光纤中皮秒超高斯脉冲的传输特性研究

A study on the propagation properties of picoseconds super-gaussian pulse in optical fibers

用龙格—库塔算法对描述超高斯脉冲在光纤中传输的微分方程组进行了数值求解,数值结果表明光纤的二阶色散、三阶色散和脉冲初始啁啾使脉宽展宽,光纤非线性对脉宽有压缩作用。求出了能使超高斯脉冲在光纤中持续保形传输的用非线性系数归一化的二阶色散系数,该系数随超高斯脉冲的锐度因子增大而减小。当脉冲不能保形传输时频率与相位出现抖动,由此带来更严重的频率啁啾,而光纤三阶色散和初始啁啾的增大也会加剧频率与相位的抖动。

By using Runge-kutta algorithm,calculates the differential equations that describe the evolution of picoseconds super-gaussian pulse in optical fibers.The numerical result indicates that the second-order dispersion,the third-order dispersion and the initial chirp of the pulse broaden the pulse,and the fiber nonlinear-effects compress the width.Obtained the coefficient of the secondorder dispersion（normalized by nonlinear coefficient）that can guarantee the conformal transmission of the pulse.The coefficient gets smaller with the increasing of the factor of the sharpness of super-gaussian pulse,shift of frequency and phase and more serious chirp of frequency appeared when pulse can not transmit conformally,the shift of frequency and phase intensified with the increase of the third-order dispersion and the initial chirp.