ABSTRACT
We investigate the pressure effects on the propagation of the intense femtosecond laser pulse with wavelength of 800 nm by numerical simulations. We adopt the higher-order Kerr model and consider the effects on the on-axis intensity, the beam radius and the energy of the filament, as well as the on-axis electron density. Numerical results show that when the pressures increase, the filament appears later and ends earlier resulting in the shorter filament length. The cross-sectional radius of the filament becomes narrower with the increase of pressure. We also obtain the conclusion that the energy in the filament background energy pool increases when the pressure increases.
