基于脉冲在光纤中传输所满足的非线性薛定谔方程,采用数值计算的方法对脉冲在高非线性光纤中演化成自相似抛物线脉冲的传输特性进行了研究。结果表明, 脉冲在不同初始能量和啁啾参量的情况下,高非线性光纤产生自相似抛物线脉冲,且随着归一化长度的增大, 脉冲的自相似指数从0.0796减小到0.0720。进一步的研究表明: 啁啾高斯脉冲在光纤传输过程中,脉冲逐渐展宽,同时正啁啾越大,其自相似演化结果越差;参数N=8的正负啁啾脉冲分别演化成平顶自相似抛物线脉冲以及三角形脉冲。

Based on the generalized nonlinear Schrodinger equation desiring pulse propagation in fiber, the propagation properties of self-similar parabolic pulse in high nonlinear fiber are investigated by numerical methods. The results show that when the pulses have the different initial energy and chirp parameters, the pulse in the high nonlinear fiber can evolve into the self-similar parabolic pulse, and with the increase of the normalized length, the self-similar factor of the pulse decreases from 0.0796 to about 0.0720. It is further investigated that the chirped Gaussian pulse transmission in fiber is widen gradually. The effect of the negative chirp on the self-similar evolution is greater than that of the positive chirp. The high energy positive and negative chirp pulses are evolved into the flat-top parabolic pulse and triangular pulse.