Design and optimization of MUTC photodiodes performance under high-power operating conditions

A high-bandwidth and high-power back-illuminated modified uni-traveling-carrier photodiode (MUTC-PD) with InGaAsP/InGaAs as the main material is designed. The influence of the material and doping concentration of the collection layer and transition layer on the electric field distribution were investigated to achieve fast carrier transport. Using a miniaturized mesa diameter reduces the device’s capacitance, leading to an increase in the RC-limited bandwidth of the photodetector (PD). The thicknesses of the depletion and transition regions of the MUTC-PD are further optimized. The performance characteristics of the MUTC-PD, including internal electric field, energy band diagram, frequency response, and RF output power, are carefully studied.