中国物理B ›› 2009, Vol. 18 ›› Issue (2): 624-629.doi: 10.1088/1674-1056/18/2/039
钟先琼, 向安平
Zhong Xian-Qiong(钟先琼)† and Xiang An-Ping(向安平)
摘要: Starting from the extended nonlinear Schr?dinger equation in which the self-steepening effect is included, the evolution and the splitting processes of continuous optical wave whose amplitude is perturbed into time related ultra-short optical pulse trains in an optical fibre are numerically simulated by adopting the split-step Fourier algorithm. The results show that the self-steepening effect can cause the characteristic of the pulse trains to vary with time, which is different from the self-steepening-free case where the generated pulse trains consist of single pulses which are identical in width, intensity, and interval, namely when pulses move a certain distance, they turn into the pulse trains within a certain time range. Moreover, each single pulse may split into several sub-pulses. And as time goes on, the number of the sub-pulses will decrease gradually and the pulse width and the pulse intensity will change too. With the increase of the self-steepening parameter, the distance needed to generate time-dependent pulse trains will shorten. In addition, for a large self-steepening parameter and at the distance where more sub-pulses appear, the corresponding frequency spectra of pulse trains are also wider.
中图分类号: (Ultrafast processes; optical pulse generation and pulse compression)