高非线性光纤正常色散区产生超连续谱的数值研究

基于广义非线性薛定谔方程,通过数值计算对高非线性光纤正常色散区产生超连续谱进行了研究.结果表明,抽运脉冲的峰值功率、脉冲宽度以及脉冲初始啁啾对该光纤正常色散区超连续谱的形成有极其重要的影响;在高非线性光纤正常色散区产生超连续谱的过程中,三、四阶群速度色散甚至更高阶群速度色散对超连续谱的影响完全可以忽略,但与其他高非线性效应相比,自陡峭效应对超连续谱产生的影响更为明显.高功率超短光脉冲在高非线性光纤正常色散区,得到了没有泵浦成份残余、－20 dB谱宽达400 nm以上而频谱强度起伏小于10 dB的超宽而平坦超连续谱.

Numerical Simulation of Supercontinuum Generation in High Nonlinear Fiber Pumped at the Normal Dispersion Region

Based on the generalized nonlinear Schrdinger equation desiring pulse propagation in fiber,the supercontinuum generation in high nonlinear fiber pumped at the normal dispersion region was investigated.The results show that the pulse width,peak power and initial chirp of the pump pulse are very important to flat wideband supercontinuum generation. The supercontinuum generated in high nonlinear fiber with the normal dispersion,the effect of the third,fourth order dispersion even the higher-order dispersion on supercontinuum spectrum can be ignored,the self-steepening was effect on supercontinuum spectrum generation than other higher-order nonlinear effects. A broadband and flat supercontinuum is 400 nm at-20 dB,the spectral intensity fluctuation is 10 dB and without residual pump generated from high nonlinear fiber pumped at the normal dispersion region.