Thermal characterization of modified uni-traveling carrier photodetectors: insights into temperature-dependent performance metrics

Abstract

We present an approximation method to compute the temperature distribution in photodetectors under steady-state optical excitation. The derived temperature profile assesses the impact on performance metrics like quantum efficiency, bandwidth, and phase noise. Our numerical study reveals that assuming constant room temperature leads to overestimated output current and quantum efficiency and underestimated bandwidth. In contrast, a varying temperature model closely aligns with experimental values. InGaAs’s low thermal conductivity impedes heat dissipation, leading to temperature accumulation. Changing optical excitation while maintaining constant output current results in nonlinear changes in bandwidth, phase noise, and quantum efficiency. These findings aid in understanding and optimizing thermal management in photodetectors under strong optical excitations.