27 GHz Silicon-Contacted Waveguide-Coupled Ge/Si Avalanche Photodiode

We report a silicon-contacted Ge/Si avalanche photodiode with RF gain of 11 and a bandwidth of 27 GHz at -12 V operating at 1310 nm. The device is fabricated in an established Si photonics platform without additional process complexity and contacts only on Si. Wafer-scale performance data are presented confirming the reproducibility and the manufacturability of the device. Wide open eye diagrams are demonstrated for 25, 40, and 50 Gbps data-rates. The demonstration of such avalanche photodiode shows great potential for improving optical link margins for optical transceivers operating at 400 Gb/s and beyond.