Search results for "all-dielectric metasurface"

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Finite-Size and Illumination Conditions Effects in All-Dielectric Metasurfaces

2022

Dielectric metasurfaces have emerged as a promising alternative to their plasmonic counterparts due to lower ohmic losses, which hinder sensing applications and nonlinear frequency conversion, and their larger flexibility to shape the emission pattern in the visible regime. To date, the computational cost of full-wave numerical simulations has forced the exploitation of the Floquet theorem, which implies infinitely periodic structures, in designing such devices. In this work, we show the potential pitfalls of this approach when considering finite-size metasurfaces and beam-like illumination conditions, in contrast to the typical infinite plane-wave illumination compatible with the Floquet t…

All-dielectric metasurfaces BIC Multipolar decomposition T-matrixComputer Networks and CommunicationsHardware and ArchitectureControl and Systems Engineeringall-dielectric metasurfaces; multipolar decomposition; T-matrix; BICSignal ProcessingPhysics::OpticsSettore ING-INF/02 - Campi ElettromagneticiElectrical and Electronic EngineeringElectronics
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Tailoring Third-Harmonic Diffraction Efficiency by Hybrid Modes in High-Q Metasurfaces

2021

Metasurfaces are versatile tools for manipulating light; however, they have received little attention as devices for the efficient control of nonlinearly diffracted light. Here, we demonstrate nonlinear wavefront control through third-harmonic generation (THG) beaming into diffraction orders with efficiency tuned by excitation of hybrid Mie-quasi-bound states in the continuum (BIC) modes in a silicon metasurface. Simultaneous excitation of the high-Q collective Mie-type modes and quasi-BIC modes leads to their hybridization and results in a local electric field redistribution. We probe the hybrid mode by measuring far-field patterns of THG and observe the strong switching between (0,-1) and…

bound states in the continuumMechanical Engineeringall-dielectric metasurface bound states in the continuum high-Q metasurface hybrid mode Third-harmonic diffraction wavefront controlhybrid modeBioengineeringSettore ING-INF/02 - Campi Elettromagnetici02 engineering and technologyGeneral Chemistryhigh-Q metasurface021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural scienceswavefront controlall-dielectric metasurface0103 physical sciencesThird-harmonic diffractionThird-harmonic diffraction; all-dielectric metasurface; bound states in the continuum; high-Q metasurface; hybrid mode; wavefront controlGeneral Materials Science010306 general physics0210 nano-technology
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