A5101896166- Metamaterials and Metasurfaces Applications
- Plasmonic and Surface Plasmon Research
- Photonic and Optical Devices
- Photonic Crystals and Applications
- Advanced Antenna and Metasurface Technologies
- Mechanical and Optical Resonators
- Gold and Silver Nanoparticles Synthesis and Applications
- Quantum optics and atomic interactions
- Nanowire Synthesis and Applications
- Advanced Fiber Laser Technologies
- Optical Coatings and Gratings
- Antenna Design and Analysis
- Orbital Angular Momentum in Optics
- Advanced Fiber Optic Sensors
- Electromagnetic Scattering and Analysis
- Thermal Radiation and Cooling Technologies
- Quantum Information and Cryptography
- Optical Network Technologies
- Nonlinear Optical Materials Studies
- Optical and Acousto-Optic Technologies
- Photovoltaic Systems and Sustainability
- Advanced Photonic Communication Systems
- Quantum and Classical Electrodynamics
- Advanced Materials and Mechanics
- Near-Field Optical Microscopy
Stanford University
2016-2022
Université de Bordeaux
2013-2017
Centre National de la Recherche Scientifique
2011-2017
Laboratoire Photonique, Numérique et Nanosciences
2013-2017
Institut d’Optique Graduate School
2015
Laboratoire Charles Fabry
2010-2012
Université Paris-Sud
2011
We show that silicon-based metagratings capable of large-angle, multifunctional performance can be realized using inverse freeform design. These devices consist nonintuitive nanoscale patterns and support a large number spatially overlapping optical modes per unit area. The quantity modes, in combination with their optimized responses, provides the degrees freedom required to produce high-efficiency devices. To demonstrate power versatility our approach, we fabricate efficiently deflect...
A key challenge in metasurface design is the development of algorithms that can effectively and efficiently produce high-performance devices. Design methods based on iterative optimization push performance limits metasurfaces, but they require extensive computational resources limit their implementation to small numbers microscale We show generative neural networks train from images periodic, topology-optimized metagratings high-efficiency, topologically complex devices operating over a...
Metasurfaces are ultrathin optical elements that highly promising for constructing lightweight and compact systems. For their practical implementation, it is imperative to maximize the metasurface efficiency. Topology optimization provides a pathway pushing limits of efficiency; however, topology methods have been limited design microscale devices due extensive computational resources required. We introduce new strategy optimizing large-area metasurfaces in computationally efficient manner....
Abstract Metasurfaces are thin‐film optical devices for tailoring the phase fronts of light. The extension metasurfaces to multiple wavelengths has remained a major challenge, and existing design techniques do not yield with high efficiency. This study reports new method, based on inverse freeform optimization, that enables high‐efficiency, multiwavelength metasurfaces. Using an iterative optimization solver, this incorporates wavelength responses into wavelength‐scale domains in...
We derive a closed-form expression that accurately predicts the peak frequency-shift and broadening induced by tiny perturbations of plasmonic nanoresonators without critically relying on repeated electrodynamic simulations spectral response nanoresonator for various locations, sizes or shapes perturbing objects. The force present approach, in comparison with other approaches same kind, is derivation supported mathematical formalism based rigorous normalization resonance modes consisting...
By placing a quantum emitter in the mouths of nanogaps consisting two metal nanoparticles nearly contact, significant increases emission rate are obtained. This mechanism is central design modern plasmonic nanoantennas. However, due to lack general knowledge on balance between different decay rates (emission, quenching, and absorption), light-emitting devices based performed rather hazardous fashion; intuitive recipes do not presently exist. With accurate simple closed-form expressions for...
Semiconducting nanostructures are promising as components in high-performance metasurfaces. We show that single-crystal silicon can be used to realize efficient metasurface devices across the entire visible spectrum, ranging from 480 700 nm. Alternative forms of silicon, such polycrystalline and amorphous suffer higher absorption losses do not yield metasurfaces this wavelength range. To demonstrate, we theoretically experimentally characterize resonant scattering peaks individual...
Anomalous refraction is a form of extreme waveform manipulation that can be realized with artificially structured nanomaterials, such as metamaterials or metasurfaces. While this phenomenon has been previously demonstrated for select input and output angles, its generalization to arbitrary angles high efficiencies remains challenge. In study, we show periodic dielectric metasurfaces support ultra-high-efficiency anomalous nearly combinations incident outgoing (>90% efficiency up 50°). Both...
Light emitters or scatterers embedded in stratified media may couple energy to both free space modes and guided of the structure. For a comprehensive analysis, it is important evaluate angular intensity distribution free-space excited such systems. In present work, we propose an original method based on Lorentz-reciprocity theorem efficiently calculate radiation diagrams with high accuracy from sole knowledge near-field around scatterers. Compared conventional near-to-far field...
Topology optimization is a powerful iterative inverse design technique in metasurface engineering and can transform an initial layout into high-performance device. With this method, devices are optimized within local phase space, making the identification of suitable geometries essential. In Letter, we examine impact geometric on performance large-angle (75 deg) topology-optimized metagrating deflectors. We find that when conventional designs based dielectric nanoposts used as layouts for...
Dielectric metasurfaces are ultra-thin devices that can shape optical wavefronts with extreme control. While an assortment of materials possessing a wide range dielectric constants have been proposed and implemented, the minimum contrast required for to achieve high-efficiency performance, given device function feature size constraint, is unclear. In this Article, we examine impact material selection on metasurface efficiency at frequencies. As model system, design transmissive, single-layer...
Abstract Conventional phased‐array metasurfaces utilize subwavelength‐scale nanoparticles or nanowaveguides to specify spatially‐dependent amplitude and phase responses light. An alternative design strategy is based on freeform inverse optimization, in which wavelength‐scale elements are designed produce devices that possess exceptionally high efficiencies. In this report, we theoretically analyze the physical mechanisms enabling efficiency freeform‐based periodic metasurfaces, i.e.,...
Hybrid nanostructures composed of both typical atoms and metallic nanoparticles such as nanoresonators host a variety optical properties. Analytical modeling is used to derive the responses materials in computationally feasible way.
Tiny metal nanogaps may offer a unique platform for achieving extremely larger spontaneous decay rate with high quantum yield.
We propose a semianalytical formalism based on time-domain resonant-mode-expansion theory to analyze the ultrafast temporal dynamics of optical nanoresonators. compare theoretical predictions with numerical data obtained FDTD method, which is commonly used experiments in field. The comparison reveals that present (i) provides deeper physical insight onto response and (ii) much more computationally efficient. Since its implementation easy, formalism, albeit approximate, can be advantageously...
One path to quantum information processing involves light-matter interaction, such as light in a photonic-crystal waveguide coupled cloud of ultracold alkali atoms. However, actually implement system, it is crucial increase the coupling strength beyond what presently achievable. The authors explain design requirements achieve large by decreasing group velocity an edge mode hybrid-clad waveguide, allowing photons ``slow light'' interact with trapped cold atoms robust, chip-integrated setting.
We use the Bloch-mode orthogonality to derive simple closed-form expressions for scattering coefficients at an interface between two periodic media, a computationally-challenging electromagnetic problem that can be solved only with advanced numerical tools. The derivation relies on assumptions is illuminated by fundamental Bloch mode and media have slightly different geometrical parameters. Through comparison fully-vectorial three-dimensional computations, analytical are shown highly...
By constructing a pillar–cone double-structure surface on SiC, near-perfect absorption is realized in the whole reststrahlen band of SiC.
We experimentally demonstrate a 400 Gbit/s optical communication link utilizing wavelength-division multiplexing and mode-division for total of 40 channels. This utilizes novel, to the best our knowledge, GHz frequency comb source based on chip-scale photonic crystal resonator. Silicon-on-insulator inverse-designed 4 × multiplexer structures enable fourfold increase in data capacity. show less than -10 dBm receiver power error-free transmission 34 out channels using PRBS31 pattern.
One--dimensional (1D) infinite periodic systems exhibit vanishing group velocity and diverging density of states (DOS) near band edges.However, in practice, have finite sizes inevitably this prompts the question whether helpful physical quantities related to systems, such as that is deduced from structure, remain relevant systems.For instance, one may wonder how DOS divergence can be approached with systems.Intuitively, expect implementation larger DOS, or equivalently smaller velocities,...
Axicon lenses are versatile optical elements that can convert Gaussian beams to Bessel-like beams. In this letter, we demonstrate axicons operating with high efficiencies and at large angles be produced using high-contrast, multilayer gratings made from silicon. Efficient beam deflection of incident monochromatic light is enabled by higher-order modes in the silicon structure. Compared diffractive devices low-contrast materials such as dioxide, our have a relatively low spatial profile,...
We implement robustness control in topology-optimized metasurfaces and show that robust are relatively insensitive to geometric erosion dilation. also explore the physical mechanisms enabling through a coupled mode analysis.