Simulation Study of a Monolithic III-V/Si V-Groove Carrier Depletion Optical Phase Shifter.

In this paper, we propose a new carrier depletion-type hybrid III-V/Si optical phase shifter using a n-III-V/p-Si hetero-junction, which can be fabricated with direct epitaxial growth of III-V semiconductors on Si. We numerically analyzed the performance of the III-V/Si hybrid optical phase shifter by comparing the performance in reverse bias operation with that of pure Si or III-V p-n optical phase shifters. The hybrid III-V/Si optical phase shifter showed improved modulation efficiency and lower optical loss compared to pure Si and III-V p-n optical phase shifters, owing to the large electron-induced refractive index change of III-V compound semiconductors, while avoiding the large hole-induced optical loss of III-V compound semiconductor. The simulation study suggests the feasibility of a very low voltage-length product $(V_{ {\pi }} L)$ of $0.07~\text {V}\cdot \text {cm}$ , a low insertion loss ($\alpha $) of 16 dB/cm, and a very low $\alpha ~V_{ {\pi }}L$ product close to 1 $\text {V}\cdot \text {dB}$ at $1.31~\mu $ m, which is 10 $\times$ lower than for Si p-n optical phase shifters. [ABSTRACT FROM AUTHOR]