受激布里渊散射(SBS)是光纤中一种非常重要的非线性效应，并且其阈值较低，在光纤中极易产生，造成光纤系统中作为信号载体的入射光的能量损耗，并且其后向散射光有可能对光源造成损害，从而限制进入光纤功率及系统的传输距离。从受激布里渊散射的基本原理出发，分析讨论了受激布里渊散射阈值与光源调制频率、光源线宽、光纤长度及损耗系数的关系。设计并搭建了实验系统，实际测量得到了19.5 km的G.653光纤受激布里渊散射阈值，实验结果与理论计算吻合。

Stimulated brillouin scattering (SBS) is one of important nonlinear effects in fiber communication system or optical fiber sensing system. SBS can be brought easily in fiber for its low threshold, inducing power loss of incident laser in fiber system which is engaged as signal carrier, damaging laser source for backward scattered light caused by SBS, limiting laser power and transmitting distance of fiber system. Basing on the theory of SBS, the relation of SBS threshold with modulating frequency of laser source, linewidth of laser source, length of fiber and coefficient of loss is analyzed. The SBS threshold of 19.5 km G.653 fiber is measured by experiments, and the results accord with the theory calculation.