Ultrafast optical switching of terahertz metamaterials fabricated on ErAs/GaAs nanoisland superlattices

Opt Lett. 2007 Jun 15;32(12):1620-2. doi: 10.1364/ol.32.001620.

Abstract

We demonstrate optical switching of electrically resonant terahertz planar metamaterials fabricated on ErAs/GaAs nanoisland superlattice substrates. Photoexcited charge carriers in the superlattice shunt the capacitive regions of the constituent elements, thereby modulating the resonant response of the metamaterials. A switching recovery time of 20 ps results from fast carrier recombination in the ErAs/GaAs superlattice substrates.