中国物理B ›› 2025, Vol. 34 ›› Issue (6): 63302-063302.doi: 10.1088/1674-1056/adc40c

所属专题： SPECIAL TOPIC — Ultrafast physics in atomic, molecular and optical systems

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Tuning the laser-dressed attosecond transient absorption spectra of a singly excited helium state using a shaped attosecond pulse with a spectral minimum

Yong Fu(傅勇)1, Feier Xu(徐霏儿)1, and Cheng Jin(金成)1,2,†   

  1. 1 Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China;
    2 MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Engineering Research Center of Semiconductor Device Optoelectronic Hybrid Integration in Jiangsu Province, Nanjing University of Science and Technology, Nanjing 210094, China
  • 收稿日期:2025-02-25 修回日期:2025-03-20 接受日期:2025-03-24 出版日期:2025-05-16 发布日期:2025-05-16
  • 通讯作者: Cheng Jin E-mail:cjin@njust.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 12274230) and the Funding of Nanjing University of Science and Technology (Grant No. TSXK2022D005).

Tuning the laser-dressed attosecond transient absorption spectra of a singly excited helium state using a shaped attosecond pulse with a spectral minimum

Yong Fu(傅勇)1, Feier Xu(徐霏儿)1, and Cheng Jin(金成)1,2,†   

  1. 1 Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China;
    2 MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Engineering Research Center of Semiconductor Device Optoelectronic Hybrid Integration in Jiangsu Province, Nanjing University of Science and Technology, Nanjing 210094, China
  • Received:2025-02-25 Revised:2025-03-20 Accepted:2025-03-24 Online:2025-05-16 Published:2025-05-16
  • Contact: Cheng Jin E-mail:cjin@njust.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 12274230) and the Funding of Nanjing University of Science and Technology (Grant No. TSXK2022D005).

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摘要： The attosecond extreme ultraviolet (XUV) pulse pump and femtosecond infrared (IR) pulse probe scheme is commonly used to study the dynamics and attosecond transient absorption (ATA) spectra of microscopic systems. In a recent report [Proc. Natl. Acad. Sci. USA 121 e2307836121 (2024 )], we showed that shaped XUV pulses with spectral minima can significantly alter the absorption line shape of helium's 2s2p doubly excited state within a few tens of attoseconds. However, it remains unclear if similar effects could be observed in a singly excited state. In this study, we use shaped XUV pulses to excite helium's 2p singly excited state and couple the 2p and 3d states with a delayed IR pulse. Comparing these results with those from Gaussian XUV pulses, we find that the ATA spectra for the shaped XUV pulses exhibit more pronounced changes with delay, while the changes for the Gaussian pulses are gradual. We also explain these differences through population changes and analytical models. Our findings show that shaped XUV pulses can regulate the dynamics and absorption spectra of a singly excited state

关键词: attosecond transient absorption, electron dynamics, spectral minima, line shape

Abstract: The attosecond extreme ultraviolet (XUV) pulse pump and femtosecond infrared (IR) pulse probe scheme is commonly used to study the dynamics and attosecond transient absorption (ATA) spectra of microscopic systems. In a recent report [Proc. Natl. Acad. Sci. USA 121 e2307836121 (2024 )], we showed that shaped XUV pulses with spectral minima can significantly alter the absorption line shape of helium's 2s2p doubly excited state within a few tens of attoseconds. However, it remains unclear if similar effects could be observed in a singly excited state. In this study, we use shaped XUV pulses to excite helium's 2p singly excited state and couple the 2p and 3d states with a delayed IR pulse. Comparing these results with those from Gaussian XUV pulses, we find that the ATA spectra for the shaped XUV pulses exhibit more pronounced changes with delay, while the changes for the Gaussian pulses are gradual. We also explain these differences through population changes and analytical models. Our findings show that shaped XUV pulses can regulate the dynamics and absorption spectra of a singly excited state

Key words: attosecond transient absorption, electron dynamics, spectral minima, line shape

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

  • 33.20.Xx
78.47.jb (Transient absorption) 42.65.Re (Ultrafast processes; optical pulse generation and pulse compression) 34.80.Dp (Atomic excitation and ionization)