抽运饱和及信道间受激拉曼散射效应对反向抽运分布式光纤拉曼放大器增益谱的影响

在宽带密集波分复用 (DWDM )系统中 ,后向抽运分布式光纤拉曼放大器 (B DFRA)会引入在小信号条件下无需考虑的两种效应 :抽运饱和效应 (PS)使拉曼增益减小 ;拉曼放大使信道间受激拉曼散射 (SRS)效应增强 ,产生附加拉曼倾斜效应 (ART)。将后向抽运分布式光纤拉曼放大器的增益谱分解为拉曼抽运的放大作用和信道间受激拉曼散射效应产生的倾斜作用 ,通过对各种工作条件下实际后向抽运分布式光纤拉曼放大器增益谱的优化计算 ,研究了抽运饱和效应和附加拉曼倾斜效应对后向抽运分布式光纤拉曼放大器增益谱的影响。计算发现抽运饱和效应取决于信道输出功率 ,附加拉曼倾斜效应由信道输入功率和输出功率共同决定 ,进而通过抽运饱和效应和附加拉曼倾斜效应的大小可以将后向抽运分布式光纤拉曼放大器的工作条件划分为三个区域 ,并讨论了不同工作条件下后向抽运分布式光纤拉曼放大器的简化分析方法

Impact of Pump Saturation and SRS between Channels on B-DFRA Gain Spectrum

In broad band density wavelength dense multiplexing (DWDM) systems, there are two effects impacting the gain spectrum of backward pumped distributed fiber Raman amplifier (B DFRA): pump saturation (PS) reduce Raman gain; Raman amplification produces stimulated Raman scattering (SRS) between channels larger, leading to additional Raman tilt (ART). In this paper, the gain spectrum of a B DFRA is divided by two contributions: Raman amplification by Raman pump and channel power tilt by SRS between signal channels. By optimization of a B DFRA in various input signal power condition and gain level, the impacts of PS and ART on the gain spectrum of B DFRA are analyzed. Calculation shows that PS is dominated by input signal power only; ART is dominated by both input signal power and output signal power. By the results of PS and ART, the work condition of B DFRA can be divided into three regions. Possible simplification in B DFRA analysis in each region is discussed.