光纤拉曼放大器的带宽、增益及增益平坦度直接影响了光纤通信系统的传输质量.针对这些参数的优化,根据碲基光纤的拉曼增益谱特性提出了一种双泵浦级联碲基光纤的拉曼放大器结构.并推导了实现增益谱平坦时光纤长度和泵浦参数满足的约束条件.经过对拉曼增益谱的5次多项式拟合,更准确地反映了拉曼增益谱的信息,同时也简化了其实现增益谱平坦的条件.通过Matlab仿真分析得到,当两段光纤分别取0.339 km,0.16 km时,其最大增益为17.81 dB,增益平坦度为0.66 dB ,放大带宽为48 nm.该方案为宽带宽、高增益、增益平坦度小的拉曼光纤放大器设计提供了一种新的思路.

Bandwidth,gain and gain-flattening of Raman fiber amplifier(RFA) directly impact on the transmission quality of fiber communication system. RFA with two-pump cascade tellurite fiber was put forward that it will aim for optimizing these parameters according to the features of tellurite fiber Raman gain spectrum(RGS). And the constraints of fiber lengths and pumping parameters were derived when achieving gain-flattening. Quintic polynomial fitting on RGS can accurately reflect the information of RGS and simplify the conditions of achieving gain-flattening. Through Matlab simulation verification,when the two fibers are respectively 0.339 km and 0.16 km, the peak gain is 17.81 dB, gain-flattening is 0.66 dB, and amplified bandwidth is 48 nm. This project supplies a new approach for designing RFA with wide bandwidth, high gain and low gain-flattening.