MODELING AND PERFORMANCE OF WAFER-FUSED RESONANT-CAVITY ENHANCED PHOTODETECTORS

In this paper, we discuss wavelength tuning and its corresponding quan tum efficiency modulated by the standing wave effects in a resonant-ca vity enhanced (RCE) photodetectors. Specific design conditions are mad e for a thin In0.53Ga0.47As (900 Angstrom) photodetector wafer-fused t o a GaAs-AlAs quarter wavelength stacks (QWS). Analytic expressions fo r the calculation of resonant wavelength and standing wave effects are derived, using a hard mirror concept of fixed phase upon reflection, and are found to agree reasonably well with the exact numerical approa ch, using a transmission matrix method. We then experimentally demonst rate that wavelength tuning as large as 140 mn and its corresponding q uantum efficiency modulated by the standing wave effects are clearly o bserved in our wafer-fused photodetectors, consistent with the predict ions. The external quantum efficiency at 1.3 mu m wavelength and absor ption bandwidth for the wafer-fused RCE photodiodes integrated with an amorphous Si-SiO2 dielectric mirror are measured to be 94% and 14 mn, respectively. This technique allows the formation of multichannel pho todetectors with high quantum efficiency and small crosstalk, suitable for application to wavelength demultiplexing and high-speed, high-sen sitivity optical communication systems.