]
  • Christian Johnson-Richards, Newcastle University, United Kingdom
  • Alex Yakovlev, Newcastle University, United Kingdom
  • Victor Pacheco Peña, Newcastle University, United Kingdom
Topological valley photonic crystal based waveguides have shown to provide scattering resistance from lattice defects and sharp bends while maintaining a small footprint in photonics. In this work we present our latest efforts in designing a rotationally symmetric 6-port junction utilising topological valley mode waveguides that exhibits equal power spitting when excited at one port to ports 2, 4 and 6. To do this, a scattering matrix is carefully be extracted to analytically represent the structure, showing its potential in the design of topological structures for elementary computing processes.
10:30 - Modeling and control of scattering and radiation with metasurfaces

Session chairperson(s): Marco Di Renzo; Enrica Martini

10:30 - 11:00 - Design of Reconfigurable Intelligent Surfaces by Using S-Parameter Multiport Network Theory - Optimization and Full-Wave Validation No show [Show abstract]
  • Marco Di Renzo, CNRS & CentraleSupélec, Paris-Saclay University, France
Multiport network theory has been proved to be a suitable abstraction model for analyzing and optimizing reconfigurable intelligent surfaces (RISs), especially for studying the impact of the electromagnetic mutual coupling among radiating elements that are spaced less than half of the wavelength. Both representations in terms of Z-parameter (impedance) and S-parameter (scattering) matrices are widely utilized. In this talk, we embrace multiport network theory for analyzing and optimizing the reradiation properties of RIS-aided channels.
Media link(s):

Further information about the technical content of this presentation can be found in [1].

[1] Andrea Abrardo, Alberto Toccafondi, Marco Di Renzo: Design of Reconfigurable Intelligent Surfaces by Using S-Parameter Multiport Network Theory - Optimization and Full-Wave Validation. CoRR abs/2311.06648 (2023)

 

11:00 - 11:30 - Applicability of Physical Optics for Predicting the Diffraction Pattern of Binary Metasurfaces Invited oral [Show abstract]
  • Constantin Simovski, Aalto University, Finland
  • Sergei Tretyakov, Aalto University, Finland
  • Javad Shabanpour , Aalto University, Finland
In this paper, we outline the domain of adequacy for the well-known approximation of physical optics (PO) for binary metasurfaces (MSs). First, we show that beyond the approximation of so-called reflection locality (RL) PO cannot be applied for practical reflecting MSs. Next, in the framework of RL approximation we derive a closed-form expression for the diffraction pattern of a finite-size binary MS and compare the results with full-wave simulations. We show that PO may be applied for a binary MS if and only if the incident and deflection angles are sufficiently small, i.e. the MS period is sufficiently large. In this case, the desired anomalous reflection is due to one of the two first-order diffraction lobes, whose magnitudes are adequately predicted by PO. your abstract here
11:30 - 11:45 - Multilayer Purely Capacitive Metarefractor for Reflectionless Wide-Angle Anomalous Transmission Oral [Show abstract]
  • Federico Giusti, University of Siena, Italy
  • Matteo Albani, University of Siena, Italy
Metasurfaces (MTSs) are efficient tools for controlling electromagnetic radiation and manipulating local aperture fields. Metarefractors, electromagnetic devices capable of altering the direction of incident plane-waves, have gained significant attention in recent research. The known design approaches of metarefractors, namely impedance-equalized Huygens' MTS and omega-type bianisotropic MTS, rely on the hypothesis of local approximations, where the derived sheet admittance profiles are based on the uniform problem matching the local structure. The presence of poles and zeros in the closed-form solution of the admittance profiles, together with the non-uniqueness of the equivalent transmission line problem due to the infinite number of Floquet modes (FMs) resulting from periodic modulation, reduce the performance when implemented with physical elements. In this work, a multilayer approach based on FMs optimization is proposed for the design of a six-layer purely capacitive metarefractor performing a reflectionless 0$degree$-to-80$degree$ anomalous transmission. This approach overcomes the drawbacks associated with traditional methods, offering enhanced performance and versatility. Numerical results are validated using CST Studio Suite.
11:45 - 12:15 - Periodic Metasurface Design for Leaky Wave Radiation and Scattering Control Invited oral [Show abstract]
  • Enrica Martini, University of Siena, Italy
  • Stefano Maci, University of Siena, Italia
This contribution discusses recent advances in the field of electromagnetic field manipulation through periodic metasurfaces by using a unified description based on the Floquet Wave expansion of fields and currents and homogenized equivalent impedance models of the metasurfaces.
12:15 - 12:30 - Non-Decaying Leaky Surface Waves Oral [Show abstract]
  • Afshin Abbaszadeh, Virginia Tech, USA
  • Jordan Budhu, Virginia Tech, USA
A Sinusoidally Modulated Reactive Sheet (SMRS) can be designed to support TE or TM surface wave propagation with at least one spatial harmonic within the light cone. Due to radiative losses associated with the spatial harmonics within the light cone, the wavenumber of the fundamental surface wave is complex. In this work, we compensate the loss associated with the leakage by coupling the SMRS to an active impedance sheet. Solving the dispersion relation for the coupled configuration shows that at a particular modulation depth, the wavenumber associated with the dominant surface wave is purely real despite the radiative losses. Although an exceptional point has not been observed, the structure is reminiscent of the balanced gain and loss configuration of coupled waveguides exhibiting parity-time symmetry except here the loss is due to leaky wave radiation.
10:30 - Metamaterials for imaging and sensing III

Session chairperson(s): Andrea Di Falco; Constantinos Valagiannopoulos

10:30 - 11:00 - Holographic Metasurfaces for optical trapping, sensing and imaging in microfluidic environments Invited oral [Show abstract]
  • Tomasz Plaskocinski, University of St Andrews, United Kingdom
  • Jinaling Xiao, University of St Andrews, United Kingdom
  • Mohammad Biabanifard, University of St Andrews, United Kingdom
  • Andrea Di Falco, University of St Andrews, United Kingdom
We present our recent results on the translation of metasurface technology into microfluidic environments. We demonstrate that holographic metasurfaces can be used for optical trapping experiments, refractive index sensing and imaging applications.
11:00 - 11:15 - Optical Topological Picometrology At A Million Measurements Per Second: Seeing Beyond Brownian Motion Oral [Show abstract]
  • Cheng-Hung Chi, Optoelectronics Research Centre, University of Southampton, United Kingdom
  • Eric Plum, Optoelectronics Research Centre, University of Southampton, United Kingdom
  • Kevin MacDonald, Optoelectronics Research Centre, University of Southampton, United Kingdom
  • Nikolay Zheludev, Optoelectronics Research Centre, University of Southampton & Centre for Disruptive Photonic Technologies, TPI, SPMS, Nanyang Technological University, United Kingdom & Singapore
We demonstrate the position of a moving nano-object can be detected with sub-Brownian spatial and temporal resolution by analysing its coherent light scattering patterns using a deep learning algorithm. We experimentally achieve resolution better than 170 pm at sampling rates up to 1 million measurements per second.
11:15 - 11:30 - Picometrology With Topologically Structured Light: The Information Aspect Oral [Show abstract]
  • Thomas Grant, ORC, University of Southampton, United Kingdom
  • Anton Vetlugin, CDPT, Nanyang Technological University, Singapore
  • Eric Plum, ORC, University of Southampton, United Kingdom
  • Kevin MacDonald, ORC, University of Southampton, United Kingdom
  • Nikolay Zheludev, ORC, University of Southampton, United Kingdom
Optical localization metrology of nanoscale objects achieving sub-atomic precision using topologically structured light has recently been demonstrated. Here we report a Fisher Information analysis of this metrology, which provides understanding of how such performance, using phase singularities for resolution orders of magnitude beyond the conventional diffraction limit, is possible.
11:30 - 12:00 - Optimizing Layered Structures of Giant Polarization Selectivity Invited oral [Show abstract]
  • Constantinos Valagiannopoulos, National Technical University of Athens, Greece
Polarization of traveling waves, dictated by the direction of the time-varying electric field vector, makes a continuous information container being crucial in analog signal processing and, thus, state-of-the-art methods have been developed for the transformation or conversion of polarized beams. Three approaches leading to optimal layered strictures with colossal polarization sensitivity in absorption, scattering and nonreciprocal transmission are presented, based on variants of Particle Swarm Optimization (PSO), fully connected neural networks and tight sweeps along physically-inspired parametric paths. The obtained designs can be employed as ultra-efficient components in photonic integrated systems dealing with polarization-controlled applications such as sensing, optical isolation and angular momentum multiplexing.
12:00 - 12:15 - Versatile and High-NA Image Edge Detection Using Tamm Plasmon Polaritons Oral [Show abstract]
  • Bernardo Dias, University of Amsterdam, Netherlands
  • Jorik van de Groep, University of Amsterdam, Netherlands
By leveraging two Tamm Plasmon Polariton resonances at different wavelengths in a remarkably simple metal – photonic crystal – metal structure, we demonstrate image edge detection with both polarized and unpolarized light as well as a numerical aperture up to 0.9, one of the highest values reported yet.
12:15 - 12:30 - Diffractive order Mueller Matrix Spectroscopic Ellipsometry of polarization beam splitting metasurfaces Oral [Show abstract]
  • Morten Kildemo, NTNU, Norway
We present spectroscopic Mueller matrix ellipsometry in a diffractive order configuration, as a tool for the characterization of orthogonal polarization beam-splitters based on a-Si:H nanopillars. The spectroscopic Mueller matrix approach allows to study the physics of metasurface devices, and allows further for monitoring and control of the fabrication process, the initial design and produces feedback into the computational design.
10:30 - Metamaterials for nanophotonics and nanoantennas I

Session chairperson(s): Lei Shi; Philippe Tassin

10:30 - 11:00 - Inverse Design of Metamaterials and Photonic Crystals Using Machine Learning Invited oral [Show abstract]
  • Viktor Lilja, Chalmers University of Technology, Sweden
  • Albin. J. Svärdsby, Chalmers University of Technology, Sweden
  • Timo Gahlmann, Chalmers University of Technology, Sweden
  • Philippe Tassin, Chalmers University of Technology, Sweden
We present an overview of our work on inverse design of metamaterials and photonic crystals. In the past few years, we have developed neural networks that can provide new designs for nanophotonic structures with predefined optical response. In particular, we have developed a CGAN network that can provide lithographic masks for a meta-atom with desired transmission and reflection properties. We illustrate our machine-learning-based inverse design with examples of metasurfaces with refractive properties, metasurfaces with meta-atoms with interdependent properties, nonlinear photonic-crystal waveguides, and photonic-crystal membranes for optomechanical resonators.
11:00 - 11:15 - Inverse Design of Meta-Mirror Cavities for Polaritonic All-Optical Transistors Oral [Show abstract]
  • Jan David Fischbach, Institute of Nanotechnology at Karlsruhe Institute of Technology, Germany
  • Thomas Jebb Sturges, Institute of Theoretical Solid State Physics at Karlsruhe Institute of Technology, Germany
  • Pietro Tassan, IBM Research Europe - Zurich, ETH Zurich, Switzerland
  • Thilo Stöferle, IBM Research Europe - Zurich, Switzerland
  • Darius Urbonas, IBM Research Europe - Zurich, Switzerland
  • Rainer F. Mahrt, IBM Research Europe - Zurich, Switzerland
  • Fridtjof Betz, Zuse Institute Berlin, Germany
  • Felix Binkowski, Zuse Institute Berlin, Germany
  • Sven Burger, Zuse Institute Berlin, Germany
  • Carsten Rockstuhl, Institute of Nanotechnology and Institute of Theoretical Solid State Physics at Karlsruhe Institute of Technology, Germany
Ongoing efforts towards chip integrated all-optical polariton transistors use high contrast grating cavities for strong light-matter interaction. We present a compute-efficient and differentiable approach to model and design the resonant states of such cavities. The approach combines the T-matrix method with the AAA algorithm for complex pole finding.
11:15 - 11:30 - Inverse Design of Diffraction Fields with Metamask for Three-dimensional Oral [Show abstract]
  • Chihun Lee, Pohang University of Science and Technology (POSTECH), Korea (South)
  • Junsuk Rho, Pohang University of Science and Technology (POSTECH), Korea (South)
For proximity-field nanopatterning (PnP), a type of nanostructure fabrication with continuous transfer of interference, the geometry of the phase mask primarily determines the resolution of a fabricated nanostructure by modulating the phase shift of interference light. We introduce a novel approach using particle swarm optimization for concurrent optimization of phase masks, enhancing electric field intensity contrast. This enables the fabrication of uniform hexagonal nanochannel arrays with selective intensity control, overcoming previous design method.
11:30 - 11:45 - Nonlocal Metasurfaces with Giant Tunability Enabled by Kirigami Oral [Show abstract]
  • Freek van Gorp, University of Amsterdam, Netherlands
  • Jorik van de Groep, University of Amsterdam, Netherlands
  • Corentin Coulais, University of Amsterdam, Netherlands
Tunable metasurfaces enable active and on-demand control over optical wave fronts using reconfigurable scattering of resonant nanostructures. However, the tunability of the metasurface's resonant response is typically small. Here, we leverage novel insights from mechanical metamaterials to demonstrate optical metasurfaces with a giant tunability enabled by kirigami substrates. By introducing judiciously engineered cuts in a flexible substrate, we can stretch and compress the metasurface to unprecedented extent and thereby tune a high quality-factor resonance supported by a silicon nanoparticle array over a very large spectral range. Our results highlight a promising pathway towards flexible metasurfaces that offer unusually large tunability with applications in dynamic nanophotonic devices.
11:45 - 12:00 - Multi-functional Meta-surfaces Based on Coherent Wave Interference Oral [Show abstract]
  • Yuejiao Zhou, Fudan University, China
  • Tong Liu, The Hong Kong University of Science and Technology, Hong Kong
  • Changhong Dai, Fudan University, China
  • Dongyi Wang, Hong Kong Baptist University, Hong Kong
  • Lei Zhou, Fudan University, China
Multiple functionalities in compact devices is crucial in modern optics. We propose a novel method to design metadevices with versatile wave-control capabilities beyond conventional limits. Infinite number of polarization-tuned functionalities can be realized within one single meta-device when manipulating incident polarization, the idea of which is experimentally realized at 1550 nm.
12:00 - 12:30 - Manipulate light spatially and temporally by photonic crystal slabs in momentum space Invited oral [Show abstract]
  • Lei Shi, Fudan University, China
In this talk, I will present four of our recent experimental results. The first one is using photonic crystal slabs to generate optical vortices with phase singularities. The second one is realization of large polarization depended beam shift. The third one is to design photonic crystal slabs as a ultrathin reciprocal lens to realize upright real image. The last one is using photonic crystal slabs to realize spatial temporal vortices with transverse angular momentum.
12:30 - 14:00 - Lunch Break (Thursday)
14:00 - 15:30 - Oral Sessions (Thursday Afternoon 1)
14:00 - Synthetic motion in temporal metamaterials

Session chairperson(s): John Pendry; Filipa Prudencio

14:00 - 14:30 - Air conditioning for photons Invited oral [Show abstract]
  • John Pendry, Imperial College London, United Kingdom
A simple time dependent system is solved analytically taking the form of a moving step-up or step-down in refractive index. We demonstrate that step motion, by a process of compression or expansion, adds or subtracts energy from radiation passing through, so heating or cooling the photons
14:30 - 14:45 - Generalized Minkowskian Spacetime Crystals Oral [Show abstract]
  • Filipa Prudencio, Instituto de Telecomunicacoes - Instituto Superior Tecnico, Portugal
  • Mario Silveirinha, University of Lisbon – Instituto Superior Tecnico and Instituto de Telecomunicacoes, Portugal
Minkowskian spacetime crystals were recently introduced as time-variant systems described by constitutive relations that are observer independent. Here, we extend this concept to anisotropic biaxial crystals. We show that the electromagnetic response of such spacetime anisotropic crystals is indistinguishable from that of a moving photonic crystal.
14:45 - 15:15 - Synthetic Motion in Time-Varying Metamaterials Invited oral [Show abstract]
  • T. V. Raziman, Blackett Laboratory, Department of Physics, Imperial College London; Department of Mathematics, Imperial College London, United Kingdom
  • Stefano Vezzoli, Blackett Laboratory, Department of Physics, Imperial College London, United Kingdom
  • Anthony Harwood, Blackett Laboratory, Department of Physics, Imperial College London, United Kingdom
  • John B Pendry, Blackett Laboratory, Department of Physics, Imperial College London, United Kingdom
  • Simon A. R. Horsley, School of Physics and Astronomy, University of Exeter, United Kingdom
  • Richard V. Craster, Department of Mathematics, Imperial College London, United Kingdom
  • Riccardo Sapienza, Blackett Laboratory, Department of Physics, Imperial College London, United Kingdom
<p> We theoretically investigate light propagation through dispersive metamaterials with synthetic motion - i.e., travelling-wave modulations that mimic moving media. Our theory is general for any wave, and can also explain experimental results in the optical domain for time-modulated Indium Tin Oxide.</p>
15:15 - 15:30 - Mimicking the motion of metallic interfaces with spacetime switching Oral [Show abstract]
  • Diego Martinez Solis, University of Extremadura, Spain
  • Shixiong Yin, City University of New York, Photonics Initiative, Advanced Science Research Center, USA
  • Emanuele Galiffi, City University of New York, Photonics Initiative, Advanced Science Research Center, USA
  • Andrea Alu, City University of New York, Photonics Initiative, Advanced Science Research Center; City University of New York, Physics Program, Graduate Center, USA
  • Nader Engheta, University of Pennsylvania, Department of Electrical and Systems Engineering, USA
Inspired by the need of recognizing novel mechanisms to engineer time and spacetime inhomogeneities, we theoretically explore the possibilities of inducing fast temporal changes in the structural dispersion of a one-dimensional parallel-plate cavity. In this work, we delve into the variation of interplate distance not by actual motion of the cavity’s metallic boundaries, but through the effective subluminal synthetic motion that emerges from a judicious switching operation in the metallic region, parameterized as a lossless spacetime-varying plasma. We theoretically show how, depending on the nature of this time-dispersive switching process, different boundary conditions apply, providing richer physics than true motion.
14:00 - Tunable metasurfaces

Session chairperson(s): Lei Zhou; Alessio Monti

14:00 - 14:30 - Dielectric metasurfaces for controlling THz waves Invited oral [Show abstract]
  • Lei Zhou, Physics Department, Fudan University, China
I will present several recent examples of using carefully designed dielectric metasurfaces to control terahertz waves, either statically or dynamically.
14:30 - 14:45 - Terahertz Intelligent Metasurfaces by Vanadium Dioxide No show [Show abstract]
  • Biao-Bing Jin, Nanjing University, China
We presented our spatial light modulator and reconfigurable intelligent metasurfaces based on phase change material of vanadium dioxide. After successfully suppressing the cross talk from adjacent pixels, the terahertz wave could be modulated in a programable manner. By applying various coding sequences to the reconfigurable intelligent metasurfaces, it could deflect terahertz beams over an angle of 42 degree. We established a software-defined sensing reaction system for intelligent terahertz beams manipulation.
14:45 - 15:00 - Tunable Plasma-like Metamaterial with Rotating Elements Oral [Show abstract]
  • Rustam Balafendiev, University of Iceland, Iceland
  • Gagandeep Kaur, Stockholm University, Sweden
  • Gaganpreet Singh, Stockholm University, Sweden
  • Alex Millar, Fermi National Accelerator Laboratory, USA
  • Pavel Belov, ITMO University, Russia
  • Jon Gudmudsson, University of Iceland, Iceland
In this work we present a tunable plasma-like metamaterial consisting of pairs of rotating elements. Due to the changing interaction between the pairs in the process of tuning, the plasma frequency can be tuned by 28%. Simulations of an infinite medium are employed to investigate the dispersion of the proposed metamaterial. A microwave cavity is used to experimentally demonstrate the tuning from 9 to 12.1 GHz using the modes of the cavity.
15:00 - 15:30 - Microplasma arrays as reconfigurable refractive metasurfaces at microwave frequencies Invited oral [Show abstract]
  • Alessio Monti, Roma Tre University, Italy
  • Stefano Vellucci, Niccolò Cusano University & Metamorphose-VI, Italy
  • Mirko Barbuto, Niccolò Cusano University & Metamorphose-VI, Italy
  • Davide Ramaccia, Roma Tre University, Italy
  • Luca Stefanini, Roma Tre University, Italy
  • Alessandro Toscano, Roma Tre University, Italy
  • Filiberto Bilotti, Roma Tre University & Metamorphose-VI, Italy
In this contribution, we present the results of some preliminary investigations about the use of microplasma arrays as reconfigurable refractive metasurfaces at microwave frequencies. Through theoretical considerations and full-wave results, we demonstrate how reconfigurable Drude-like scatterers can serve as fundamental elements of multipolar metasurfaces, enabling full phase coverage in transmission. Additionally, we discuss the design of a reconfigurable planar lens capable of steering the beam emitted by an aperture antenna across a wide angular range.
14:00 - Advanced design of RF metasurfaces and metamaterials

Session chairperson(s): Giuseppe Vecchi; Jordan Budhu

14:00 - 14:15 - Analysis and Design of Inhomogeneous Lens Antennas through the Lax-Friedrichs Sweeping Method Oral [Show abstract]
  • Ilir Gashi, University of Siena, Italy
  • Stefano Maci, University of Siena, Italy
  • Matteo Albani, University of Siena, Italy
<p> In this paper, we explore a new method for analyzing Graded-Index (GRIN) lenses by applying the Lax-Friedrichs Sweeping Method. This numerical approach focuses on efficiently calculating both phase and amplitude in two-dimensional or three-dimensional spaces, offering a faster alternative to conventional ray tracing methods. We present the application of this numerical algorithm in the analysis of an inhomogeneous lens, aiming to demonstrate the effectiveness of our proposed method.</p>
14:15 - 14:30 - Inverse Design of 1D Photonics Oral [Show abstract]
  • Yakir Hadad, Tel-Aviv University, Israel
  • Ohad Silbiger, Tel-Aviv University, Israel
In this work, we apply gradient descent optimization constrained by Ricatti's equation to design one-dimensional photonic structures. We design several unorthodox filters using this approach, such as dual-band bandpass and various ultrawideband differentiators. The approach is shown to provide adequate solutions using trivial optimization starting points and, thus, is highly efficient.
14:30 - 15:00 - Inverse Design of Metal-Dielectric Metasurfaces for Antennas and RIS Invited oral [Show abstract]
  • Giuseppe Vecchi, Politecnico di Torino, Italy
  • Marcello Zucchi, Politecnico di Torino, Italy
  • Lucia Teodorani, Politecnico di Torino, Italy
  • Marco Righero, Links Foundation, Italy
  • Francesco Vernì, Huawei Italy, Italy
<p> The talk is about metasurfaces where metal elements are the main component, for antennas as well as RIS. The described method is based on the Integral Equation formulation, and does not require any solution of the forward problem during the iterations. Theoretical and practical realizability constraints are enforced in the algorithm.</p>
15:00 - 15:15 - A New Homogenization-Free Boundary Condition Towards Aperiodic Metasurface Design Using Full-Wave Surrogate Models of Printed Circuits Oral [Show abstract]
  • Jordan Budhu, Virginia Tech, USA
  • Raphael Pestourie, Georgia Tech, USA
A new homogenization-free boundary condition is introduced for the design of metasurfaces. The boundary condition, linking the tangential electric field to the induced surface current density within a unit cell, is described as a matrix equation containing a surrogate model of a printed circuit. Full-wave simulations are performed to construct the data needed to capture the physics of a printed circuit’s response to exciting fields in terms of its induced current density. The matrix equation takes the form of a boundary condition which can be included in design and optimization algorithms incorporating mutual coupling in the form of an impedance matrix. Modelling the metasurface in this manner allows for direct design of the realizable model avoiding any homogenization or locally periodic approximations leading to a paradigm shift in metasurface design approaches. The surrogate model’s construction is described and its use in a 50 printed circuit example is provided.
15:15 - 15:30 - Genetic Surfaces for Scattering Suppression Oral [Show abstract]
  • Mikhail Tsukerman, ITMO University,, Russia
  • Konstantin Grotov, Tel Aviv University, Israel
  • Anna Mikhailovskaya, Tel Aviv University, Israel
  • Pavel Ginzburg, Tel Aviv University, Israel
In the realm of advanced metamaterials, achieving broadband conformal electromagnetic cloaking remains an unsolved challenge. However, obtaining a weaker property of scattering suppression while complying with the practical constraints has value. Here, we introduce the concept of “genetic surfaces” - Evolutionary-designed flat and perspectively conformal electromagnetic structures capable of reducing the scattering cross-section of an arbitrary object at a broad frequency range. Specifically, we demonstrated a wideband ~30% fractional bandwidth ~20dB scattering suppression from several generic test objects: metal wire and wire-grid sphere. Genetic algorithms offer unparalleled advantages in complex, multi-objective optimization scenarios. Equipped with fast-forward solvers, these methods surpass traditional design techniques, paving the way for a new generation of devices.
14:00 - Metamaterials for imaging and sensing IV

Session chairperson(s): Ekaterina Shamonina; Oksana Shramkova

14:00 - 14:30 - Time-Domain Reflectometry for Imaging Conductive Environment Invited oral [Show abstract]
  • Georgiana Dima, University of Oxford, Department of Engineering Science, UK
  • Conor McMahon, University of Oxford, Department of Engineering Science, UK
  • Anna Radkovskaya, University of Oxford, Department of Engineering Science, UK
  • Eleanor O'Hara, School of Engineering, University of West of England, UK
  • Daffodil Dhayaa, University of Oxford, Department of Engineering Science, UK
  • Callum Long, University of Oxford, Department of Engineering Science, UK
  • Jiaruo Yan, FORTH-IESL, Greece
  • Laszlo Solymar, University of Oxford, Department of Engineering Science, UK
  • Ekaterina Shamonina, University of Oxford, Department of Engineering Science, UK
Time-domain reflectometry of magnetoinductive (MI) waves in metamaterials with inter-element coupling has been previously shown to enable contactless sensing of conductive objects. The basic principle is that conductive objects affect the resonant properties of elements of the array causing reflections of MI waves. In this work we demonstrate high-fidelity signal detection achieved by tuning the driving signal to the passband of MI waves. Feasibility of imaging of inhomogeneous conductive environment and achieving sub-unit-cell accuracy will be discussed, with potential applications ranging from quality control in 3D printing to medical imaging. Analytical, numerical and experimental results will be presented.
14:30 - 15:00 - High Sensitivity Vertical Waveguide-based Sensor for Polarization Independent Color Separation Invited oral [Show abstract]
  • Oksana Shramkova, imec, Belgium
  • Rossa Ciarnain, imec, Belgium
  • Farhan Ali, imec, Belgium
  • Bruno Figeys, imec, Belgium
  • Robert Gehlhaar, imec, Belgium
  • Jan Genoe, imec, Belgium
In this work we have developed a new type of polarization independent color splitter, which spectrally and spatially separates the light onto a Bayer-like sensor pattern below the multimode waveguides. The proposed topology helps to reduce the size of the color splitting element.
15:00 - 15:15 - 2D Localisation Using Magneto-Inductive Waveguides Oral [Show abstract]
  • Georgiana Dima, University of Oxford, United Kingdom
  • Ioannis Spanos, University of Oxford, United Kingdom
  • Christopher Stevens, University of Oxford, United Kingdom
This study investigated a two-dimensional(2D) magneto-inductive waveguide as a sensing device for low-conductivity samples, which mimic the effect of touchscreen interactions. A neural network was trained to predict the 2D location of a sample with conductivity of 0.64 S/m, using spectral components obtained from a single, asymmetrical probing point as features. The model achieved an accuracy of 99% up to 12 mm away from the surface. This research advances the potential implementation of magneto-inductive waveguides in touchscreen arrays and biomedical applications
15:15 - 15:30 - Substrate Choice for Sensors Based on THz Metasurfaces Oral [Show abstract]
  • Pradeep Tiwari, Institute of High Pressure Physics PAS, Poland
  • Deepak Kala, Institute of High Pressure Physics PAS, Poland
  • Maciej Sakowicz, Institute of High Pressure Physics PAS, Poland
We present an effect of substrate choice on terahertz metasurface sensors. The paper concentrates on terahertz metasurfaces and gives an overview of various substrates. Our simulations show that for all kinds of terahertz metasurfaces, it is beneficial for sensing to use low refractive index material as it increases sensitivity.
14:00 - Infrared and optical metastructures: experimental studies

Session chairperson(s): Georgia T. Papadakis; Tal Ellenbogen

14:00 - 14:30 - Phonon polaritons for mid-IR photonics Invited oral [Show abstract]
  • Georgia T. Papadakis, ICFO, Spain
  • Mitradeep Sarkar, ICFO, Spain
  • Gloria Davidova, ICFO, Spain
  • Michael Enders, ICFO, Spain
  • Maxime Giteau, ICFO, Spain
The phononic resonances of polar materials that occur at mid-infrared (IR) frequencies play a crucial role in radiative thermal management, since the blackbody spectrum at near-room temperatures peaks in the mid-IR spectral range. In this talk, I will show experimental results of antenna-like directional thermal emission using polar materials, that does not require any lithography. In addition, I will discuss the mid-IR response of transition-metal dichalcogenides that exhibit strong polar resonances and hyperbolicity. Finally, I will show experimental results on phase-change tunable thermal emission with In3SbTe3, an ideal material for active mid-IR nanophotonics.
14:30 - 15:00 - Composites as Enabling Optical Materials Invited oral [Show abstract]
  • Dorota A. Pawlak, ENSEMBLE3 Centre of Excellence and University of Warsaw, Poland
  • K. Bandopadhay, ENSEMBLE3 Centre of Excellence, Poland
  • N. Aghad, ENSEMBLE3 Centre of Excellence, Poland
  • P. Piotrowski, ENSEMBLE3 Centre of Excellence and University of Warsaw, Poland
  • M. Tomczyk, ENSEMBLE3 Centre of Excellence and University of Warsaw, Poland
  • K. Sadecka, ENSEMBLE3 Centre of Excellence, Poland
  • K. Markus, ENSEMBLE3 Centre of Excellence, Poland
  • A. Materna, ENSEMBLE3 Centre of Excellence, Poland
  • A. Bellardini, University of Rome “La Sapienza”, Italy
  • C. Sibilia, University of Rome “La Sapienza”, Italy
We report on developments in the composite materials based on crystalline and glass phases, and various dopants including quantum dots and plasmonic particles. We report on their properties and potential applications in the optoelectronics, photonics and energy applications.
15:00 - 15:15 - Cascading Disordered Resonant Metasurfaces: How to Assemble and Simulate Oral [Show abstract]
  • Miao Chen, LP2N, Institut d’Optique Graduate School, CNRS, Université de Bordeaux, France
  • Amit Sharma, Laboratory for Mechanics of Materials and Nanostructures, Empa, Swiss Federal Laboratories for Materials Science and Technology, Switzerland
  • Johann Michler, Laboratory for Mechanics of Materials and Nanostructures, Empa, Swiss Federal Laboratories for Materials Science and Technology, Switzerland
  • Xavier Maeder, Laboratory for Mechanics of Materials and Nanostructures, Empa, Swiss Federal Laboratories for Materials Science and Technology, Switzerland
  • Philippe Lalanne, LP2N, Institut d’Optique Graduate School, CNRS, Université de Bordeaux, France
  • Angelos Xomalis, Nanoelectronics and Photonics Group, Department of Electronic Systems, Norwegian University of Science and Technology, Norway
The visual appearance of nanoscale natural media always has been a paradigm in nanophotonics for achieving unique optical properties. Recently disordered manmade metasurfaces(MSs) allowed to harness specular and diffuse scattered light on-demand while preserving ultrathin and lightweight architectures. Thus, such unusual visual effects have been a step changer for innovative ultrathin coating technologies. We present here a method for fabrication and simulation of cascading disordered metasurface stacks. Off-plane electromagnetic coupling between MSs allows to manipulate separately specular reflection and diffuse light scattering from plasmonic nano-objects. We apply this unique functionality to realise large-scale diffuse light chromo-encryption. This work will guide material optimization for future innovative metasurface-based coating applications.
15:15 - 15:30 - Observation of Localized Resonant Phonon Polaritons in Biaxial α-MoO3 Nanoparticles Oral [Show abstract]
  • D. Beitner, Tel Aviv University, Israel
  • A. Farhi, Tel Aviv University, Israel
  • R.K. Nitharwal, Indian Institute of Technology, India
  • T. Dixit, Indian Institute of Information Technology Design and Manufacturing, India
  • T. Beitner, Tel Aviv University, Israel
  • S. Richtner, Tel Aviv University, Israel
  • S. Krishnan, Indian Institute of Technology,, India
  • H. Suchowski, Tel Aviv University, Israel
We synthesize biaxial nanoellipsoids using femtosecond-pulse laser ablation. We then derive an eigenmode theory for anisotropic particles and observe localized directional phonon polaritons of our synthesized particles using near-field spectroscopy, which agrees with our theory.
15:30 - 16:00 - Coffee Break (Thursday Afternoon)
16:00 - 18:15 - Oral Sessions (Thursday Afternoon 2)
16:00 - Time-modulated and exotic-property structures

Session chairperson(s): Andrea Alu; Ben Z. Steinberg

16:00 - 16:30 - Emergence of Quantum Electrodynamic Space-Time (QUEST) Metamaterials Invited oral [Show abstract]
  • Christophe Caloz, KU Leuven, Belgium
  • Amir Bahrami, KU Leuven, Belgium
  • Furkan Ok, KU Leuven, Belgium
  • Artuur Stevens, KU Leuven, Belgium
This paper discusses the emergence of QUantum Electrodynamic Space-Time (QUEST) systems and metamaterials, or QUESTs for short. These metamaterials are quantum extensions of Generalized Space-Time Engineered Modulation (GSTEM) systems, or GSTEMs, which we concisely presented in [1]. We briefly recall the fundamentals of GSTEMs and describe some key features of prospective photonic and electronic QUESTs.
16:30 - 17:00 - Symmetries and fundamental solutions in rotating metamaterials Invited oral [Show abstract]
  • Tomer Geva, Tel-Aviv University, Israel
  • Ido Kazma, Tel-Aviv University, Israel
  • Ben Z. Steinberg, Tel-Aviv University, Israel
<p> We explore the fundamental electrodynamic properties of rigidly rotating structures as observed in the structures’ rest frame of reference R^Omega. Symmetry properties associated with scattering from rotating individual meta-atoms dominated by quasi-static dynamics as well as full-range wave-dynamics in complex structures consisting such elements, are exposed. The interplay of rotation-induced gain and loss in dihedral symmetry groups is discussed, and the potential use such symmetries for rotation-sensitivity enhancement is explored. These effects potentially pave the way to a new class of devices and applications</p>
17:00 - 17:30 - Perfect All-Angular Nonlocal Metasurfaces via the Generalized Huygens' Condition Invited oral [Show abstract]
  • Amit Shaham, Technion-Israel Institute of Technology, Israel
  • Ariel Epstein, Technion-Israel Institute of Technology, Israel
We highlight the importance of the recently derived generalized Huygens' condition in realizing physically-meaningful nonlocal metasurfaces (MSs) with optimal performance across the entire (visible) spatial spectrum. The pivotal role of the corresponding (normal-susceptbility-enabled) grazing angle Huygens' condition is demonstrated by the synthesis of a symmetric omnidirectionally reflectionless MS for radome applications and an asymmetric spatial differentiator for analog computing, verified via full-wave solvers. For the symmetric case, direct closed-form translation of the required surface susceptibility tensor into an impedance sheet cascade is formulated, facilitating experimental validation. These results pave the path towards a systematic framework for devising versatile, realistic and efficient, nonlocal MSs.
17:30 - 18:00 - Complex Wave Phenomena in Hyperbolic Metasurfaces Invited oral [Show abstract]
  • Andrea Alu, City University of New York, USA
Hyperbolic metasurfaces have been offering an interesting platform to tailor waves, enabling subdiffractional wave propagation thanks to their anisotropic features and open-topology dispersion. In this work, I discuss the application of the peculiar propagation features of hyperbolic surface waves in complex geometries. I discuss in particular the emergence of hyperbolic wave attractors in oddly shaped cavities formed by extremely anisotropic media, and the design and implementation of hyperbolic lenses that mimic the problem of optimal airplane boarding in an analog-domain computing platform driven by hyperbolic surface waves.
16:00 - Heat flow and radiation

Session chairperson(s): Sander Mann; Inigo Liberal

16:00 - 16:30 - Kirchhoff’s laws of thermal radiation for complex, nonreciprocal, and time-varying materials Invited oral [Show abstract]
  • Sander Mann, Advanced Science Research Center, USA
  • Dimitrios Sounas, Wayne State University, USA
  • Andrea Alù, Advanced Science Research Center, USA
Absorption and emission of thermal radiation can be manipulated in novel and unintuitive ways in advanced metamaterial environments. We present fundamental relationships between the emission and absorption in complex, nonreciprocal, and time-varying materials, and discuss resulting fundamental bounds.
16:30 - 17:00 - Molecular Polaritons as Quantum Impurity Models Invited oral [Show abstract]
  • Joel Yuen-Zhou, University of California San Diego, USA
In the collective strong coupling regime where N molecules couple to an optical cavity mode, molecular polaritons may be regarded as quantum impurity models, where the impurity is a photon and the complex anharmonic molecular degrees of freedom serve as a bath. If this bath is large enough (N>>1), as in the case of most molecular polariton experiments, the quantum dynamics of such a system becomes very simple to compute and simulate [1,2], as demonstrated in our recent method, Collective Dynamics using Truncated Equations (CUT-E) [3,4]. The conceptual implications of this method are also discussed in light of recent experiments in polariton chemistry, where there is increasing evidence that strong coupling affects molecular properties and processes. Intriguing consequences of finite N effects are discussed in light of quantum sensing and spectroscopy.
17:00 - 17:30 - Thermal Emission From Singular And Time-modulated Systems Invited oral [Show abstract]
  • Inigo Liberal, Universidad Publica de Navarra, Spain
Thermal emission is a ubiquitous and fundamental radiative process that also underpins major technological applications for energy harvesting, heat management, and imaging. In our talk, we will review the latest advances in the field of controlling thermal emission with metamaterials, including time-varying media, coherent perfect absorption and non-Hermitian phase transitions.
17:30 - 18:00 - Radiative cooling for thermal management of optoelectronic devices Invited oral [Show abstract]
  • Qiaoqiang Gan, KAUST, Saudi Arabia
We will discuss the potential of passive cooling technology to reduce the operational temperature of selected optoelectronic devices and highlight potential pitfalls to avoid in radiative cooling reporting.
16:00 - Engineered metastructures for microwave and mm-wave applications

Session chairperson(s): Giacomo Oliveri; Alessio Monti

16:00 - 16:15 - High-Q Factor Dual-Layer Anapole Metamaterial Oral [Show abstract]
  • Maria Cojocari, University of Eastern Finland, Finland
  • Grigorii Matveev, University of Eastern Finland, Finland
  • Ladislau Matekovits, Politecnico di Torino, Italy
  • Polina Kuzhir, University of Eastern Finland, Finland
  • Alexey Basharin, University of Eastern Finland, Finland
We present simulation results and experimental study of a free standing dual-layer metamaterial with a high Q-factor in the mm-wave frequency range. High Q-factor resonance is achieved through combining resonances from two complementary planar metamaterials. This unique metamaterial displays potential for antennas, qubits, and phase shifters due to its properties arising from interactions between different multipole moments.
16:15 - 16:30 - Cloaking and Transparent Metasurfaces with Anapole and Pseudo-Anapole States Oral [Show abstract]
  • V. P. Sarin, Department of Electronics, Govt. College Tanur, Malappuram, Kerala, India
  • Giuseppe Labate, TNO - Radar department, Netherlands
  • Rohith K. Raj, Department of Electronics, Govt. College Mananthavady, Wayanad, Kerala, India
  • Vasudevan Kesavath, CREMA Lab, Department of Electronics, Cochin University of Science and Technology, Kerala, India
Split Ring Resonators (SRRs) are a promising architecture in order to design cloaking and transparent metasurfaces. According to the multipole decomposition, electric, magnetic and toroidal dipoles are induced on each SRR forming the so called anapole state for cloaking purpose and pseudo-anapole state for transparency. Results for both cases are experimentally validated using microwave measurements in an anechoic chamber facility.
16:30 - 17:00 - Hyperuniform Disordered Meta-Structures Invited oral [Show abstract]
  • Orestis Christogeorgos, Queen Mary University of London, United Kingdom
  • Yang Hao, Queen Mary University of London, United Kingdom
There exists an exotic type of matter that has been found in many natural and biological systems, which is termed as hyperuniform disordered. Here, we illustrate how this naturally optimized and robust distribution, when employed in the metasurface or antenna array design can lead to broadband performance enhancement.
17:00 - 17:15 - Incidence Independent Metamaterial Absorber for Biomedical Sensing Application Oral [Show abstract]
  • Nipun Kumar Mishra, Guru Ghasidas Vishwavidyalaya Bilaspur, India
  • Laxmikant Dewangan, Guru Ghasidas Vishwavidyalaya Bilaspur, India
This paper investigates and presents a high Q-factor, polarization, and incidence angle-independent metamaterial (MM) absorber for biomedical sensing applications. The sensitivity of the proposed structure to refractive index and permittivity are analyzed. The structure consists of a simple 90-degree rotated S-shape geometry imprinted on an easily available FR-4 (lossy) dielectric substrate. The structure is operating at a microwave frequency range i.e., 4.3 GHz, having 99% absorptivity. The absorption mechanism of the structure is described with the help of top and bottom surface current distribution, and induced electric field. A high Q-factor structure shows an excellent polarization angle insensitivity to both TE and TM polarized waves. The structure is also investigated under oblique incidence electromagnetic (EM) wave and the 99% absorptivity holds up to 60° for both TE and TM polarized EM waves. Corresponding to the operating frequency the periodicity of the unit cell is 0.21λ0. The shift in absorption frequency depends on alteration in the permittivity and refractive index of the analyte placed on the MM absorber which can be utilized to sense the bio cells to identify the abnormality or infection. The advantages of small thickness, high Q-factor, polarization, angular insensitiveness, and frequency flexibility, make the proposed metamaterial absorber to several biomedical applications.
17:15 - 17:30 - Low cost 3D printable metamaterial for focused orbital angular momentum generation using mm-wave radar chip technology Oral [Show abstract]
  • Michael Töfferl, Graz University of Technology, Austria
  • Alexander Schossmann, Graz University of Technology, Austria
  • Alexander Bergmann, Graz University of Technology, Austria
  • Peter Banzer, University of Graz, Austria
We present a metamaterial for orbital angular momentum generation in the millimeter wave regime that can be fabricated with low-cost fused deposition modeling (FDM) 3D printers. The metamaterial induces a spatially distributed phase shift on millimeter waves, passing through the sample, via a spatial variation of the effective permittivity. We use an analytical model to calculate the effective permittivity of the metamaterial unit cell, which consists of a square block made of a dielectric with a cylindrical air hole at its center. The analytical model is used to design a metasurface that generates a beam carrying orbital angular momentum of order 1. We prove this concept in a laboratory setup using a commercially available millimeter wave chip as the source.
17:30 - 18:00 - Towards the METAVERSE: Revolutionizing Wireless Networks with the Smart Electromagnetic Environment Invited oral [Show abstract]
  • Arianna Benoni, ELEDIA@UniTN, DICAM, University of Trento, Italy
  • Giacomo Oliveri, ELEDIA@UniTN, DICAM, University of Trento, Italy
  • Lorenzo Poli, ELEDIA@UniTN, DICAM, University of Trento, Italy
  • Paolo Rocca, ELEDIA@UniTN, DICAM, University of Trento, Italy
  • Marco Salucci, ELEDIA@UniTN, DICAM, University of Trento, Italy
  • Francesco Zardi, ELEDIA@UniTN, DICAM, University of Trento, Italy
  • Andrea Massa, ELEDIA@UniTN, DICAM, University of Trento, Italy
The objective of this invited talk will be to review recent advances in Snart Electromagnetic Environment concepts and their application in the METAVERSE scenario, discussing the advantages/limitations of the most popular design and control strategies and highlighting the current research trends and envisaged challenges in this field.
16:00 - Metastructures for wave routing and processing

Session chairperson(s): Misha Sumetsky; Matthieu Malléjac

16:00 - 16:30 - M3: A Multidisciplinary Framework for Metamaterial Engineering Education Invited oral [Show abstract]
  • Mattia Biesuz, University of Trento, Italy
  • Marco Broccardo, University of Trento, Italy
  • Oreste Bursi, University of Trento, Italy
  • Francesco Dal Corso, University of Trento, Italy
  • Vigilio Fontanari, University of Trento, Italy
  • Andrea Massa, ELEDIA@UniTN - DICAM, University of Trento, Italy
  • Giacomo Oliveri, ELEDIA@UniTN - DICAM, University of Trento, Italy
  • Alessandro Pegoretti, University of Trento, Italy
  • Paolo Rocca, ELEDIA@UniTN - DICAM, University of Trento, Italy
  • Emiliano Rustighi, University of Trento, Italy
With the advancement and development of several research and industrial applications of Metamaterials (MTM), the topic of MTM education is gathering an increasing interest across various disciplines. Unlike more traditional topics, MTM education inherently requires a multi-disciplinary approach that encompasses fundamental and advanced topics in electromagnetic, mechanical, acoustic, electronic, material, and structural engineering. A new pedagogical approach towards MTM teaching is illustrated in this invited talk which is aimed at the education of trans-disciplinary experts in the field.
16:30 - 17:00 - Transformation and Amplification of Light in Photonic Waveguides and Resonators Modulated by a Relatively Slow Travelling Wave Invited oral [Show abstract]
  • Misha Sumetsky, Aston University, United Kingdom
<p> The behavior of electromagnetic waves in a medium modulated in time and space, largely investigated decades ago, has recently attracted emerging interest. Here, we address one of the thrilling questions of this research: can light with initial frequency w0 be amplified in a realistic photonic circuit modulated by a travelling wave having a frequency wp much smaller than w0? A positive answer to this question for an ideal lossless and dispersionless waveguide was given several decades ago. Generally, the bandwidth of the generated optical frequency comb spectrum can be dramatically enhanced when the traveling wave phase velocity vp approaches the phase velocity of light v0. However, for realistic optical waveguides, the amplification effect remains small. In contrast, we show that modulating a racetrack optical resonator by a traveling wave with a phase velocity vp much smaller v0 (rather than with a synchronous vp~v0) can significantly amplify light within a relatively small bandwidth.</p>
17:00 - 17:15 - Backpropagation-free Training of Analog AI Accelerators Oral [Show abstract]
  • Ali Momeni, Laboratory of Wave Engineering, Department of Electrical Engineering, EPFL, CH-1015 Lausanne, Switzerland, Switzerland
  • Babak Rahmani, Microsoft Research, 198 Cambridge Science Park, CB4 0AB Cambridge, UK, UK
  • Matthieu Mall´ejac, Laboratory of Wave Engineering, Department of Electrical Engineering, EPFL, CH-1015 Lausanne, Switzerland, Switzerland
  • Philipp del Hougne, Univ Rennes, CNRS, IETR - UMR 6164, F-35000, Rennes, France, France
  • Romain Fleury, Laboratory of Wave Engineering, Department of Electrical Engineering, EPFL, CH-1015 Lausanne, Switzerland, Switzerland
Deep learning has achieved remarkable success in diverse fields in recent years. However, this growth presents significant challenges, particularly in terms of energy consumption during both training and inference phases. While there have been efforts to improve energy efficiency during the inference phase, efficient training of deep learning models remains a largely unaddressed challenge. The training method for digital deep learning models typically relies on backpropagation, a process that is difficult to implement physically due to its reliance on precise knowledge of forward-pass computations in neural networks. To overcome this issue, We present a physics-compatible deep neural network architecture, augmented by a biologically-inspired learning algorithm referred to as physical local learning (PhyLL). This framework allows for the direct training of deep physical neural networks, comprising layers of physical nonlinear systems. Notably, our approach dispenses with the need for detailed knowledge of the specific properties of these nonlinear physical layers. Our approach outperforms state-of-the-art hardware-aware training methods by enhancing training speed, reducing digital computations and power consumption in physical systems, particularly in optics.
17:15 - 17:30 - Hybrid Nonlinear Graphene–Gold Metasurfaces Oral [Show abstract]
  • Anna Theodosi, University of Crete; Foundation for Research and Technology Hellas, Greece
  • Odysseas Tsilipakos, National Hellenic Research Foundation, Greece
  • Anastasios Koulouklidis, Foundation for Research and Technology Hellas, Greece
  • Isaac Appiah Otoo, University of Eastern Finland, Finland
  • Polina Kuzhir, University of Eastern Finland, Finland
  • Stelios Tzortzakis, University of Crete; Foundation for Research and Technology Hellas, Greece
  • Maria Kafesaki, University of Crete; Foundation for Research and Technology Hellas, Greece
Graphene is an attractive two dimensional material for nonlinear applications in the THz regime, due to its high third order nonlinearity and the ability to support tightly confined surface plasmons. In this work, we target a hybrid gold-patch/uniform-graphene metasurface implementation that is friendlier to an experimental demonstration compared to patterned graphene approaches and, at the same time, aims to further increase the efficiency of the third harmonic generation process. The efficiency of the nonlinear process is enhanced by spectrally aligning the fundamental and third harmonic frequencies with resonances of the metasurface, leading to spatiotemporal energy confinement in both steps, of excitation at ω and radiation at 3ω. Efficiencies as high as -15dB (3.2%) for input intensity 0.1 MW/cm2 are theoretically demonstrated. The nonlinear metasurface is fabricated and strong frequency shifts due to self-phase modulation are experimentally observed. These nonlinear shifts are verified by corresponding simulations. Our results highlight the potential of graphene-based metasurfaces for nonlinear applications.
17:30 - 17:45 - Multiscale AGILE (Axially Graded Index LEns) – Immersion Graded Index to Channel Light Oral [Show abstract]
  • Olav Solgaard, Stanford University, USA
  • Oliver Trojak, University of Southampton, UK
  • Nina Vaidya, University of Southampton, UK
The operational principle of the AGILE is based on the fact that the number of states of an optical aperture is proportional to the square of the refractive index (n), which allows concentration by a factor of n^2. The constant brightness theorem (invariance of luminance), although fundamental, is not complete as it is traditionally stated. Higher brightness, i.e., luminance (optical power flow per unit of area and solid angle) can be achieved inside a high-index material. An AGILE using immersion graded index is able to accept all input modes and concentrate light without tracking the source. Experimental results of up to 10x AGILE optical concentrator will be presented that also explore the relationship between acceptance angles and concentration ratios. The material layers, creating a wide range of graded-refractive indices, let in a broad spectrum of light, from near ultraviolet to infrared, while concentrating the light at the output. Furthermore, multiscale multifunctionality of the concept is demonstrated by AGILE device that is scaled-down and used in reverse; to increase light extraction many fold from emitters in high-refractive-index solid-state systems at the quantum level. Realized due to new fabrication techniques and materials design, these demonstrations of extreme graded-index immersion optics, not seen in nature or the present optics industry, will be presented. These prototypes are suitable for a tile-able array approach or structured metasurfaces for various applications; such as, solar concentration, laser coupling and waveguides, displays, solid-state lighting, and quantum computing.
17:45 - 18:15 - Polarization Transformation, Distribution, Multiplexing, and Entanglement Based on Optical Metasurfaces Invited oral [Show abstract]
  • Mu Wang, Nanjing University, China
  • Ruwen Peng, Nanjing University, China
Manipulating the polarization state of light is essential for classical and quantum information techniques. Traditional optical elements like waveplates and polarization beam splitters are usually bulky and heavy and do not meet the requirements for miniaturizing and integrating information systems. Metasurfaces offer a solution to these challenges. Here, we present our studies on polarization transformation, distribution, entanglement, and multiplexing with optical metasurfaces, which significantly miniaturize optical systems. By introducing geometrical-scaling-induced (GSI) phase modulations, we are able to generate different types of polarization states simultaneously from a single metasurface. Further, we demonstrate that the entangled photon pairs may interact with metasurface building blocks with the GSI phase and transform into two-photon entangled states with the desired polarization. Two metasurfaces, each simultaneously distributing polarization-entangled photons to spatially separated multiple channels M (N), accomplish M × N channels of entanglement distribution and transformation. We also show a strategy to break the fundamental limit of polarization multiplexing capacity of metasurfaces by introducing the engineered noise to the precise solution of Jones matrix elements. The conventional restriction of polarization multiplexing roots from the dimension constraint of the Jones matrix. This approach suggests a new paradigm for high-capacity optical displays, information encryption, and data storage.
16:00 - Metamaterials for nanophotonics and nanoantennas II

Session chairperson(s): Mario Silveirinha; Nahid Talebi

16:00 - 16:30 - Chiral-Gain Photonics Invited oral [Show abstract]
  • Mario Silveirinha, University of Lisbon - Instituto Telecomunicacoes, Portugal
I will present our most recent theoretical explorations of non-equilibrium optical systems with chiral-gain. I will analyze the impact of chiral-gain in both classical and quantum platforms and highlight the topological origin of some of these systems.
16:30 - 16:45 - Multichannel Photon Emission Based on Quantum Emitter Coupled Holography Metasurfaces Oral [Show abstract]
  • Yinhui Kan, University of Southern Denmark, Denmark
  • Xujing Liu, University of Southern Denmark, Denmark
  • Shailesh Kumar, University of Southern Denmark, Denmark
  • Sergey Bozhevolnyi, University of Southern Denmark, Denmark
We develop the multichannel holography approach for flexibly designing on-chip quantum emitters -coupled metasurfaces that can efficiently outcouple QEs-excited surface plasmon polaritons to photon emission propagating in designed multiple directions and carrying specific spin and orbital angular momenta.
16:45 - 17:00 - High-efficiency coupling of on-chip photonic system with metasurfaces Oral [Show abstract]
  • Shulin Sun, Fudan University, China
Here, we introduce a new scheme to design meta-couplers for achieving the controllable coupling of on-chip waveguide systems via controlling the spin states of illumination lights. Besides, we finally demonstrate background-free excitation of a nanocavity with local field enhanced by over 1000 times, based on a specifically designed meta-coupler.
17:00 - 17:15 - Broad and Tunable Properties of Plasmonic Multilayer Metamaterials merging Nitrides, Oxynitrides, and Transparent Conductors Oral [Show abstract]
  • Cristina Mancarella, Politecnico di Milano, Italy
  • Claudia Hallqvist, Politecnico di Milano, Italy
  • Simone Bossetti, Politecnico di Milano, Italy
  • Ludovica Tovaglieri, Politecnico di Milano, Italy
  • Gianluigi Baiardi, Politecnico di Milano, Italy
  • Alessio Lamperti, CNR-IMM, Italy
  • Vincenzo Caligiuri, Università della Calabria, CNR-Nanotec, Italy
  • Antonio De Luca, Università della Calabria, CNR-Nanotec, Italy
  • Andrea Li Bassi, Politecnico di Milano, CNST-IIT, Italy
The established potentialities of plasmonics in boosting light-matter interactions are fundamental for next-generation metamaterials merging multifunctionality, tunability and broader spectral responses. The archetypal metals show limited modulation outside VIS. Here, original hyperbolic metamaterials exploiting alternatives (transparent conductors, nitrides-oxynitrides) were developed to pursue tailorable characteristics in VIS-IR towards extreme light manipulation.
17:15 - 17:30 - Multi-layer Meta-Devices Enabling Advanced Applications: 6G and Beyond Oral [Show abstract]
  • Jingcheng Zhang, City University of Hong Kong, Hong Kong
In this work, we have developed advanced meta-devices tailored for sixth-generation (6G) communication systems.
17:30 - 18:00 - Ultrafast Cathodoluminescence Spectroscopy with Electron-Driven Photon Sources Invited oral [Show abstract]
  • Nahid Talebi, Kiel University, Germany
Probing the dephasing time of material excitations in solid-state systems is crucial for the next generation of quantum-related solid-state technologies. Here, we demonstrate how cathodoluminescence spectroscopy merged by electron-driven photon sources can be used to probe the dephasing time of exciton polaritons and single-photon emitters at sub-femtosecond time and nanometer spatial resolutions.
18:15 - 18:45 - Closing Ceremony

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