Analysis of Multiplication Noise in N~+ N P Avalanche Photodiode

摘要

Avalanche photodiodes are mainly used in optical communications systems as light detectors. These devices are characterized by their high speed and internal gain, so there is no need in most cases to use an amplifier, which will reduce the bandwidth of the system. However these devices suffer from a main disadvantage, which is the high level of noise due to multiplication phenomena, and thus the minimum detectable power will be affected [1], [2], [3], [4]. In addition to multiplication noise, there is the thermal noise and shot noise. The purpose of this paper is to study and analyze the multiplication noise in these devices using the N~+ N P structure and illustrating the factors that affect the noise level such as the junction depth, device material, electric field profile, type of carrier which initiates the multiplication process.