Enhancement of femtosecond laser-induced plasma fluorescence using a nanosecond laser

Research output: Contribution to journalArticle


We demonstrate the enhancement of femtosecond (fs) laser-induced filaments in air and nitrogen flow fields using a nanosecond (ns) laser. With the ns laser being imposed on the filaments, the length and the emission intensity of the filaments were largely increased. Temporally resolved spectra of the enhanced filaments were obtained. The results show that the ns laser enhanced the short-lifetime fluorescence of nitrogen, which comes from the transition processes of N 2 + (B 2 Σ u + - X 2 Σ g + ), N 2 (B 3 Π g - A 3 Σ u + ) and N 2 (C 3 Π u - B 3 Π g ). However, it had little effect on the long-lifetime chemiluminescence, which mainly comes from reactions such as N 2 (A 3 Σ u + ) + N 2 (A 3 Σ u + ) → N 2 (X 1 Σ g + , v = 0) + N 2 (B 3 Π g ). A possible explanation of this phenomenon is given, and this phenomenon might have potential applications in instantaneous one-dimensional measurements of various species in gas flow fields.


  • Xiaofeng Li
  • Bo Li
  • Jixu Liu
  • Zhifeng Zhu
  • Dayuan Zhang
  • Yifu Tian
  • Qiang Gao
  • Zhongshan Li
External organisations
  • Tianjin University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics
Original languageEnglish
Pages (from-to)5755-5763
Number of pages9
JournalOptics Express
Issue number4
Publication statusPublished - 2019
Publication categoryResearch