All-optical scattering control in an all-dielectric quasi-perfect absorbing Huygens metasurface

TL;DR

This paper demonstrates how photothermal effects in silicon-based metasurfaces can dynamically control scattering directionality, enabling all-optical modulation of scattering intensities for potential silicon photonic applications.

Contribution

It introduces a novel method of all-optical scattering control using photothermal nonlinearities in a silicon metasurface, both theoretically and experimentally.

Findings

Backward scattering cross-section doubles under laser irradiation.

Forward scattering cross-section reduces to half with photothermal heating.

Demonstrates all-optical dynamical control of scattering directionality.

Abstract

In this paper, we theoretically and experimentally demonstrated photothermally-induced nonlinearities of both forward and backward scattering intensities from quasi-perfect absorbing silicon-based metasurface. The metasurface is efficiently heated up by photothermal effect under laser irradiation, which in turn modulates the scattering spectra via thermo-optical effect. Under a few milliwatt continuous-wave excitation, backward scattering cross-section doubles, and forward scattering cross-section reduces to half. Our study opens up the all-optical dynamical control of the scattering directionality, which would be applicable to silicon photonic devices.