反向抽运光纤拉曼放大器阈值的数值分析

Numeric Simulation of Threshold Characteristics of Backward-pumped Fibre Raman Amplifier

为分析反向抽运光纤拉曼放大器的阈值特性,基于已有的耦合微分方程,采用龙格库塔法和打靶法相结合的算法,数值模拟了反向抽运光纤拉曼放大器中信号光功率沿光纤的演变过程,在此基础上根据实际情况推导出反向抽运光纤拉曼放大器的阈值公式,并详细分析了各个参数对反向抽运光纤拉曼放大器阈值特性的影响,结果表明,初始信号光功率、光纤有效长度、拉曼增益系数增加,阈值就会减小;光纤有效面积越大,阈值越大。

In order to analyze the threshold characteristics of backward-pumped fibre Raman amplifier（FRA）,signal power distribution along a fibre with shooting method and Runge-Kutta method of the coupling equations of backward-pumped FRA was provided.Then,the theoretical expression of backward-pumped FRA＇s was obtained with considering the practical factors,and the effects of every parameter on threshold of backward-pumped FRA were investigated.It is indicate that,the threshold will decrease when the initial signal power or the effective fibre length or Raman gain coefficient increase,and the threshold will increase when the efficient area of fibre increases.