中国物理B ›› 2015, Vol. 24 ›› Issue (1): 13301-013301.doi: 10.1088/1674-1056/24/1/013301

所属专题: TOPICAL REVIEW — Ultrafast intense laser science

• TOPICAL REVIEW—Ultrafast intense laser science • 上一篇    下一篇

Population inversion in fluorescing fragments of super-excited molecules inside an air filament

徐淮良a, See Leang Chinb   

  1. a State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China;
    b Department of Physics, Engineering Physics and Optics & Center for Optics, Photonics and Laser (COPL), Laval University, Québec, QC, G1V 0A6, Canada
  • 收稿日期:2014-06-03 修回日期:2014-11-25 出版日期:2015-01-05 发布日期:2015-01-05
  • 基金资助:

    Project supported by the Canada Research Chairs, the Natural Science and Engineering Research Council of Canada (NSERC), the FRQNT, the Canada Foundation for Innovation (CFI), the National Basic Research Program of China (Grant No. 2014CB921300), the National Natural Science Foundation of China (Grant No. 61235003), the Research Fund for the Doctoral Program of Higher Education of China, and the Scientific Research Foundation for Returned Scholars, Ministry of Education of China.

Population inversion in fluorescing fragments of super-excited molecules inside an air filament

Huai-Liang  Xua, See Leang Chinb,   

  1. a State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China;
    b Department of Physics, Engineering Physics and Optics & Center for Optics, Photonics and Laser (COPL), Laval University, Québec, QC, G1V 0A6, Canada
  • Received:2014-06-03 Revised:2014-11-25 Online:2015-01-05 Published:2015-01-05
  • Contact: Huai-Liang Xu E-mail:huailiang@jlu.edu.cn
  • Supported by:

    Project supported by the Canada Research Chairs, the Natural Science and Engineering Research Council of Canada (NSERC), the FRQNT, the Canada Foundation for Innovation (CFI), the National Basic Research Program of China (Grant No. 2014CB921300), the National Natural Science Foundation of China (Grant No. 61235003), the Research Fund for the Doctoral Program of Higher Education of China, and the Scientific Research Foundation for Returned Scholars, Ministry of Education of China.

摘要:

An original idea is reviewed. When a molecule is pumped into a super-excited state, one of its decay channels is neutral dissociation. One or more of the neutral fragments will fluoresce. Hence, if a lower state of such fluorescing fragments was populated through other channels but with a lower probability, population inversion of the fluorescing fragments would be naturally realized. This idea seems to be validated, so far, by comparing published work on three hydrocarbon molecules, CH4, C2H2, C2H4, and water vapor, H2O. After super-excitation in a femtosecond laser filament in air mixed with these molecules, the fluorescence from the CH or OH fragments exhibits population inversion, i.e., amplified spontaneous emission was observed in the backscattering direction of the filament.

关键词: femtosecond filament, lasing, super-excited states

Abstract:

An original idea is reviewed. When a molecule is pumped into a super-excited state, one of its decay channels is neutral dissociation. One or more of the neutral fragments will fluoresce. Hence, if a lower state of such fluorescing fragments was populated through other channels but with a lower probability, population inversion of the fluorescing fragments would be naturally realized. This idea seems to be validated, so far, by comparing published work on three hydrocarbon molecules, CH4, C2H2, C2H4, and water vapor, H2O. After super-excitation in a femtosecond laser filament in air mixed with these molecules, the fluorescence from the CH or OH fragments exhibits population inversion, i.e., amplified spontaneous emission was observed in the backscattering direction of the filament.

Key words: femtosecond filament, lasing, super-excited states

中图分类号:  (Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states))

  • 33.80.Rv
42.65.Re (Ultrafast processes; optical pulse generation and pulse compression) 33.20.Xx (Spectra induced by strong-field or attosecond laser irradiation)