Biasing effects on the characteristics and the optimization of mushroom waveguide photodetectors (WGPDs)

Abstract

Waveguide photodetectors (WGPDs) are considered a leading candidate to overcome the bandwidth-quantum efficiency trade-off as the flow of the photon and carrier fluxes are perpendicular to each other enabling high date rate applications. Mushroom-WGPD was proposed to overcome the trade-off between the capacitance of the photodetector and the contact resistance. In this paper, an extended calibrated circuit model for mushroom-WGPD, including the effect of the biasing of the photodetector, is presented so resulting in the feasibility of a complete circuit simulation of the entire photoreceiver circuit. The effects of the biasing over the performance of Mushroom-WGPDs have been explored for different loads and different dimensions of the device. Based on the studies of different parameters for design and materials, optimization has been performed for the mushroom-WGPD. With this optimization, the optimal values of the thickness of the absorption layer to produce the highest bandwidth of the photodetector are obtained for different biasing values. These optimizations are performed for different areas of the photodetector and also for different load resistors, and they result in a significant improvement in the performance of the mushroom-WGPDs.