High Performance Ge-on-Si Photodetector With Optimized Light Field Distribution by Dual-Injection

This paper proposed a photodetector with a dual-injection structure. Input power is splitted into two beams by a 3 dB beam splitter at the incident end and then coupled into the photodetector, which can make the light field distribution in the germanium absorption layer more uniform. With the same active area structure, the responsivity of the dual-injection structure can be increased by 45.73% at 108.33 mW, the saturated optical power could be induced by 44.76%, and the bandwidth can be improved by 6.74 GHz at 20 mW comparing with the single-injection structure. The dual-injection structure improves the performance of the device without increasing the complexity.