Analysis of noise and its characteristics in avalanche photodiode

Avalanche photodiodes (APDs) produce noise during operation, which affects the device performance. However, the previous research on its noise is mainly theoretical analysis and is only reflected as optical noise. Therefore, according to the characteristics of APD material and the mechanism of noise generation, the main noise of the device is analyzed in this paper. First, the test method of noise in APDs is established, including testing of dark noise, optical noise, and multiplication noise in high frequency bands. The main noises in APDs are 1/f noise, thermal noise, shot noise, generation recombination noise, and multiplication shot noise, and shot noise is suppressed by Fermi-Dirac distribution and Coulomb action. Second, the reliability of APDs is evaluated by measuring and analyzing the noise parameters of the device through thermal aging experiments. It is concluded that the defects introduced by thermal aging can be reflected by the change in noise, which is consistent with the results in the literature. This method can comprehensively obtain the noise in APDs, which is helpful to improve the working efficiency, life, and reliability of the device.