初始啁啾对高斯脉冲形成光孤子的影响

Influence of Initial Chirp on Soliton Form

本文通过解薛定谔方程分别研究了线性光纤中色散导致具有初始频率啁啾的高斯脉冲展宽的详细物理过程和非线性光纤中自相位调制导致光脉冲频谱展宽的详细物理过程 ,得到高斯脉冲在光纤中群速度色散所导致的频率啁啾在反常色散区是下啁啾 (负啁啾 ) ,与脉宽的关系是线性的 ,自相位调制所产生的频率啁啾是上啁啾 (正啁啾 ) ,在脉冲的中心部分近似为线性 ,当CPβ2 <0时 ,脉冲有一个初始窄化的阶段等结论。最后用计算机模拟光孤子传输估算出形成孤子的初始啁啾范围值。

In this paper,the detailed physical process of the GVD induced spectral broading in linear fiber and the SPM induced spectral broading in nonlinear fiber of Gause pulse with initial chirp are studied by solving the Nonlinear Schrodinger equation of optical soliton.Several conclusions are drawed:The frequency chirping of Gause pulse in the a normal dispersion region induced by GVD is negative chirp and is linear with pulse width;That induced by SPM is positive chirpand is linear in the middle part of the pulse;the pulse has an initial narrowing process when C_Pβ_2<0.The initial chirp values to form soliton are calculated from the optical soliton transmission figutes through computer simulation.