A5054748851- Metamaterials and Metasurfaces Applications
- Plasmonic and Surface Plasmon Research
- Photonic Crystals and Applications
- Photonic and Optical Devices
- Advanced Antenna and Metasurface Technologies
- Optical Coatings and Gratings
- Gold and Silver Nanoparticles Synthesis and Applications
- Orbital Angular Momentum in Optics
- Near-Field Optical Microscopy
- Thin-Film Transistor Technologies
- Antenna Design and Analysis
- Silicon and Solar Cell Technologies
- Silicon Nanostructures and Photoluminescence
- Quantum Information and Cryptography
- Electromagnetic Scattering and Analysis
- Mechanical and Optical Resonators
- Terahertz technology and applications
- Thermal Radiation and Cooling Technologies
- Quantum optics and atomic interactions
- Random lasers and scattering media
- Advanced Fiber Laser Technologies
- Quantum Dots Synthesis And Properties
- Liquid Crystal Research Advancements
- Spectroscopy and Quantum Chemical Studies
- Nonlinear Optical Materials Studies
Karlsruhe Institute of Technology
2016-2025
Institute of Nanotechnology
2021-2025
University of Nottingham
2024
University of Maryland, College Park
2021
Joint Quantum Institute
2021
National Institute of Standards and Technology
2021
Leibniz Institute of Photonic Technology
2021
EdgeWave (Germany)
2020
Moscow State Pedagogical University
2019
Martin Luther University Halle-Wittenberg
2009-2019
Titanium dioxide (TiO2) displays photocatalytic behavior under near-ultraviolet (UV) illumination. In another scientific field, it is well understood that the excitation of localized plasmon polaritons on surface silver (Ag) nanoparticles (NPs) causes a tremendous increase near-field amplitude at well-defined wavelengths in near UV. The exact resonance wavelength depends shape and dielectric environment NPs. We expected TiO2 would be greatly boosted if gets assisted by enhanced amplitudes...
We experimentally demonstrate a three-dimensional chiral optical metamaterial that exhibits an asymmetric transmission for forwardly and backwardly propagating linearly polarized light. The observation of this novel effect requires composed metaatoms without any rotational symmetry. Our analysis is supported by systematic investigation the matrices arbitrarily complex, lossy media allows deriving simple criterion in arbitrary polarization base. Contrary to physical intuition, general...
By relying on an advanced Jones calculus, we analyze the polarization properties of light upon propagation through metamaterial slabs in a comprehensive manner. Based symmetry considerations, show that all periodic metamaterials may be divided into five different classes only. It is shown each class differently affects transmitted and sustains eigenmodes. We how to deduce these from considerations provide simple algorithm can applied decide which given belongs by measuring only intensities.
Metamaterial-based perfect absorbers promise many applica- tions. Perfect absorption is characterized by the complete suppression of transmission and reflection dissipation incident energy absorptive meta-atoms. A certain spectrum usually assigned to a bulk medium serves as signature respective material. Here we show how use graphene flakes building blocks for absorbers. Then, an absorbing meta-atom only consists molecular monolayer placed at appropriate distance from metallic ground plate....
Terahertz time domain spectroscopy and rigorous simulations are used to probe the coupling between a dark bright plasmonic eigenmode in metamaterial with broken symmetry. The consists of two closely spaced split ring resonators that have their gaps nonidentical positions within ring. For normal incidence fixed polarization both lowest-order eigenmodes can be excited, although one them has regarded as since is prohibited because symmetry constraints. Emphasis this work put on systematic...
We experimentally demonstrate at terahertz frequencies that a planar metamaterial exhibits spectral response resembling electromagnetically induced transparency. The unit cell consists of split ring surrounded by another closed where their dimensions are such excitable lowest order modes have identical resonance but very different lifetimes. Terahertz time-domain spectroscopy verifies the interference these two resonances results in narrow transparency window located within broad opaque...
We show for the first time that a planar metamaterial, an array of coupled metal split-ring resonators with unit cell lacking mirror symmetry, exhibits asymmetric transmission terahertz radiation (0.25-2.5 THz) propagating through it in opposite directions. This intriguing effect, is compatible Lorentz reciprocity and time-reversal, depends on directional difference conversion efficiency incident circularly polarized wave into one handedness, only possible lossy low-symmetry chiral...
The standard hydrodynamic Drude model with hard-wall boundary conditions can give accurate quantitative predictions for the optical response of noble-metal nanoparticles. However, it is less other metallic nanosystems, where surface effects due to electron density spill-out in free space cannot be neglected. Here we address fundamental question whether description plasmonics necessarily requires a fully quantum-mechanical ab initio approach. We present self-consistent (SC-HDM), both ground...
Metamaterial induced transparency is demonstrated using individual split ring resonators with two gaps on opposite side. For the symmetric structure, only a low quality dipolar resonance witnessed at normal incidence excited electric field along resonator gaps. Displacement of one gap from centre breaks symmetry and higher order mode, inaccessible in excited. Coherent interaction among modes forms an extremely sharp narrowband window centred directly dipole resonance. Such metamaterial could...
We study the near-field optical behavior of Fabry-Pérot resonances in thin metal nanowires, also referred to as quasi one-dimensional plasmonic nanoantennas. From eigenmodes well beyond quadrupolar order we extract both, propagation constant and reflection phase guided surface plasmon polariton with superb accuracy. The combined symmetry breaking effects oblique illumination retardation allow excitation dipole forbidden, even resonances. All measurements are supported by rigorous simulations...
A nanoantenna with balanced electric and magnetic dipole moments, known as the first Kerker condition, exhibits a directive radiation pattern zero backscattering. In principle, can provide even better directionality if higher order moments are properly balanced. Here, we study generalized condition in example of nanoring supporting quadrupole moments. Nanoring antennas well suited since both multipole be almost independently tuned to meet condition.
Abstract Metasurfaces based on quasi‐bound states in the continuum (quasi‐BICs) constitute an emerging toolkit nanophotonic sensing as they sustain high quality factor resonances and substantial near‐field enhancements. It is demonstrated that silicon metasurfaces composed of crescent shaped meta‐atoms provide tailored light‐matter interaction controlled by geometry. Significantly, this metasurface not only exhibits a fundamental quasi‐BIC resonance, but also supports higher‐order resonance...
Based on an analytic approach, we present a theoretical review the absorption, scattering, and extinction of both dipole scatterers regular arrays composed such i.e. metasurfaces. Besides offering tutorial by outlining maximum absorption limit for electrically/magnetically resonant particles/metasurfaces, give educative analytical approach to their analysis. Moreover, put forward analysis two known alternatives in providing perfect absorbers out electrically or magnetically metasurfaces; one...
Photonic time crystals are artificial materials whose electromagnetic properties uniform in space but periodically vary time. The synthesis of such and experimental observation their physics remain very challenging due to the stringent requirement for modulation material volumetric samples. In this work, we extend concept photonic two-dimensional structures -- metasurfaces. We demonstrate that time-varying metasurfaces not only preserve key physical despite simpler topology also host common...
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.
We numerically study the spectral response of 'U'-shaped split-ring-resonators at normal incidence with respect to resonator plane. Based on evaluation near-field patterns resonances and their geometry-dependent positions, we obtain a comprehensive consistent picture origin. conclude that all can be understood as plasmonic increasing order entire structure. In particular, for an electrical field polarized parallel gap so-called LC-resonance corresponds fundamental mode and, contrary earlier...
We introduce a technique to retrieve effective metamaterial parameters for arbitrary angles of incidence. It employs the complex reflection and/or transmission coefficients finite slab. Explicit expressions both polarizations are derived and constraints be met obtaining unique solutions discussed. The method is applied fishnet structure. turns out that all retrieved strongly depend on lateral wave vector component due complexity Thus, these mere rather than global material parameters....
Recent advances in nanolithography have allowed shifting of the resonance frequency antennas into optical and visible wavelength range with potential applications, for example, single molecule spectroscopy by fluorescence directionality enhancement molecules. Despite such great promise, analytical means to describe properties is still lacking. As phase velocity currents at frequencies metals much below speed light, standard radio (RF) antenna theory does not apply directly. For fundamental...
We consider Babinet's principle for metamaterials at optical frequencies and include realistic conditions which deviate from the theoretical assumptions of classic such as an infinitely thin perfectly conducting metal layer. It is shown that associates not only transmission reflection between a structure its complement but also field modal profiles electromagnetic resonances well effective material parameters---a critical concept metamaterials. Also playing important role in antenna design,...
We map in real space and by purely optical means near-field information of localized surface plasmon polariton (LSPP) resonances excited nanoscopic particles. demonstrate that careful polarization control enables apertureless scanning microscopy (aSNOM) to image dipolar quadrupolar LSPPs the bare sample with high fidelity both amplitude phase. This establishes a routine method for situ plasmonic other resonant structures under ambient conditions.