High-speed and highly efficient Si optical modulator with strained SiGe layer

Abstract

We developed a high-speed and highly efficient depletion-type Si optical modulator (Si-MOD) with a pn junction by applying a p-type-doped strained SiGe layer, which was stacked on a lateral pn junction-type Si-MOD. We designed an optimum Si-MOD, which is one of the most efficient Si-MODs with a pn junction, and demonstrated highly efficient modulations of 0.67 and 0.81 V·cm for VπL at dc reverse bias voltages of −0.5 and −2 Vdc, respectively. We also demonstrated a high-speed operation of 25 Gbps for the Si-MOD at a wavelength of around 1.3 µm.