10-GHz All-Optical Gate Based on a III–V/SOI Microdisk

We demonstrate an ultrafast and low-power all-optical gate in pump-probe configuration based on free-carrier- induced refractive index modulation in a 5-μm radius InP-InGaAsP microdisk heterogeneously integrated onto a silicon-on-insulator waveguide circuit. High-speed gating is obtained by extracting the carriers from the microdisk active layer by applying a reverse bias. Measured transient responses show that this gate is capable of working up to 20 GHz.