针对光纤通信中密集波分复用系统各信道的在线平坦光放大这一光通信问题,提出利用级联高非线性光纤来设计增益平坦的拉曼光纤放大器。对高非线性光纤(As-S光纤)拉曼增益谱前后沿进行线性拟合处理, 利用不同波长泵浦抽运同种光纤, 实现前放大后增益补偿, 并考虑信号光损耗不同, 在输出端得到了一个近似固定的功率输出值, 并分析了影响拉曼光纤放大器输出特性的因素。模拟结果表明: 平均增益为20.45 dB, 增益平坦度为0.15 dB。

In order to realize the flat inline amplification of all dense wavelength division multiplexing(DWDM) transmission channels in optical fiber communication systems, it was proposed to get gain-flattened Raman fiber amplifier based on cascading highly nonlinear fiber. An approximate value of output signal power at the output port was finally obtained considering different signal light losses, when the linear method was used for obtaining the Raman gain spectrum. Moreover, the average gain and gain flatness were 20.45 dB and 0.15 dB, respectively. Then, the factors for the output characteristics of Raman fiber amplifier were analyzed. Simulation results demonstrate that the designed Raman fiber amplifier has advantages of high gain, smaller gain flatness as well as simple configuration.