Tang Qingbin, Zhou Yueming, Huang Cheng, Liao Qing, Lu Peixiang
Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China.
Opt Express. 2012 Aug 13;20(17):19580-8. doi: 10.1364/OE.20.019580.
The electron dynamics in strong field nonsequential double ionization (NSDI) of nitrogen molecules by mid-infrared (MIR) laser pulses is investigated with the three-dimensional classical ensemble model. The numerical results show that in the MIR regime, the correlated behavior of the two electrons from NSDI is independent on the molecular alignment, contrary to the case in the near-infrared (NIR) regime where the electron correlations exhibit a strong alignment dependence. In consistent with the experimental results, our numerical results show that the longitudinal momentum spectrum of the doubly charged ion evolves from a wide single-hump structure at NIR regime into a double-hump structure when wavelength enters the MIR regime. This double-hump structure becomes more pronounced as the wavelength further increases. The responsible microscopic electron dynamics of NSDI at the MIR regime is explored by back analysis of the classical trajectories.
利用三维经典系综模型研究了中红外（MIR）激光脉冲对氮分子进行强场非顺序双电离（NSDI）过程中的电子动力学。数值结果表明，在中红外区域，非顺序双电离产生的两个电子的关联行为与分子取向无关，这与近红外（NIR）区域的情况相反，在近红外区域电子关联表现出强烈的取向依赖性。与实验结果一致，我们的数值结果表明，当波长进入中红外区域时，双电荷离子的纵向动量谱从近红外区域的宽单峰结构演变为双峰结构。随着波长进一步增加，这种双峰结构变得更加明显。通过对经典轨迹的反向分析，探索了中红外区域非顺序双电离中起作用的微观电子动力学。
