高阶色散对高斯脉冲在超常介质中传输的影响及色散的补偿

摘要

文中对超常介质和一些常规介质中色散系数进行了对比研究,发现超常介质中的各阶色散系数大于常规介质的色散系数大约3个数量级,也即在信号的传输过程中不再能忽略高阶色散的影响.基于非线性薛定谔方程,研究了高斯脉冲在超常介质中传输及各阶色散对脉冲形状的影响.发现在常规超常介质中三阶色散所致脉冲分裂是一个非常严重的问题.通过调整超常介质的结构参数,找到了既可使二阶色散得以补偿、又可使得高斯脉冲传输120 km而不出现分裂的真正可用于通信的情形.%This paper compares the dispersion in metamaterial and in some conventional media.It is found that each order of the dispersion in metamaterial is larger in three orders of magnitude than that in conventional media,so that high-order dispersions have to be taken into consideration in the signal propagation.We analyze the impact of each order of the dispersion on the propagation of Gaussian light pulse based on the nonlinear Schr(o)dinger equation and the beam propagation method (BPM).We find that third-order dispersion leads to a serious pulse splitting.A case is found in which Gaussian pulse can propagate in metamaterial to 120km without splits and second dispersion can be compensated by adjusting structure of metamaterial.This is significant to optical communications.