五阶非线性下双脉冲相移和啁啾的解析研究

Analytical study on phase shifts and frequency chirps of double pulses in case of quintic nonlinearity

从光纤中扩展的耦合非线性薛定谔方程组出发,在同时考虑五阶非线性、脉冲间群速度失配和初始时延的情况下,忽略光纤色散效应,导出了载频不同的两高斯脉冲由于交叉相位调制所致的非线性相移和频率啁啾的解析公式。结果表明,与只有三阶非线性的情况相比,三五阶非线性的共同存在会使脉冲间群速度失配,且初始时延对脉冲的非线性相移和频率啁啾会产生更为综合和复杂的影响。该研究在光开关器件和频率转换等方面有一定的指导意义。

Starting from the extended coupled nonlinear Schrdinger equations in optical fibers,neglecting the chromatic dispersion,but taking the group-velocity mismatch,the initial time delay between two optical pulses with different carrier frequencies,and the quintic nonlinearity into account,the analytical expressions for the nonlinear phase shifts and frequency chirps of two Gaussian pulses were derived.The results show that,in comparison with the case of cubic nonlinearity,the coexistence of cubic and quintic nonlinearity can make the effects of the group-velocity mismatch and the initial time delay on the nonlinear phase shifts and frequency chirps more comprehensive and complicated.This investigation may contribute to the fields of the optical switching devices and frequency conversion,etc.