Backward air lasing actions induced by femtosecond laser filamentation: influence of population inversion lifetime

Abstract

We experimentally investigate generation of backward 357 nm N2 laser in a gas mixture of N2/Ar using 800-nm femtosecond laser pulses, and examine the involved gain dynamics based on pump-probe measurements. Our findings show that a minimum lifetime of population inversion in the excited N2 molecules is required for generating intense backward nitrogen lasers, which is ~0.8 ns under our experimental conditions. The results shed new light on the mechanism for generating intense backward lasers from ambient air, which are highly in demand for high sensitivity remote atmospheric sensing application.

arXiv comment18 pages, 5 figures

References in corpus (4)

• High gain backward lasing in air
• High-brightness switchable multi-wavelength remote laser in air
• Backward stimulated radiation from filaments in Nitrogen gas and air pumped by circularly polarized 800 nm femtosecond laser pulses
• Remote creation of strong and coherent emissions in air with two-color ultrafast laser pulses