研究了同向泵浦分布式拉曼放大器(DRA)中泵浦－信号间的四波混频(FWM)效应。基于分段求和法，导出了不同零色散波长光纤组成的前向泵浦DRA中FWM功率的计算公式。考虑受激拉曼放大的情况下，数值模拟了DRA中FWM引起的信道串扰随光纤传输距离的演变，以及FWM与光纤零色散波长之间的关系。理论分析了色散补偿光纤(DCF)对FWM串扰的抑制效应。计算结果表明，在采用非零色散位移光纤(NZDSF)作为传输介质的DRA中，泵浦－信号间存在着较强的FWM效应，严重影响了密集波分复用(DWDM)系统的传输性能。引入适量DCF，不仅能降低DRA中FWM引起的信道串扰，还可有效消除色散导致的波形失真。

Pump-signal four wave mixing(FWM)in co-pumped distributed Raman amplifier(DRA)is studied. Also,the calculation formula for the FWM power in DRA with nonuniform zero dispersion wavelengths is derived based on the method of sum of subsections. FWM induced channel crosstalk distribution along the transmission fiber and the interrelationship between FWM and the location of the fiber zero dispersion wavelength are simulated numerically. The suppression effect on FWM by introducing proper dispersion compensation fiber(DCF)is analyzed theoretically. Computational results show that,strong pump-signal FWM effect occurs in DRA with nonzero dispersion shifted fiber(NZDSF)as gain medium,which seriously degrades transmission performance of the dense wavelength division multiplexing(DWDM)system. Introductionm of appropriate DCF can not only reduce FWM channel crosstalk but also eliminate the waveform distortion induced by dispersion effectively.