光通信用雪崩光电二极管(APD)频率响应特性研究

吸收层、电荷层和倍增层分离结构雪崩光电二极管(SACM-APD),包括InP/InGaAs、InAlAs/InGaAs和Si/Ge APD是光通信领域近年来研究的热点. 本文基于电路模型,系统比较了不同外延层厚度、不同材料以及不同结构APD的频率响应特性,重点探讨Si/Ge APD吸收层厚度、光敏面大小、寄生参数等各项参数对带宽的影响,仿真结果与实际器件实验数据相符合. 本文的研究成果对SACM-APD的优化设计具有指导意义. 关键词： SACM-APD 电路模型 频率响应

Frequency responses of communication avalanche photodiodes

In recent years, separate absorption, charge and multiplication avalanche photodiodes (SACM-APDs), including InP/InGaAs, InAlAs/InGaAs and Si/Ge APD, have drawn a lot of attention in the field of optical communication. In this paper, on the basis of the circuit model, the frequency response is studied systematically for APDs with different thicknesses of epitaxial layers, different multiplication materials and device structures. The effects of the absorption layer thickness, the dimension of the active area and the parasitic parameters on frequency response are addressed to Si/Ge APD. The simulation resuets are in good agreement with the experimental results, which indicates that the circuit model is helpful for the design optimization of APDs.