Low-Voltage Silicon Avalanche Photodiodes for Fiber Optic Data Transmission

A low-voltage silicon avalanche photodiode (APD) design packaged for fiber optic receiver applications is described. A unique epitaxial construction, compatible with conventional planar bipolar proeessing, is employed to achieve avalanche gain with high speed response, low bulk leakage current, and minimum slowtail response. The microlens optical design allows a pluggable, fiber optic interface with generous mechanical alignment tolerances.