Guided-wave near-infrared detector in polycrystalline germanium on silicon

Using a guided wave configuration, we demonstrate a novel polyGe-on-Si heterostructure photodetector realized on a silicon-on-insulator by a low deposition temperature process. Without further detector optimization, at 1.55μm we measured wall-plug responsivities as high as 15mA∕W with an effective responsivity in excess of 300mA∕W. Device operation was demonstrated up to 2.5Gbit∕s.