Based on the generalized nonlinear Schrodinger equation, we present a numerical investigation of dispersive wave generation in photonic crystal fibers pumped with femtosecond pulses in the anomalous dispersion region. Both positive dispersion slope and negative dispersion slope for pump wavelength are studied. It is demonstrated that the wavelength of the dispersive wave can be blue-shifted or red-shifted relative to the center wavelength of the soliton, depending on the dispersion slope of the pump wavelength. The spectral–temporal dynamics of dispersive wave generation is shown using the cross-correlation frequency-resolved optical gating (X-FROG) technique, which is numerically computed with a windowed Fourier transform. Further, we find a phenomenon that the X-FROG spectrogram of the corresponding output signal exhibits a parabolic shape, which is consistent with the wavelength dependence of the group delay. In particular, the phenomenon of soliton trapping of the dispersive wave is observed with an i...

中文翻译：

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不同色散斜率光子晶体光纤中色散波产生的时空分析

基于广义非线性薛定谔方程，我们提出了在反常色散区域用飞秒脉冲泵浦的光子晶体光纤中色散波生成的数值研究。研究了泵浦波长的正色散斜率和负色散斜率。结果表明，根据泵浦波长的色散斜率，色散波的波长可以相对于孤子的中心波长发生蓝移或红移。使用互相关频率分辨光选通 (X-FROG) 技术显示色散波生成的光谱 - 时间动态，该技术使用加窗傅立叶变换进行数值计算。此外，我们发现相应输出信号的 X-FROG 频谱图呈现抛物线形状的现象，这与群延迟的波长相关性一致。特别是，用 i 观察到色散波的孤子俘获现象。