Nanophotonics (Dec 2022)

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

  • Nishida Kentaro,
  • Sasai Koki,
  • Xu Rongyang,
  • Yen Te-Hsin,
  • Tang Yu-Lung,
  • Takahara Junichi,
  • Chu Shi-Wei

DOI
https://doi.org/10.1515/nanoph-2022-0597
Journal volume & issue
Vol. 12, no. 1
pp. 139 – 146

Abstract

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In this paper, we theoretically and experimentally demonstrated photothermal nonlinearities of both forward and backward scattering intensities from quasi-perfect absorbing silicon-based metasurface with only λ/7 thickness. 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 at the resonance wavelength of the metasurface, 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.

Keywords