预啁啾和脉冲沿锐度对光脉冲线性传输的影响  

Effects of initial chirps and sharpness of pulse edge on linear propagation of optical pulses

作　　者：陈旭[1] 钟先琼[1] 

机构地区：[1]成都信息工程学院光电技术系,四川成都610225

出　　处：《成都信息工程学院学报》2007年第z1期129-132,共4页Journal of Chengdu University of Information Technology

摘　　要：从忽略光纤非线性效应的光脉冲非线性薛定谔方程出发,在光纤正色散区,利用傅立叶变换和反傅立叶变换模拟了不同初始啁啾的二阶与四阶超高斯光脉冲波形随距离的三维演化。分析讨论了脉冲沿锐度以及脉冲预啁啾对脉冲波形演化的综合影响。结果表明:不论脉冲有无预啁啾,光脉冲波形最终都将随着传输距离的增大而展宽。但是负预啁啾将使脉冲波形在脉冲传输的初始阶段发生严重的畸变,即脉冲会分裂成尖峰结构,并且尖峰的数目和能量分布随距离而变。而当预啁啾为正或零时,脉冲前期的畸变很弱。随着脉冲沿锐度的增大,脉冲畸变会加强。此外,在脉冲的前后边缘会出现矮小的峰。整个脉冲波形都是中心对称的。Neglecting the nonlinear effect of optical fiber and starting from the nonlinear Schr dinger equation of the optical pulse,the three dimensional shape evolutions of the second and fourth-order chirped super-Gaussian optical pulses with the propagation distance in the positive dispersion region of the optical fiber are simulated by using Fourier transformation and anti-Fourier transformation method.The synthetic effects of the sharpness of pulse edge and the initial frequency chirps on the shape evolutions of the optical pulses are analyzed and discussed.The result shows that whether the pulses are initially chirped or not,their shapes all broaden with the increase of the propagation distance.However,in the case of negative initial chirps the pulse shapes may distort seriously at the early propagation stage.Concretely,the pulses may split into some sharp peak structures.Furthermore,the number of shape peaks and the energy distributing among them vary with the distance.When the initial chirps are positive or zero the early pulse distortion of the pulses is very weak.The pulse distortion is intensified with the increase of the sharpness of pulse edge.In addition the short weak peaks may occur on the leading and training edges of optical pulses.Moreover,the pulse shapes are center symmetric.

关 键 词：预啁啾 色散 超高斯光脉冲 线性传输 

分 类 号：O437[机械工程—光学工程]