Compact Fabry-Perot electro-optic switch based on n-ZnO/p-Si heterojunction structure

We present a hybrid waveguide-based optical switch using n-ZnO/p-Si heterojunction diode structure. The n-ZnO/p-Si vertical diode is incorporated with a Fabry-Perot microcavity to realize optical switching through electrical biasing. The ZnO layer functions as n-type transparent oxide semiconductor and waveguide cladding. Under 4V reverse bias (depletion), simulation shows a modulation depth of 5.54dB and tunable red-shift of 4nm over a cavity length of 17μm. A Fabry-Perot microcavity of 20μm length has been fabricated and measurement shows a tunable blue-shift of 0.1nm under 10V forward bias condition (accumulation).