Broadened band near-perfect absorber based on amorphous silicon metasurface.

A dielectric broadened band near-perfect absorber based on an amorphous silicon(a-Si) T-shaped nanostructure metasurface is investigated numerically and experimentally. The simultaneous suppressed transmission and reflection of the a-Si nanostructure metasurface are achieved by investigating the interference of the periodically adjustable electric dipole(ED) and magnetic dipole(MD) Mie resonances. The absorption of the a-Si nanostructure metasurface approaches the maximum of 95% in simulation and 80% in experiment with a top-hat shape in the spectral range from 580 nm to 620 nm by employing the T-shaped nanostructure. The proposed near-perfect absorber provides a new approach for expanding absorption bandwidth by integrating different nanostructures in metasurface, which is potentially applicable in nanophotonic fields of optical isolation, optical trapping and energy harvesting (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement