光发送机是光通信系统中的重要组成部分。光发送机的性能直接影响系统的传输性能,光发送机的设计也以优化其光接口指标为目的。本文简述了光发送机两种调制方式的原理,并使用Opti System搭建光纤通信系统模型,研究了两种调制方式对光纤通信系统光源的光谱特性及对系统误码的影响。 Optical transmitters are an important part of optical communication systems. The performance of the optical transmitter directly affects the transmission performance of the system. The design of the optical transmitter also aims to optimize its optical interface specifications. In this paper, the principle of two kinds of modulation methods for optical transmitters is briefly described, and Opti System is used to build the optical fiber communication system model. The effects of two modulation methods on the spectral characteristics of optical sources and their errors in the system are studied.