脉冲沿不同方向入射时的脉冲俘获现象研究

A research of the pulse trapping characteristics along the direction of incidence

数值模拟分析了泵浦脉冲和信号脉冲分别沿快轴和慢轴入射到一种高双折射光子晶体光纤时,泵浦脉冲入射条件对脉冲俘获效应的影响.结果表明:选择合适的时域中心延迟可以得到最佳的脉冲俘获效果;增加泵浦脉冲的峰值功率,泵浦脉冲红移量和信号脉冲蓝移量增加,但功率增加到一定程度,信号脉冲输出频谱很窄,不容易实现脉冲俘获;增加泵浦脉冲半宽度,信号脉冲输出频谱强度越来越小,俘获效果变差;泵浦脉冲中心波长的选择直接影响信号脉冲和泵浦脉冲的群速度差,如果波长的改变导致群速度差变大,则脉冲俘获效果变差,甚至消失.

A theoretical investigation of the pulse trapping has been analyzed and different incidence conditions have been discussed when the two pulses are polarized along the fast axis and slow axis, respectively.The numerical simulation results show that the optimal pulse trapping effect can be obtained by choosing the appropriate time domain center delay.The red shift of the pump pulse and the blue shift of the signal pulse are larger when the peak power of the pump pulse increases.But it is difficult to achieve pulse trapping when the power increases to a certain extent.With the increase of pump pulse half-width,the signal pulse output spectrum intensity be- comes smaller and the pulse trapping becomes worse.If the change of wavelength leads to a large group velocity difference, the pulse trapping effect decreases, or even disappears.