中国物理B ›› 2025, Vol. 34 ›› Issue (9): 93101-093101.doi: 10.1088/1674-1056/ade065

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

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Lasing and fluorescence of air plasma in presence of an external electric field

Kai-Lu Wang(王凯璐), Hai-Cheng Mei(梅海城), Liang Xu(许亮), and Yi Liu(刘一)†   

  1. Shanghai Key Laboratory of Modern Optical System, University of Shanghai for Science and Technology, Shanghai 200093, China
  • 收稿日期:2025-02-28 修回日期:2025-05-22 接受日期:2025-06-04 出版日期:2025-08-21 发布日期:2025-08-28
  • 通讯作者: Yi Liu E-mail:yi.liu@usst.edu.cn
  • 基金资助:
    Project supported by the Natural National Science Foundation of China (Grant Nos. 12034013 and 12204308) and Science and Technology Commission of Shanghai Municipality (Grant No. 22ZR1444100).

Lasing and fluorescence of air plasma in presence of an external electric field

Kai-Lu Wang(王凯璐), Hai-Cheng Mei(梅海城), Liang Xu(许亮), and Yi Liu(刘一)†   

  1. Shanghai Key Laboratory of Modern Optical System, University of Shanghai for Science and Technology, Shanghai 200093, China
  • Received:2025-02-28 Revised:2025-05-22 Accepted:2025-06-04 Online:2025-08-21 Published:2025-08-28
  • Contact: Yi Liu E-mail:yi.liu@usst.edu.cn
  • Supported by:
    Project supported by the Natural National Science Foundation of China (Grant Nos. 12034013 and 12204308) and Science and Technology Commission of Shanghai Municipality (Grant No. 22ZR1444100).

摘要: Cavity-free lasing of nitrogen molecules pumped by intense femtosecond laser pulses holds the potential for remote sensing of electric fields. Here we compared the influence of an external direct current (DC) electric field on both the directional lasing radiation and omnidirectional fluorescence emission of neutral nitrogen molecules. It was found that the forward lasing radiation in both pure nitrogen gas and ambient air shows a sensitive dependence on the direction and strength of the DC field, while the fluorescence is not influenced. The effect of pump laser polarization was also investigated. The distinct behavior of the lasing and fluorescence in response to the DC field was attributed to their different dependences on the population distribution of excited nitrogen molecules. This study consolidates the method for standoff detection of electric field with an air lasing effect in the atmosphere.

关键词: femtosecond filamentation, air plasma, remote sensing

Abstract: Cavity-free lasing of nitrogen molecules pumped by intense femtosecond laser pulses holds the potential for remote sensing of electric fields. Here we compared the influence of an external direct current (DC) electric field on both the directional lasing radiation and omnidirectional fluorescence emission of neutral nitrogen molecules. It was found that the forward lasing radiation in both pure nitrogen gas and ambient air shows a sensitive dependence on the direction and strength of the DC field, while the fluorescence is not influenced. The effect of pump laser polarization was also investigated. The distinct behavior of the lasing and fluorescence in response to the DC field was attributed to their different dependences on the population distribution of excited nitrogen molecules. This study consolidates the method for standoff detection of electric field with an air lasing effect in the atmosphere.

Key words: femtosecond filamentation, air plasma, remote sensing

中图分类号:  (Effects of atomic and molecular interactions on electronic structure)

  • 31.70.-f
34.50.Gb (Electronic excitation and ionization of molecules) 34.90.+q (Other topics in atomic and molecular collision processes and interactions) 52.38.-r (Laser-plasma interactions)