线偏振激光场驱动的原子受挫双电离的波长和强度依赖  

Wavelength and Intensity Dependence of Linear Polarization Laser Atom Frustrated Double Ionization

作　　者：陈红梅 李盈傧[1] 许景焜 秦玲玲 李怡涵 何锦锦 史璐珂 翟春洋 汤清彬[1] 余本海[1] CHEN Hongmei;LI Yingbin;XU Jingkun;QIN Lingling;LI Yihan;HE Jinjin;SHI Luke;ZHAI Chunyang;TANG Qingbin;YU Benhai(College of Physics and Electronic Engineering,Xinyang Normal University,Xinyang 464000,China)

机构地区：[1]信阳师范学院物理电子工程学院,河南信阳464000

出　　处：《信阳师范学院学报（自然科学版）》2022年第3期374-380,共7页Journal of Xinyang Normal University(Natural Science Edition)

基　　金：国家自然科学基金项目(12074329,12004323,12104389);河南省高等学校重点科研项目(20A140025);信阳师范学院“南湖学者奖励计划”青年项目;信阳师范学院青年科研基金项目(2021-QN-041)。

摘　　要：利用三维经典系综模型,研究了线偏振激光场驱动的原子受挫双电离(FDI)对波长和强度的依赖。研究表明,FDI更青睐于较短的波长且较低的强度。FDI的电离电子沿激光偏振方向的动量谱呈现明显的双峰结构,这与最近的实验结果一致。反演分析所有的FDI轨迹显示,FDI事件由碰撞激发场致电离机制主导,这与非次序双电离低强度的情况一致。此外,FDI中被俘获的电子主要有两种通道贡献:一种通道是,被俘获的电子再碰撞后立即电离,但最终被库仑场俘获;另一种通道是,被俘获的电子再碰撞后首先进入激发态,然后在激光场的峰值电离,最后被库仑场俘获。对于这两种通道,被俘获电子在电离出口的纵向速度和对应的矢势均不同。进一步的研究表明,更长的波长和更高强度的激光脉冲下,被俘获的电子可以被发射到更高的里德堡态。The dependence of wavelength and intensity onatom frustrated double ionization(FDI)driven by linearly polarized laser field is studied using a three-dimensional classical ensemble model.The numerical results show that FDI prefers shorter wavelength and lower intensity.Moreover,the electron momentum distribution along the laser polarization direction from FDI shows a significant bimodal structure,which is well consistent with the recent experiment results.Inversion analysis of all FDI trajectories shows that FDI events are dominated by the ionization mechanism of the collision excitation field,which is consistent with low intensity of non-sequential double ionization.In addition,two pathways are significantly contributed to FDI.In one,the captured electron is immediately ionized after recollision,but is eventually captured by the Coulomb field.In other way,the captured electron first enters an excited state after recollision,then ionizes at the peak of the laser field,and finally is captured by the Coulomb field.For these two channeis,the longitudinal velocity and the corresponding vector potential of the captured electron are different at the ionization exit.Further studies demonstrate that the captured electron can be emitted to higher rydberg states at longer wavelengths and higher intensities of laser pulses.

关 键 词：强激光场 受挫双电离 电子动力学 再碰撞过程 

分 类 号：O437[机械工程—光学工程]