High-sensitivity 10 Gbps Ge-on-Si photoreceiver operating at lambda approximately 1.55 microm

We present a high-sensitivity photoreceiver based on a vertical- illumination-type 100% Ge-on-Si photodetector. The fabricated p-i-n photodetector with a 90 microm-diameter mesa shows the -3 dB bandwidth of 7.7 GHz, and the responsivity of 0.9 A/W at lambda approximately 1.55 microm, corresponding to the external quantum efficiency of 72%. A TO-can packaged Ge photoreceiver exhibits the sensitivity of -18.5 dBm for a BER of 10(-12) at data rate of 10 Gbps. This result proves the capability of a cost-effective 100% Ge-on-Si photoreceiver which can readily replace the III-V counterparts for optical communications.