Adiabatic thermo-optic Mach–Zehnder switch

Abstract

In this Letter, we propose and demonstrate a high-speed and power-efficient thermo-optic switch using an adiabatic bend with a directly integrated silicon heater to minimize the heat capacity and therein maximize the performance of the thermo-optic switch. A rapid, $\tau =2.4\mathrm{\mu s}$ thermal time constant and a low electrical power consumption of $P_{\pi }=12.7\mathrm{mW}/\pi$-phase shift were demonstrated representing a $P_{\pi }\tau$ product of only $30.5\mathrm{mW}·\mathrm{\mu s}$ in a compact device with a phase shifter of only $\sim 10\mathrm{\mu m}$ long.