Silicon-Germanium Avalanche Receivers With fJ/bit Energy Consumption

Fast, low-noise and sensitive avalanche photo-receivers are needed for surging short-reach photonic applications. Limitations concerning bandwidth, throughput and energy consumption should be overcome. In this work, we comprehensively study the performance opportunities provided by avalanche p-i-n photodetectors with lateral silicon-germanium-silicon heterojunctions. Our aim is to circumvent the need for chip-bonded electronic amplifiers. In particular, we demonstrate that avalanche photodetectors based on silicon-germanium-silicon heterostructures yield reliable opto-electrical performances, with high gain-bandwidth products up to 480 GHz and low effective ionization ratios down to 0.15. Moreover, they improve power sensitivities for high-speed optical signals and have a low energy dissipation of only a few fJ per received information bit. These results pave the way for high-performing receivers for energy-aware data links, in next-generation short-distance data communications.