增益平坦度是衡量光纤通信中喇曼光纤放大器的关键参数之一。文章从级联光纤实现喇曼增益谱平坦技术的分析理论入手, 改进了实现喇曼增益谱平坦的约束条件, 利用Matlab分析了光纤损耗对RFA增益谱平坦度的影响。结果表明: 在喇曼光纤放大器系统中, C波段各个光之间不同的损耗系数是影响增益平坦度的关键因素, 即信号光之间损耗系数的不同会引起喇曼光纤放大器的增益平坦度劣化, 各个被放大信号光之间的损耗系数相差越大, 则增益平坦度越差。

Based on the theoretical analysis for realizing the Raman gain spectrum flattening technique, the constraints of Raman gain spectrum flatness were improved. Matlab was used to analyze the effects of fiber loss on the flatness of gain spectrum of RFA. The results show that: in the Raman fiber amplifier system, different loss coefficient between each light in C-band is one of the key factors of gain flattening, which means different loss coefficient between the signal lights can cause the deterioration of the gain flatness of Raman fiber amplifier, the loss coefficient difference of each signal light is bigger, and the gain flatness of Raman fiber amplifier is greater.