Self-consistent extraction of photoabsorption time delays in attosecond streak camera  

作　　者：Yutong Gao Hongcheng Ni Andreas Becker Jian Wu 

机构地区：[1]State Key Laboratory of Precision Spectroscopy,East China Normal University,Shanghai 200241,China [2]Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China [3]JILA and Department of Physics,University of Colorado,Boulder 80309-0440,USA [4]Chongqing Key Laboratoryof PrecisionOptics,Chongqing Institute of East China Normal UniversityChongqing 4112,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2024年第12期8-16,共9页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.92150105,12227807,and 12241407);the Science and Technology Commission of Shanghai Municipality (Grant Nos.21ZR1420100,and 23JC1402000);support by a grant from the U.S.Department of Energy,Division of Chemical Sciences,Atomic,Molecular and Optical Sciences Program (Grant No.DESC0001771)。

摘　　要：Photoionization can generally be decomposed into a photoabsorption process plus a half-scattering process.The streaking time delay observed in the attosecond streak camera,correspondingly,can be decomposed into a photoabsorption time delay and a continuum time delay.We propose a self-consistent method to account for the potential-laser coupling effect and extract the intrinsic absorption time delay,without invoking an implicit assumption of a constant continuum correction made in previous streaking studies.The concept is based on an iterative technique starting from an initial guess of the absorption time delay and using classical electron trajectories to consistently remove the coupling-induced momentum shift to the streak signal.We show that the self-consistent iterative algorithm converges quickly and is robust against different initial guesses.The method is applied to laser-induced ionization of atoms to obtain the absorption time delay in resonant two-photon ionization and to explore possible time delays in above-threshold ionization.The results confirm an absorption time delay linearly dependent on the ionizing pulse duration in resonant two-photon ionization.The method is also shown to perform better than conventional methods and to identify a small negative absorption time delay(less than 2 attoseconds) in above-threshold ionization.

关 键 词：attosecond streak camera photoabsorption time delay PHOTOIONIZATION 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] TN24[自动化与计算机技术—计算机科学与技术]