三五阶非线性下光纤中脉冲对的啁啾和频谱  

Frequency chirps and spectra of pulse pairs in an optical fiber with cubic-quintic nonlinearity

作　　者：钟先琼[1] 向安平[1] 罗莉[1] 李旭[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：《红外与激光工程》2006年第z3期38-42,共5页Infrared and Laser Engineering

基　　金：四川省科技厅应用基础项目(05JY029-084);成都信息工程学院科技发展基金项目(KYTZ20060604)资助

摘　　要：为探究光纤的三五阶非线性对脉冲对频谱展宽的影响,从包含三五阶非线性的耦合非线性薛定谔方程出发,在忽略光纤色散和脉冲间走离效应的情况下,解析并计算模拟了高斯光脉冲对由于交叉相位调制所产生的非线性相移、频率啁啾,数值模拟了光脉冲对传输中的功率频谱。结果表明:与只有三阶非线性相比,正五阶非线性使非线性相移和频率啁啾增大,而负五阶非线性则使非线性相移和频率啁啾减小甚至反号;正五阶非线性使脉冲频谱变宽,谱峰数目增多;绝对值较小的负五阶非线性使频谱变窄,谱峰数目减小,谱形变化,绝对值较大的负五阶非线性则展宽频谱,并使脉冲中心附近的谱峰变强。五阶非线性对功率相对较小的脉冲的影响更大些。此研究对超连续谱的产生、光开关器件、光脉冲压缩等研究都有一定的意义。The purpose of the paper is to investigate the effects of the cubic-quintic nonlinearity of an optical fiber on the spectral broadening of pulse pairs.Neglecting the chromatic dispersion and the walk-off effect between the pulses,starting from the coupled nonlinear Schrdinger equations including cubic-quintic nonlinearity,the nonlinear phase shifts and frequency chirps of Gaussian optical pulse pairs caused by cross-phase modulation are analyzed and simulated.The power spectra of pulse pairs during propagation are numerically simulated.The results show that,in comparison with the case of only cubic nonlinearity,the positive quintic nonlinearity makes the nonlinear phase shifts and frequency chirps increase,while the negative one makes them decrease and even become the opposite signs.Moreover,the positive quintic nonlinearity broadens the spectra and makes the number of peaks increase.The negative quintic nonlinearity with smaller absolute value narrows the spectral width,decreases the number of spectral peaks,and changes the spectral shapes.While the negative quintic nonlinearity,with larger absolute value,broadens the spectra and intensifies the spectral peaks near the central range of the pulses.In addition, the quintic nonlinearity will affect the pulse whose power is lower more considerable.This investigation will contribute to generation of supercontinuum spectrum,optical switching devices,compressions of optical pulses,and study of the characteristics of nonlinear materials to some degrees.

关 键 词：非线性光学 三五阶非线性 交叉相位调制 频率啁啾 功率频谱 

分 类 号：O437[机械工程—光学工程] TN929.11[理学—光学]