Probing subcycle spectral structures and dynamics of high-order harmonic generation in crystals  

作　　者：Long Lin Tong-Gang Jia Zhi-Bin Wang Peng-Cheng Li 林龙;贾铜钢;王志斌;李鹏程(Research Center for Advanced Optics and Photoelectronics,Department of Physics,College of Science,Shantou University,Shantou 515063,China;Key Laboratory of Intelligent Manufacturing Technology of MOE,Shantou University,Shantou 515063,China;College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,China)

机构地区：[1]Research Center for Advanced Optics and Photoelectronics,Department of Physics,College of Science,Shantou University,Shantou 515063,China [2]Key Laboratory of Intelligent Manufacturing Technology of MOE,Shantou University,Shantou 515063,China [3]College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,China

出　　处：《Chinese Physics B》2022年第9期273-280,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.12074239 and 91850209);the Natural Science Foundation of Guangdong Province,China(Grant Nos.2020A1515010927 and 2020ST084);Department of Education of Guangdong Province,China(Grant Nos.2019KTSCX038 and 2020KCXTD012);Shantou University(Grant No.NTF18030);the Natural Science basic Research Program of Shaanxi Province,China(Grant No.2022JM-015);Scientific Research Foundation of SUST(Grant No.2017BJ-30).

摘　　要：Subcycle spectral structures and dynamics of high-order harmonic generation(HHG)processes of atoms and molecules driven by intense laser fields on the attosecond time scale have been originally studied theoretically and ex-perimentally.However,the time scale of HHG dynamics in crystals is in the order of sub-femtosecond,and the carrier dynamics of HHG in crystals driven by subcycle laser pulses are largely unexplored.Here we perform a theoretical study of subcycle structures,spectra,and dynamics of HHG of crystals in mid-infrared laser fields subject to excitation by a subcycle laser pulse with a time delay.The HHG spectra as a function of time delay between two laser fields are cal-culated by using a single-band model for the intra-band carrier dynamics in crystal momentum space and by solving the time-dependent Schr?dinger equation in velocity gauge for the treatment of multi-band crystal systems.The results exhibit a complex time-delay-dependent oscillatory pattern,and the enhancement and suppression of the HHG related to subcycle pulse are observed at the given time delay in either single-band or multi-band crystal systems.To understand oscillation structures with respect to the dependence for the subcycle laser fields,the time-frequency characteristics of the HHG as well as the probability density distribution of the radiation are analyzed in detail.

关 键 词：high-order harmonic generation carrier dynamics subcycle laser pulses crystal systems 

分 类 号：O73[理学—晶体学] O562