Analysis of opto-microwave paths into a InP/InGaAs UTC-HPT

This paper presents the spatially dependent analysis of the frequency behavior of an InP/InGasAs UTC-HPT. It outlines the steps needed to perform phototransistor characterization. It starts with the design of an automated test measurement setup and the implementing of different post-processing routines for measurements de-embedding. These de-embedding techniques are then evaluated for their relative accuracy. Finally, the extracted phototransistor mapping is analyzed to evaluate the lateral spatial dependencies of the UTC-HPT's responsivity. In particular, the 1A/W 52μm wide UTC-HPT under analysis exhibits an improvement in performance in the 3μm vicinity of electrical contacts.