中国物理B ›› 2023, Vol. 32 ›› Issue (6): 63302-063302.doi: 10.1088/1674-1056/acc80a

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Generation of quasi-chirp-free isolated attosecond pulses from atoms under the action of orthogonal two-color combined pulse of fundamental frequency and higher intensity second harmonic fields

Rui-Xian Yu(蔚瑞贤)1,2, Yue Qiao(乔月)1,2, Ping Li(李萍)1,2, Jun Wang(王俊)1,2, Ji-Gen Chen(陈基根)3, Wei Feng(冯伟)1,2,†, Fu-Ming Guo(郭福明)1,2,‡, and Yu-Jun Yang(杨玉军)1,2,§   

  1. 1 Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China;
    2 Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy(Jilin University), Changchun 130012, China;
    3 Zhejiang Provincial Key Laboratory for Cutting Tools, Taizhou University, Jiaojiang 31800, China
  • 收稿日期:2023-02-20 修回日期:2023-03-17 接受日期:2023-03-28 出版日期:2023-05-17 发布日期:2023-06-12
  • 通讯作者: Wei Feng, Fu-Ming Guo, Yu-Jun Yang E-mail:fengw@jlu.edu.cn;guofm@jlu.edu.cn;yangyj@jlu.edu.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant No. 2019YFA0307700), the National Natural Science Foundation of China (Grant Nos. 12074145, 11627807, and 11975012), the Research Foundation for Basic Research of Jilin Province, China (Grant No. 20220101003JC), the Fundamental Research Funds for the Central Universities of China (Grant No. 30916011207), and the Outstanding Youth Project of Taizhou University (Grant No. 2019JQ002). We acknowledge the High Performance Computing Center of Jilin University for supercomputer time.

Generation of quasi-chirp-free isolated attosecond pulses from atoms under the action of orthogonal two-color combined pulse of fundamental frequency and higher intensity second harmonic fields

Rui-Xian Yu(蔚瑞贤)1,2, Yue Qiao(乔月)1,2, Ping Li(李萍)1,2, Jun Wang(王俊)1,2, Ji-Gen Chen(陈基根)3, Wei Feng(冯伟)1,2,†, Fu-Ming Guo(郭福明)1,2,‡, and Yu-Jun Yang(杨玉军)1,2,§   

  1. 1 Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China;
    2 Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy(Jilin University), Changchun 130012, China;
    3 Zhejiang Provincial Key Laboratory for Cutting Tools, Taizhou University, Jiaojiang 31800, China
  • Received:2023-02-20 Revised:2023-03-17 Accepted:2023-03-28 Online:2023-05-17 Published:2023-06-12
  • Contact: Wei Feng, Fu-Ming Guo, Yu-Jun Yang E-mail:fengw@jlu.edu.cn;guofm@jlu.edu.cn;yangyj@jlu.edu.cn
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant No. 2019YFA0307700), the National Natural Science Foundation of China (Grant Nos. 12074145, 11627807, and 11975012), the Research Foundation for Basic Research of Jilin Province, China (Grant No. 20220101003JC), the Fundamental Research Funds for the Central Universities of China (Grant No. 30916011207), and the Outstanding Youth Project of Taizhou University (Grant No. 2019JQ002). We acknowledge the High Performance Computing Center of Jilin University for supercomputer time.

摘要: The intrinsic chirp of high-order harmonic generation is an important factor limiting the production of ultrashort attosecond pulses. Based on numerically solving the time-dependent Schrödinger equation, the generation process of high-order harmonic from the He atom under the action of orthogonal two-color combined pulse of fundamental frequency and higher intensity second harmonic fields is studied. In this paper, we propose to achieve quasi-chirp-free isolated attosecond pulses by superimposing a higher second-harmonic field on the orthogonal direction of the fundamental frequency field. It is found that the high-energy part of its harmonic emission exhibits small chirp characteristics, which can be used to synthesize isolated attosecond pulses. Through the analysis of the wave packets evolution and the classical motion trajectories of the electron, it is demonstrated that the quasi-chirp-free harmonic can be attributed to the simultaneous return of electrons ionized at different times to the parent particle. The influence of the relative phase of the two pulses on the harmonics is further analyzed, and it is observed that this phenomenon is sensitive to the relative phase, but it can still generate isolated attosecond pulses within a certain phase.

关键词: high-order harmonic, orthogonal two-color fields, relative phase, quasi-chirp-free isolated attosecond pulses

Abstract: The intrinsic chirp of high-order harmonic generation is an important factor limiting the production of ultrashort attosecond pulses. Based on numerically solving the time-dependent Schrödinger equation, the generation process of high-order harmonic from the He atom under the action of orthogonal two-color combined pulse of fundamental frequency and higher intensity second harmonic fields is studied. In this paper, we propose to achieve quasi-chirp-free isolated attosecond pulses by superimposing a higher second-harmonic field on the orthogonal direction of the fundamental frequency field. It is found that the high-energy part of its harmonic emission exhibits small chirp characteristics, which can be used to synthesize isolated attosecond pulses. Through the analysis of the wave packets evolution and the classical motion trajectories of the electron, it is demonstrated that the quasi-chirp-free harmonic can be attributed to the simultaneous return of electrons ionized at different times to the parent particle. The influence of the relative phase of the two pulses on the harmonics is further analyzed, and it is observed that this phenomenon is sensitive to the relative phase, but it can still generate isolated attosecond pulses within a certain phase.

Key words: high-order harmonic, orthogonal two-color fields, relative phase, quasi-chirp-free isolated attosecond pulses

中图分类号:  (Spectra induced by strong-field or attosecond laser irradiation)

  • 33.20.Xx
42.65.Ky (Frequency conversion; harmonic generation, including higher-order harmonic generation)