Photoresponse analysis for uni-traveling-carrier photodiodes

A photodetector is a key component in an optical fiber communications system and in optical signal conversion. It is also an important part of the integrated optoelectronic receiver. Its performance directly influences the performance and design requirements of the entire system. This paper compares the structural differences and characteristic differences between the UTC-PD and PIN-PD. The operation mechanism of the UTC-PD is discussed, and the characteristics of the UTC-PD is analyzed using Poisson´s equation and the continuity equation of current. The results clearly show that the separation of the absorption layers and collection layers are key factors that determine UTC-PD performance. This paper also presents some approaches to improve UTC-PD performance.