Ultrafast optical switching in Si-metasurfaces for wireless and space optical communication

Abstract

We demonstrate ultra-fast all-optical switching based on the implementation of a metasurface-based laser dichroic mirror design. The crystalline silicon metasurfaces with 100 nm thickness on sapphire substrates are fabricated using established processes in Si-semiconductor industry. Under weak-pump excitation, relative transmittance changes of up to 100% are possible for characteristic times ranging from 25 to 120 ps. A carrier-driven absolute amplitude modulation of over 72% is observed at 102-120 ps relaxation times. A CW 1030 nm laser's beam modulation for free space communication is verified in a laboratory environment. Show more