强激光场驱动Ar原子电离中的隧穿延时  

Tunneling delay time in strong field ionization of atomic Ar

作　　者：赵猛 全威 肖智磊 许松坡 王志强 王明辉 成思进 吴文卓 王艳兰 赖炫扬 柳晓军 Zhao Meng;Quan Wei;Xiao Zhi-Lei;Xu Song-Po;Wang Zhi-Qiang;Wang Ming-Hui;Cheng Si-Jin;Wu Wen-Zhuo;Wang Yan-Lan;Lai Xuan-Yang;Liu Xiao-Jun(State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430071,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Department of Physics,Hubei University,Wuhan 430062,China)

机构地区：[1]中国科学院精密测量科学与技术创新研究院,波谱与原子分子物理国家重点实验室,武汉430071 [2]中国科学院大学物理科学学院,北京100049 [3]湖北大学物理系,武汉430062

出　　处：《物理学报》2022年第23期86-95,共10页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2019YFA0307702);国家自然科学基金(批准号:11834015,11974383,12104465);湖北省自然科学基金重点类项目(批准号:2020CFA029)资助的课题.

摘　　要：阿秒钟实验方案是当前研究原子分子体系的价电子在强激光场中隧穿延时问题的有效手段.基于阿秒钟方案,本文实验研究了Ar原子在800 nm椭圆偏振激光场中的光电子动量分布随激光光强的演化规律.理论上采用包含库仑场效应、非绝热效应、Stark效应、多电子屏蔽和极化效应的半经典模型对Ar原子的强场电离动力学进行了模拟.通过对比实验测量和数值模拟结果发现,在本文所研究的光强范围内,Ar原子的价电子在800 nm椭圆偏振激光场中隧穿延时上限为10 as.进一步分析表明,阿秒钟方案中,考虑多电子屏蔽效应对得到的隧穿延时影响最小,而考虑非绝热效应的影响最大.“Attoclock”provides a promising experimental scheme to explore the timing of tunnel ionization of atoms and molecules in intense laser fields.In this work,we perform a systematical investigation of tunneling delay time in strong field ionization of atomic Ar,based on the“attoclock”experimental scheme.Experimentally,the laser intensity dependence of the photoelectron momentum distributions of Ar subject to strong elliptically polarized laser fields at 800 nm has been measured.Theoretically,a dedicated semiclassical model,in which the Coulomb potential effect,the nonadiabatic effect,the Stark effect,the multielectron screening and polarization effect have been well considered,is employed to simulate the ionization dynamics of Ar.By comparing the experimental and simulated results,an upper limit of 10 attoseconds for the tunneling delay time of Ar has been derived for the laser intensity ranges explored in this work.In addition,the influence of various physical effects on the extracted tunneling delay time,in the context of semiclassical model,has been analyzed.It is demonstrated that,under otherwise identical conditions,consideration of multielectron screening effect will give rise to the least change of the extracted tunneling delay time.In contrast,consideration of nonadiabatic effect will lead to the most significant change of the extracted tunneling delay time.

关 键 词：阿秒钟 隧穿延时 超快电离 

分 类 号：O56[理学—原子与分子物理] TN24[理学—物理]