【摘要】 根据含五阶非线性微扰修正项的非线性薛定谔方程,采用变分法,导出了光纤中类明孤子各参数随传输距离演化的方程组,研究了脉宽与距离、啁啾与脉宽之间的关系,并对描述相位和频率的方程组用龙格-库塔算法进行了数值求解。结果表明:五阶非线性使类明孤子的脉宽压缩,可在一定程度上抵消初始啁啾和三阶色散对脉宽的展宽作用;五阶非线性对类明孤子的相位和频率演化特性的影响不明显,因而适度的五阶非线性(γ在0.0001到0.1之间)有利于类明孤子的稳定传输。更多还原

【Abstract】 Based on MNLS,by using the method of variational principle,the influence of fifth-order nonlinearity on the propagation of soliton-like pulses in fiber is investigated,the evolution equations for the parameters are deduced,the relations between width and distance, chirp and width,are calculated and the evolution equations for frequency and phase are studied by using Runge-Kutta algorithm.The result indicates that five-order nonlinearity compresses the width and has little influence on frequency and phase,so appropriate nonlinearity(γ= 0.0001～0.01)is helpful to steady transmission of soliton-like pulses in fiber.更多还原