Investigations of the properties of filaments generated in gas mixtures pumped by femtosecond laser pulses

Abstract

In this paper, we compare the properties of filaments generated in a Ne–N2 mixture, pure N2, a Kr–N2 mixture, and a Xe–N2 mixture pumped by femtosecond laser pulses systematically. Due to different nonlinear refractive indices and ionization potentials of these noble gases, the clamped intensity and plasma density can be tuned in a certain range when small amounts of different noble gases are injected into pure N2. In addition, we also demonstrate that a higher proportion of noble gas and shorter incident pulse duration can have the benefit of manipulating the plasma density on a relatively larger scale.