光子晶体光纤中基于交叉相位调制的脉冲压缩

为了研究飞秒双脉冲在光子晶体光纤不同色散区的非线性传输过程,采用分步傅里叶方法求解耦合的非线性薜定谔方程组,并进行了理论分析。讨论了不同抽运功率、不同抽运脉冲啁啾参量以及不同脉宽比对信号脉冲压缩的影响。结果表明,基于交叉相位调制效应,弱信号脉冲不仅能够被压缩,而且光纤存在最佳压缩长度。增大抽运脉冲输入功率,选取正啁啾抽运脉冲,可以得到更大的信号脉冲压缩因子,同时最佳光纤长度减小。另外,不同的脉冲宽度对信号脉冲的压缩产生大的影响,较窄脉宽的抽运脉冲易于产生较短的压缩信号脉冲。这一结果对用光子晶体光纤压缩弱信号脉冲提供了理论参考。

Soliton-effect compression due to cross-phase modulation in photonic crystal fibers

Based on both the coupled nonlinear Schrödinger equations,the nonlinear propagation of two femtosecond laser pulses in the different regimes of photonic crystal fibers was solved by solving the equation group with the slip-step Fourier method.The effect of the pump pulse power,pump frequency chirp and various pulse widths on signal pulse compression was discussed in detail.The numerical results show that the signal pulse can be compressed through cross-phase modulation and the optimum fiber length can be obtained.It is also found that the compression factor increases with initial positive chirp and power, however,the optimum fiber length decreases.In order to obtain larger compression factor,pump pulses with narrow pulse-width are desirable selected.These results offer theoretical references for weak signal pulse compression by using photonic crystal fibers.