脉冲啁啾对于阿秒脉冲的影响

采用单电子近似和软核势模型，通过数值求解一维含时薛定谔方程，理论研究了当脉冲分别带有正、负啁啾的情况下所产生的阿秒脉冲，分析了不同脉冲啁啾特性对阿秒脉冲的强度和宽度的影响，研究结果表明，无论是正啁啾还是负啁啾，随着啁啾量的增加，都将使激光脉冲由产生单个阿秒脉冲趋向于产生阿秒脉冲链，正啁啾和负啁啾对于阿秒脉冲宽度的影响是不同的，负啁啾对于阿秒脉冲宽度影响很小，适当的负啁啾有利于缩小阿秒脉冲的宽度；而正啁啾脉冲产生的阿秒脉冲较无啁啾时展宽，且随着啁啾量的增加，其阿秒脉冲宽度迅速增大。

With soft-core potential model and single electron approximation, the dependence of attosecond pulses on the chirp of the excitation pulse is theoretically investigated by solving 1D time-dependent Schr’dinger equation. The intensity and duration of the attosecond pulses are respectively analyzed. The results show that, instead of producing single attosecond pulse as the unchirped pulse, both the positively and negatively chirped laser pulses will produce attosecond pulse trains. With the increase of the positive chirp of the driving laser pulse , the duration of the attosecond pulse will increase greatly, while the negatively chirped pulse′s effect is little, and some negative chirp can even generate shorter attosecond pulse than that of the zero chirp case.