非线性高双折射阶跃光纤中单一频率传输区域调制不稳定性

利用光脉冲在高双折射非线性光纤中传播时所遵守的相干耦合非线性薛定谔方程,研究了单一频率的线偏振光,当偏振方向沿两个双折射轴的分量强度相等时,其在阶跃式光纤中反常色散区和正常色散区所产生的调制不稳定性。结果表明,调制不稳定性这一过程不仅产生在反常色散区,而且产生在正常色散区,对于阶跃式光纤,矢量调制不稳定性还随级数不同发生变化。并且,反常色散区产生的增益谱不同于正常色散区,较之多一个增益谱区域。

Modulation instability of single frequency propagation regime in nonlinear high birefingent step-wise decreasing fiber

The coherently coupled nonlinear Schrdinger(NLS) equation of the propagation of a light pulse in a fiber was utilized.Modulation instability of linearly polarized light with single frequency in a nonlinear birefingent step-wise decreasing dispersion fiber was discussed not only in anomalous dispersion regime but also in normal dispersion regime when the intensities along the two-birefringence axes were equal.The results show,when a linearly polarized wave propagates in a single mode fiber,that the procedure occurred not only in the normal dispersion regime but also in abnormal dispersion regime,and the gain spectra will change with token distance series m's increasing.Especially,two regimes where the gain spectra exist were found in anomalous dispersion regime not in normal dispersion regime.