A5028737213- Metamaterials and Metasurfaces Applications
- Advanced Antenna and Metasurface Technologies
- Antenna Design and Analysis
- Photonic Crystals and Applications
- Plasmonic and Surface Plasmon Research
- Photonic and Optical Devices
- Thermal Radiation and Cooling Technologies
- solar cell performance optimization
- Terahertz technology and applications
- Advanced Wireless Communication Technologies
- Optical Coatings and Gratings
- Solar Thermal and Photovoltaic Systems
- Topological Materials and Phenomena
- Perovskite Materials and Applications
- Orbital Angular Momentum in Optics
- Energy Harvesting in Wireless Networks
- Superconducting and THz Device Technology
- Liquid Crystal Research Advancements
- Electromagnetic Scattering and Analysis
- Graphene research and applications
- Advanced Numerical Analysis Techniques
- Microwave Engineering and Waveguides
- Advanced Materials and Mechanics
- Modular Robots and Swarm Intelligence
- Millimeter-Wave Propagation and Modeling
National and Kapodistrian University of Athens
2023-2025
Foundation for Research and Technology Hellas
2014-2024
University of Crete
2023
FORTH Institute of Electronic Structure and Laser
2014-2021
FORTH Institute of Computer Science
2019
Aristotle University of Thessaloniki
2009-2012
Institute for Microelectronics and Microsystems
2009
Abstract Metasurfaces, the ultrathin, 2D version of metamaterials, have recently attracted a surge attention for their capability to manipulate electromagnetic waves. Recent advances in reconfigurable and programmable metasurfaces greatly extended scope reach into practical applications. Such functional sheet materials can enormous impact on imaging, communication, sensing applications, serving as artificial skins that shape fields. Motivated by these opportunities, this progress report...
We present an experimental demonstration and interpretation of ultrafast optically tunable, graphene-based thin film absorption modulator for operation in the THz regime. The component consists a uniform CVD-grown graphene sheet stacked on SU-8 dielectric substrate that is grounded by metallic ground plate. structure shows enhanced originating from constructive interference impinging reflected waves at absorbing sheet. modulation this absorption, which demonstrated via time-domain...
Here we present a roadmap on Photonic metasurfaces. This document consists of number perspective articles different applications, challenge areas or technologies underlying photonic Each will introduce the topic, state art as well give an insight into future direction subfield.
How might one make metasurfaces ``intelligent'', to offer multiple reconfigurable functions? The authors show that it can be done by embedding individually addressable tunable chips (mixed-signal integrated circuits) in each unit cell. This enables independent, continuous control of both the resistive and reactive parts local complex surface impedance. allows a broader range functionalities, among which arbitrary-angle perfect absorption anomalous reflection are showcased this study. Further...
In this paper we present the theoretical considerations and design evolution of a proof-of-concept reconfigurable metasurface, primarily used as tunable microwave absorber, but also wavefront manipulation polarization conversion device in reflection. We outline all taken into account, from selection patch shape, unit cell size, substrate, to topology structure that realizes desired tunability. The presented conforms fabrication restrictions is co-designed work with an integrated circuit chip...
Metasurfaces, ultrathin and planar electromagnetic devices with sub-wavelength unit cells, have recently attracted enormous attention for their powerful control over waves, from microwave to visible range. With tunability added the programmable metasurfaces enable us benefit multiple unique functionalities controlled by external stimuli. In this review paper, we will discuss recent progress in field of elaborate on different approaches realize them, global aspects, local software-defined...
Abstract A novel approach for reconfigurable wavefront manipulation with gradient metasurfaces based on permittivity‐modulated elliptic dielectric rods is proposed. It shown that the required 2π phase span in local electromagnetic response of metasurface can be achieved by pairing lowest magnetic dipole Mie resonance a toroidal resonance, instead using two resonances corresponding to fundamental electric and as customarily exercised. This allows precise matching both frequencies quality...
Programmable metasurfaces have garnered significant attention as they confer unprecedented control over the electromagnetic (EM) response of any surface. Such feature has given rise to novel design paradigms such Software-Defined Metamaterials (SDM) and Reconfigurable Intelligent Surfaces (RIS) with multiple groundbreaking applications. However, development programmable tailored particularities a potentially large application pool becomes daunting task because space remarkably large. This...
We present a thorough investigation of the electromagnetic resonant modes supported by systems polaritonic rods placed at vertices canonical polygons. The study is conducted with rigorous finite-element eigenvalue simulations. To provide physical insight, simulations are complemented coupled mode theory (the analog LCAO in molecular and solid state physics) lumped wire model capturing coupling-caused reorganizations currents each rod. rods, which form all-dielectric cyclic metamolecules,...
Software-defined metasurfaces are electromagnetically ultra-thin, artificial components that can provide engineered and externally controllable functionalities. The control over these functionalities is enabled by the metasurface tunability, which implemented embedded electronic circuits modify locally surface resistance reactance. Integrating controllers within able them to intercommunicate adaptively reconfigure, thus imparting a desired electromagnetic operation, opens path towards...
The radiative cooling of objects during daytime under direct sunlight has recently been shown to be significantly enhanced by utilizing nanophotonic coatings. Multilayer thin film stacks, 2D photonic crystals, etc. as coating structures improved the thermal emission rate a device in infrared atmospheric transparency window reducing considerably devices' temperature. Due increased heating photovoltaic (PV) devices - that significant adverse consequences on both their efficiency and life-time...
Abstract Outdoor devices comprising materials with mid-IR emissions at the atmospheric window (8–13 μm) achieve passive heat dissipation to outer space (~ − 270 °C), besides atmosphere, being suitable for cooling applications. Recent studies have shown that micro-scale photonic patterning of such further enhances their spectral emissivity. This approach is crucial, especially daytime operation, where solar radiation often increases device load. However, sub-optimal other wavelengths 8–13 μm,...
Solar cell technology requires materials that are efficient, lightweight, and stable. Organic–inorganic lead halide perovskite- polymer-based bulk heterojunction solar cells have emerged as highly promising, ultralightweight, flexible, efficient power sources. However, they suffer from limited stability, which is significantly affected by the temperature, in addition to other factors like oxidization moisture absence of appropriate encapsulation. Here, performing a coupled...
The next generation of wireless networks is expected to tap into the terahertz (0.1--10 THz) band satisfy extreme latency and bandwidth density requirements future applications. However, development systems in this challenging as THz waves confront severe spreading penetration losses, well molecular absorption, which leads strong line-of-sight through highly directive antennas. Recently, reconfigurable intelligent surfaces (RISs) have been proposed address issues derived from...
Abstract Optical activity (polarization rotation of light) is one the most desired features chiral media, as it important for many polarization‐related applications. However, in THz region, media with strong optical are not available nature. Here, a metamaterial (CMM) structure composed pairs vertical U‐shape resonators “twisted” arms studied, and revealed that demonstrates large pure (i.e., associated negligible transmitted wave ellipticity) low regime. The experimental data show...
Metasurfaces (MSs) have been utilized to manipulate different properties of electromagnetic waves. By combining local control over the wave amplitude, phase, and polarization into a single tunable structure, multi-functional reconfigurable metasurface can be realized, capable full incident radiation. Here, we experimentally validate architecture for microwave regime, where in principle variable loads are connected behind backplane reconfigurably shape complex surface impedance. As...
A deep understanding of how solution-processed solar cells (SSCs) perform under varying temperatures and irradiance is crucial for their optimal design, synthesis, use. However, current partial spectral characterization, primarily below the band gap wavelengths (λ < λg), limits insights into full operation. In this work, we expand knowledge by providing comprehensive full-spectrum experimental optical characterizations (∼300-2500 nm) theoretical optical-thermal-electrical analysis most...
Tunable metasurfaces are ultra-thin, artificial electromagnetic components that provide engineered and externally adjustable functionalities. The programmable metasurface, the HyperSurFace, concept consists in integrating controllers within metasurface interact locally communicate globally to obtain a given behaviour. Here, we address design constraints introduced by both functions accommodated i.e., desired operation unit cells wireless communication enabling such functionality. process for...
The realization of a programmable metasurface, enabled by custom application-specific integrated circuit (ASIC), is presented in this paper. ASIC used to provide an adaptive complex impedance load each the metasurface unit cells. Various technology nodes are analyzed for implementation tunable loading elements before one selected final implementation, which four loads placed within circuit, and controlled two digital-to-analog converters. Furthermore, ASICs populate back form mesh network...
Abstract In this work we study in-depth the antireflection and filtering properties of ultrathin-metal-film-based transparent electrodes (MTEs) integrated in thin-film solar cells. Based on numerical optimization MTE design experimental characterization perovskite cell (PSC) samples, show that reflection visible spectrum can be strongly suppressed, contrast to common belief (due compact metal layer). The optical loss optimized electrode (~ 2.9%), composed a low-resistivity an insulator, is...
In this work we present a method for fabricating three dimensional, ultralight and flexible millimeter metamaterial units using commercial household 3D printer. The is low-cost, fast, eco-friendly accessible. particular, use the Fused Deposition Modeling printing technique fabricate conductive Spilt Ring Resonators (SRRs) in free-standing form. We characterized samples experimentally through measurements of their spectral transmission, standard rectangular microwave waveguides. Our findings...
Interaction of intense terahertz (THz) waves with graphene based modulation devices holds great potential for the optoelectronic applications future. Here, we present a thin film graphene-based THz perfect absorbing device whose absorption and phase characteristics can be modulated through self-actions in subps time scale. The consists single-layer placed on an ionic liquid substrate, back-plated by metallic back-reflector, doping level mediated electrostatic gating. We experimentally record...
We present a new approach to Extended Reality (XR), denoted as iCOPYWAVES, which seeks offer naturally low-latency operation and cost effectiveness, overcoming the critical scalability issues faced by existing solutions. iCOPYWAVES is enabled emerging PWEs, recently proposed technology in wireless communications. Empowered intelligent (meta)surfaces, PWEs transform wave propagation phenomenon into software-defined process. leverage to: i) create, then ii) selectively copy scattered RF...