色散条件下各向同性光纤中拉曼增益对光脉冲自陡峭的影响

摘要

Under the condition that the light pulses meet the slowly varying function pulses, the higher-order nonlinear Schrödinger equation has been deduced by taking into consideration the Raman gain. The linear operator and nonlinear operator specific expressions are obtained using split-step Fourier numerical method. The Raman gain on the self-steepening of the Gaussian pulse has been simulated and then the result is compared with the self-steepening effect without taking into consideration the Raman gain when the pulse propagate in the isotropic optical fiber. Raman gain specific impact on the self-steepening of the Gaussian pulse has been obtained under different conditions. Results show that the Raman gain may affect the Gaussian pulse broadening, pulse peak attenuation as well as the oscillation of the edge. These influences depend on the parameters of self-steepening, input power, and dispersion coefficient.%基于光脉冲所满足的慢变函数，详细推导了包含拉曼增益的高阶非线性薛定谔方程，在考虑色散的条件下，运用分步傅里叶方法对其数值分析，进而模拟仿真了拉曼增益对高斯脉冲在各向同性光纤中传播时自陡峭效应的影响，并与不考虑拉曼增益的自陡峭效应作比较，从而得出拉曼增益在不同条件下对高斯脉冲自陡峭效应的具体影响方式。结果表明，拉曼增益会影响高斯脉冲的展宽、脉冲峰值衰减以及在前后沿的振荡，其影响程度与具体的自陡峭参数、脉冲功率和色散系数的大小有关。