Achievement of shot-noise-limited sensitivity and 50-dB dynamic range by photon-counting receiver using Si avalanche photodiode

A photon-counting receiver using a Si-avalanche photodiode has been constructed. The circuit noise and the dark-current and excess noises of the APD are almost perfectly removed from the receiver output by the level discrimination process. The shot-noise-limited receiver sensitivity, an overall efficiency of 58 percent, and a dynamic range of 50 dB have been achieved.