All-optical switching based on coherent control of metasurface

In this paper, we propose a novel method to design ultrafast all-optical switchings based on the coherent perfect absorption principle of metasurface. Using the coherent interaction between two beams of coherent light and the metasurface, the absorption can be modulated between 0.3% and 98. 3%. Since no nonlinear dielectric is used, the ultrafast all-optical switching function can be achieved at arbitrary low intensity conditions. We further studied the mechanism of resonant absorption on metasurface, and analyzed the influence of geometric parameters on resonant absorption. Through time-domain simulation analysis, when the incident laser pulse duration is 40 fs, the switching response time is 82 fs, which provides a switching contrast ratio of more than 108.(c) 2023 Elsevier B.V. All rights reserved.