Strong and coherent forward emissions from molecules driven by femtosecond infrared laser pulses

  • Huailiang Xu*
  • , Jinping Yao
  • , Wei Chu
  • , Bin Zeng
  • , Jielei Ni
  • , Guihua Li
  • , Ya Cheng
  • , Zhizhan Xu
  • , Daniil Kartashov
  • , Skirmantas Alisauskas
  • , Audrius Pugzlys
  • , Andrius Baltuska
  • , Kaoru Yamanouchi
  • , See Leang Chin
  • *Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Strong narrow-band coherent emission lines of the B2Σ+ u –X2Σ+ g transition of N+ 2 in air and the A2Πu–X2Πg transition of CO+ 2 in CO2 gas are observed from filaments generated by intense infrared femtosecond laser pulses (1150– 2000 nm, <200 fs) in air. The coherent emission stimulated by self-generated third and/or fifth harmonics of the infrared femtosecond laser pulses is found to propagate in the forward direction along the infrared laser beam and has the same polarization direction as the third and fifth harmonics serving as the seed light. The intensity of the strong forward emissions of N+ 2 and CO+ 2, exhibiting excellent temporal and spatial coherence properties, is two orders of magnitude stronger than that of the fluorescence of molecules, and is strongly dependent on the pump laser intensity, the intensity of the seed harmonic radiation, and the filament length. The possible mechanisms responsible for the generation of the strong coherence emissions are discussed.

Original languageEnglish
Pages (from-to)95-109
Number of pages15
JournalSpringer Series in Chemical Physics
Volume106
DOIs
StatePublished - 2014
Externally publishedYes

Fingerprint

Dive into the research topics of 'Strong and coherent forward emissions from molecules driven by femtosecond infrared laser pulses'. Together they form a unique fingerprint.

Cite this