双折射光纤中拉曼效应对参量放大增益谱的影响

Raman effect on parametric amplification gain spectrum in birefringence fiber

根据激光脉冲在光纤中传输时,所满足的波动方程,导出了拉曼效应和参量放大共同作用下,在双折射光纤中所遵循的耦合模方程,并引入平行拉曼增益的洛伦兹模型,给出了输入抽运波偏振方向同双折射轴成45。时,拉曼效应和参量放大共同作用所导致的增益.讨论并分析了拉曼效应在不同色散区对参量放大增益谱的影响.结果表明在考虑拉曼效应后,使得参量放大斯托克斯波与反斯托克斯波增益谱彼此不对称;在反常色散区,产生的增益以反斯托克斯波为主,正常色散区则以斯托克斯波为主.

According to the wave equation used when the optical pulse propagation in the fiber, the nonlinear coupled equation is a deduced under the joint actions of Raman effect and parametric amplification in the birefringent, with Lorentzian model of parallel Raman gain spectrum, the gain is obtained by combining the Raman effect and the parametric amplification when the pump wave polarization is oriented at 45~ between the birefringent fiber axes. The gain spectrum is discussed as a function of the input parameters （input power, the group velocity mismatch） in different dispersion regimes. The result shows that Stokes and anti-Stokes gain spectra are asymmetric because of Raman effect. The gain appears as primarily anti-Stokes wave in anomalous dispersion regime, and Stokes wave in normal dispersion regime.