Temperature Dependence of Sensitivity of Avalanche Photodiode Based Optical Receiver

In the paper, the temperature dependence of the sensitivity of an avalanche-photodiode-based receiver applied in the free space optical communication link is discussed. Communication systems of this type are exposed to a wide range of operating temperatures, which markedly affect many photodiode and preamplifier parameters. The paper describes receiver sensitivity calculation, taking into consideration the temperature dependence of avalanche photodiode gain, excess noise factor, dark current and thermal noise of preamplifier resistances. Presented calculation is demonstrated on the connection of a small-area silicon APD operating in the wavelength range from 820 to 1150 nm with a transimpedance preamplifier using a bipolar junction transistor.