Ge0.5Si0.5strained‐layerpinphotodiodes, in which multiple strained layers serve as the absorption region, have been fabricated. These devices exhibit an optical response at wavelengths beyond 1.3 &mgr;m at normal incidence. The measured external quantum efficiencies at an applied bias of 4 V are 17% at 0.85 &mgr;m and 1% at 1.3 &mgr;m, respectively. Excellent electrical characteristics evidenced by the avalanche breakdown at 20 V have also been demonstrated. ©1995 American Institute of Physics.