高阶色散导致的交叉相位调制不稳定性

在考虑光纤损耗及高阶色散的情况下,以三、四阶色散项的耦合非线性薛定谔方程为基础,研究高阶色散对交叉相位调制不稳定性的影响.研究表明:三阶色散对调制不稳定性不起作用;由于四阶色散的影响,在光纤的正常、反常色散区,交叉相位调制不稳定性均发生在两个频谱区.且反常色散区两频谱区都比正常色散区的宽,反常色散区第二频谱区比正常色散区的更靠近零点.光纤损耗对增益谱的谱宽有较大影响,它使增益的谱宽变窄,且随传输距离的增大谱宽变得更窄.

Cross-Phase Modulation Instability with High-Order Dispersion

Based on extended nonlinear Schrdinger equation, the effects of third-order and fourth-order dispersion on cross-phase modulation instability (XPM) are investigated, considering the fiber loss and high-order dispersion. The results show that the third-order dispersion does not affect modulation instability. But because of fourth-order dispersion, XPM occurs at two spectrum regions in both the normal and the anomalous dispersion regimes under certain conditions. Gain spectra of the two regions of anomalous dispersion regime are larger than those of normal dispersion regime, and gain spectrum of the second region of anomalous dispersion regime is near zero than that of normal dispersion regime. The research also shows that fiber loss reduces the frequency range of the gain spectrum, and the frequency range becomes smaller with the increasing of the propagation distance.