双色反旋圆偏振激光场中分子的非序列双电离  

Nonsequential Double Ionization of Molecules in Counter-Rotating TwoColor Circularly Polarized Laser Fields

作　　者：郭祯 白丽华[1] 刘可盈 申雁雯 Guo Zhen;Bai Lihua;Liu Keying;Shen Yanwen(Department of Physics,College of Sciences,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学理学院物理系,上海200444

出　　处：《光学学报》2022年第21期98-105,共8页Acta Optica Sinica

基　　金：上海市自然科学基金(18ZR1413600)。

摘　　要：利用经典系综方法,研究了氮气(N_(2))分子在周期量级双色反旋圆偏振激光场中的非序列双电离(NSDI),发现在确定的激光强度下,随着激光波长的增加,NSDI的产量明显减小,这是因为电子波包的扩散作用。研究发现NSDI电离机制受到激光波长的影响,随着激光波长的增大,碰撞激发电离越来越占主导,这与第一个电子的返回轨迹和返回能量有关。讨论了NSDI的电子动量分布,电子动量分布随激光波长有明显变化,激光波长越长,“旋转三瓣扇形”结构越明显。Nonsequential double ionization(NSDI)of N_(2) molecules in counterrotating twocolor circularly polarized fewcycle laser fields is investigated by the classical ensemble method.The results show that for the determined laser intensity,the yield of NSDI decreases significantly with the increasing laser wavelength,which is caused by the diffusion effects of electron wave packets.It is also found that the ionization mechanism of NSDI is affected by the laser wavelength.Collision excitation ionization becomes increasingly dominant with the rising laser wavelength,which is related to the return trajectory and return energy of the first electron.At the same time,the electron momentum distribution of NSDI is discussed in this paper.The electron momentum distribution varies significantly with the laser wavelength,and the longer laser wavelength leads to clearer"rotating threelobed fanlike"structures.

关 键 词：原子与分子物理学 非序列双电离 双色反旋圆偏振激光场 碰撞激发电离 经典系综方法 动量分布 

分 类 号：O562.4[理学—原子与分子物理] O562.5[理学—物理]