Nanoscale TiO_2 dielectric resonator absorbers

Abstract

We demonstrate a narrow-band plasmonic absorber based on a uniform array of nanoscale cylindrical dielectric resonators (DRs) on a metallic substrate at visible frequencies. Under a normally incident plane-wave excitation, the DRs resonate in their horizontal magnetic dipolar mode, which can be seen as localized plasmonic hot spots. Such a localized resonance also couples incident waves into surface plasmon polaritons (SPPs) bidirectionally, and perfect absorption is achieved by creating SPP standing waves. The simulation shows perfect absorption at 633 nm and 1.8% relative bandwidth with >90% absorption, while the measurement demonstrates maximum absorption of 90% at 636 nm. Both simulation and measurement results are analyzed with coupled mode theory. An additional numerical study elaborates on the dependence of absorption on the resonator size, period, and incidence angle.

Metal‐Loaded Dielectric Resonator Metasurfaces for Radiative Cooling

“…Metasurfaces based on DRs have become a hot research topic recently [17][18][19] due to their high efficiency [20] and the ability to support various resonance modes. [22] In the design proposed in this article, we utilize the magnetic dipole resonance of DRs to achieve wide-angle broadband absorption, and reciprocally, emission at wavelengths that match the IR transparency window, and thus achieve a strong passive cooling power. However, beyond beam control, optical DR metasurfaces can be further explored in various applications aiming at tailoring absorption.…”

“…However, beyond beam control, optical DR metasurfaces can be further explored in various applications aiming at tailoring absorption. [22] In the design proposed in this article, we utilize the magnetic dipole resonance of DRs to achieve wide-angle broadband absorption, and reciprocally, emission at wavelengths that match the IR transparency window, and thus achieve a strong passive cooling power.…”

All-Dielectric Color Filters Using SiGe-Based Mie Resonator Arrays

“…So far, silicon has been the material of choice for the implementation of this class of resonant dielectric particles and related meta-surfaces. Other materials of note are gallium phosphide (GaP) 30 , aluminium gallium arsenide (AlGaAs) 31 and titania (TiO2) 20,32,33,34,35 . To date, no reports have been shown in this field on silicon germanium (SiGe) alloys, despite their clear advantage of exhibiting larger refractive indices with respect to pure Si 36,37 allowing, in principle, for better light confinement.…”

Plasmonic- and dielectric-based structural coloring: from fundamentals to practical applications

“…Various materials such as TiO 2 and GaP have been evaluated as alternatives to PCFs and other structural color filters [ 38 , 121 – 124 ]. TiO 2 is a reasonable candidate; a recent report (Fig.…”