双波长圆偏振光场中分子电离动力学的研究新进展  

Research Advances in Ionization Dynamics of Molecules for Bi-Wavelength Circularly Polarized Laser Field

作　　者：郭振宁 刘运全[1,2,3] Guo Zhenning;Liu Yunquan(State Key Laboratory of Artificial Microstructure and Mesoscopic Physics,School of Physics,Peking University,Beijing 100871,China;Collaborative Innovation Center of Quantum Matter,Beijing 100871,China;Collaborative Innovation Center of Extreme Optics,Taiyuan 030006,Shanxi,China)

机构地区：[1]北京大学物理学院人工微结构与介观物理国家重点实验室,北京100871 [2]量子物质协同创新中心,北京100871 [3]极端光学协同创新中心,山西太原030006

出　　处：《光学学报》2024年第2期10-23,共14页Acta Optica Sinica

基　　金：国家自然科学基金(92050201,92250306);国家重点基础研究发展计划(2022YFA1604301)。

摘　　要：超短激光脉冲的出现为人们研究原子分子内电子的超快动力学过程提供了重要的技术手段。强激光诱导原子分子的光电离过程是光诱导物理过程的基石,也是目前强场物理领域的前沿热点之一。本文重点综述了双波长圆偏振光场中分子电离动力学的研究进展。首先,介绍了研究强场分子电离动力学的半经典模型,给出了电离电子波包的相位和振幅分布。然后,介绍了利用双波长圆偏振光场测量H2分子和CO分子的电离动力学的研究,发现电离电子的振幅结构以及隧穿后电子受到的长程库仑势都会影响电子的动力学过程。此外,电子波包的相位结构也会包含在光电子的发射角中,这个初始相位编码了电子吸收光子而电离过程中的时域信息。最后,对新型阿秒钟在分子光电离过程中的应用进行了总结,并展望了未来复杂分子体系的应用前景。Significance The measurement and control of ultrafast dynamics of electrons in atoms and molecules are always the goal of scientists.The electrons in molecules and atoms move with a timescale of attoseconds,so it is necessary to develop attosecond resolution technology to detect the motion of electrons accurately.Strong laser-induced ionization of atoms and molecules,as the footstone of laser-induced physical phenomena,is one of the frontiers of ultrafast topics.The attoclock technology,using circularly polarized femtosecond laser pulses,has become an important experimental tool for studying photoionization dynamics and has been widely used to study the tunneling time delay of atomic system.For molecular systems,due to the complexity of molecular orbitals,the study on molecules with attoclock is less explored and it is crucial to understand the ionization dynamical process of molecules.Progress The attoclock have pioneered the experimental study of photoionization time delays.By using a circularly polarized field to deflect ionized photoelectrons at different times to various angles in momentum space.Similar to the hands of a clock,a correlation is established between the ionization time and the final emission angle of electrons.Attoclock technology has been widely used to measure the tunneling time delay of atomic systems since it was proposed.Recently,the improved attoclock approach has been demonstrated,which was based on a two-color field(800 nm strong circularly polarized field for ionization,and 400 nm weak linear polarization field for marking the ionization instance)to investigate the tunneling time of atoms.Additionally,a double-hand attoclock is used to retrieve the phase structure of the photoelectron wave packet,which provide an important approach for studying the time delay of strong-field ionization of atoms.We will discuss the bi-circular attoclock configurations to study the ionization dynamics of H2 and CO molecules.Conclusions and Prospects In this paper,we summarized the recent study on ionizat

关 键 词：原子分子物理学 强场光物理 隧道电离 多光子电离 分子半经典模型 

分 类 号：O436[机械工程—光学工程]