SENSITIVITY VARIABLE WAVEGUIDE TYPE SEMICONDUCTOR LIGHT-RECEIVING ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a light-receiving element with a wide dynamic range and a low distortion characteristic for an optical subscriber-related module at low cost. SOLUTION: In a light-receiving element 10 of optical attenuate integrated waveguide type, a waveguide light-receiving region 12 and a optically attenuated region 14 at the front stage of the light-receiving element region are integrated into a monolithic state. The light-receiving element is constituted of a lower InP clad layer 18, an optical waveguide layer 20, an upper InP clad layer 22, and a GaInAs contact layer 24 formed sequentially on an n-InP substrate 16. In this case the light-receiving element region 12 and the optically attenuated region 14 are separated by a separation groove 26. A GaInAsP intermediate layer 32 with a bandgap energy of 1.0 eV and a thickness of 5 nm is formed between the upper InP clad layer 22 with a bandgap energy of 1.35 eV and a GaInAsP waveguide layer 20b with a bandgap energy of 0.85 eV.