A Stochastic Modeling of the Gain in Waveguide Avalanche Photodetectors (WG-APDs)

Waveguide photodetectors are considered as a promising candidate for high speed photodetection where the tradeoff between the transit time bandwidth and the quantum efficiency is overcome as the incident optical signal and the photogenerated carriers move in perpendicular directions. In WG-Avalanche Photodetectors (WG-APDs), the avalanche multiplication gain enhances the photocurrent of the photodiodes. In these photodiodes, the inaccuracies in the ionizations coefficients of the photogenerated electrons and holes and in the dimensions of the multiplication layer affect the multiplication gain of the device and its functionality. In this paper, a stochastic analysis of the multiplication gain of the WG - separated absorption multiplication-APDs is presented, that is based on Monte Carlo simulations and on the frequency response of the photodetector.