Compact and low-loss liquid crystal loaded Mach-Zehnder optical switch based on Si wire waveguide

Abstract

We demonstrate a compact and low-loss liquid crystal loaded Si wired Mach-Zehnder (MZ) optical switch in the in-plane switching mode. The device is configured with a simple structured MZ interferometer in which one side of phase-shifter-electrodes is placed on the MZ-island-like area. A device with a 100-µm-long phase shifter has small footprint of within 300 × 80 µm 2 and exhibits quite low device losses and relatively smooth spectra with a voltage-length product of ∼0.4 V·mm. The thermal characteristics of the device are also evaluated and the device is found to be operable until at least 60°C.