激发态氢原子光电离中的偏振效应  

Polarization Effects in Photoionization of Excited Hydrogen Atom

作　　者：钟铭宸 万文钦 皮良文 姜维超 Zhong Mingchen;Wan Wenqin;Pi Liangwen;Jiang Weichao(Institute of Quantum Precision Measurement,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,Guangdong,China;Center for Attosecond Science and Technology,Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi’an 710119,Shaanxi,China)

机构地区：[1]深圳大学物理与光电工程学院量子精密测量研究所,广东深圳518060 [2]中国科学院西安光学精密机械研究所阿秒科学与技术研究中心,陕西西安710119

出　　处：《光学学报》2024年第16期11-19,共9页Acta Optica Sinica

基　　金：国家自然科学基金(12074265,92250303);广东省基础与应用基础研究基金(2022A1515010329);陕西省基础研究基金重点项目(E23326D1)。

摘　　要：通过数值求解三维含时薛定谔方程,从理论上研究了氢原子2pz激发态在不同偏振方向的线偏振激光脉冲作用下的光电子动量分布。本文研究发现,无论是处于隧穿电离区还是多光子电离区,当偏振方向与初态极化方向的夹角不为0或π/2时,光电子动量分布相对于激光脉冲偏振方向是不对称的,这种不对称性源于初始电子波函数相对于激光偏振方向的不对称分布。此外,本文还讨论了实验上观察这种不对称光电子分布的可行的泵浦-探测方案。Objective The interaction between strong laser fields and matter has emerged as a prominent tool for probing the internal structure of atoms and molecules and field-induced ultrafast electron dynamics.During the multiphoton ionization of atoms and molecules by intense laser pulses,ionized electron wave packets from different paths interfere,resulting in complex interference patterns in the photoelectron momentum distributions(PMDs).Over the past decades,a prominent interference structure known as strong-field photoelectron holography(SFPH)has been observed.In molecule fields,researchers use holographic structures to probe molecular structure and orientation dynamics information,but no relevant literature has been found in the atomic field.By numerically simulating the interaction between the excited state 2p_(z)of a hydrogen atom and linearly polarized laser pulses with different polarization directions,we can extract the structural information of atomic orbitals from the PMDs.In addition,we also discuss a feasible pump-probe scheme for experimental validation.Methods To simulate atomic ionization in a linearly polarized laser field,we numerically solve the three-dimensional time-dependent Schrödinger equation(TDSE)in the velocity gauge with dipole approximation.We use the finite-element discrete variable representation(FE-DVR)method to discretize the radial part of the wave function.For the time evolution of the wave function,we use the split-Lanczos method.After the laser pulse concludes,the ionization probability is extracted from the final wave function by projecting it onto the scattering state.Results and Discussions The configuration of the present laser-atom interaction is illustrated in Fig.1.The quantization axis of the state 2p_(z)is along the z-axis.Two polarization directions of the laser pulse,Θ=0[Fig.1(a)]andπ/6[Fig.1(b)],are presented.The wavelength,pulse duration,and peak intensity of the laser pulse are fixed to be 2000 nm,10 optical cycles,and 10^(13)W/cm^(2),respectively.The PMDs at differe

关 键 词：原子与分子物理 强场电离 激发态 偏振效应 

分 类 号：O562.4[理学—原子与分子物理]