Ge/Si compact photodetector with inductive gain peaking

Abstract

Receiver subsystems in optical communication systems demand low power consumption and high-speed data transmission, which requires the use of high-sensitivity photodetectors to detect weak optical signals and maintain signal integrity accurately. Integrating these photodiodes directly and efficiently into silicon photonics platforms remains a significant challenge. This work focuses on the design and analysis of a vertically coupled germanium-on-silicon photodetector with doping-based performance optimization and inductive bandwidth enhancement. Two main approaches were explored: (1) numerical simulations evaluating the impact of different doping profiles on the photodetector’s frequency response, and (2) experimental validation using a commercial photodetector integrated with custom-designed compensation inductors. The gain-peaking technique improved simulated bandwidth from 39.9 GHz to 62 GHz, corresponding to a relative increase of 55.38%.