利用分步傅里叶变换法对飞秒激光脉冲在纳米光纤中产生超连续谱的过程进行了数值模拟,分析了纳米光纤直径、输入脉冲的峰值功率以及脉冲宽度等对纳米光纤中超连续谱产生的影响。通过模拟分析发现:输入脉冲脉宽越窄,光谱展宽越为明显;输入脉冲峰值功率越高,超连续谱(SC)过程越明显;当输入脉冲一定时,纳米光纤的直径与超连续谱的产生有着至关重要的作用:超连续谱的产生与光纤半径并不成线性关系,当输入脉冲的中心波长与纳米光纤的直径相匹配时,超连续谱产生最为明显。以上结论对进一步研究和利用纳米光纤中的超连续谱有着非常重要的意义。
Using split-step Fourier transform method, the authors performed the simulation on supercontinuum generation (SCG) of femtosecond laser in nanofiber. The effects of diameter of the nanofiber, peak power and input pulse duration on the supercontinuum generation were analyzed. The results show that the higher the peak power of the input pulse, the easier the su- percontinuum generation could be observed; the narrower the input pulse, the wider the light spectrum width. The dimension of the nanofiber plays an very important role in supercontinuum generaion of femtosecond laser pulse, the supercontinuum genera- tion is not inversely proportional to the diameter of nanofiber, and there is a optimum diameter of nanofiber for the certain input laser pulse, so that the supercontinuum generation can be noteworthy. The obtained results in this paper would be helpful for further research on and making use of the supercontinuum generation in nanofiber.