反向传输中高阶色散项的交叉相位调制不稳定性分析

对在光纤中反向传输的两束光,以包含了三、四阶色散项的耦合非线性薛定谔方程为基础,主要研究高阶色散对交叉相位调制不稳定性的影响.三阶色散对调制不稳定性不起作用,但反向传输光的群速度却对不稳定性的发生有影响;当满足一定条件时,由于四阶色散的影响,在光纤的反常色散区,交叉相位调制不稳定性发生在两个频谱区.在正常色散区,四阶色散产生了一个新的交叉相位调制不稳定性频谱区;反常色散区远离零点的频谱区的增益谱比正常色散区的增益谱更靠近零点,且两个频谱区的范围有准分离的对称关系.

Cross-Phase Modulational Instability with High-Order Dispersion for Anti-Direction Dispread

For two beams of input lights dispreading in opposite direction,the effect of third-order and fourth-order dispersion on cross-phase modulational instability based on extended nonlinear Schr dinger equation is investigated.The result shows: third-order dispersion has no effect on modulational instability,but the group speed of the anti-direction light has.Because of fourthorder dispersion,cross-phase modulational instability occurs at two spectrum regions in the abnormal dispersion regime of fiber under a certain conditions and a new spectrum region is created in the normal dispersion regime.Gain spectrum of the region far away from zero of abnormal dispersion regime is near zero than that of normal dispersion regime,and the widths of two spectrum regions have quasi-discrete symmetric relation.