Picosecond laser filamentation in air

Abstract

The propagation of intense picosecond laser pulses in air in the presence of\nstrong nonlinear self-action effects and air ionization is investigated\nexperimentally and numerically. The model used for numerical analysis is based\non the nonlinear propagator for the optical field coupled with the rate\nequations for the production of various ionic species and plasma temperature.\nOur results show that the phenomenon of plasma-driven intensity clamping, which\nis paramount in femtosecond laser filamentation, holds for picosecond pulses.\nFurthermore, the temporal pulse distortions are limited and the pulse fluence\nis also clamped. The resulting unique feature of the picosecond filamentation\nregime is the production of a broad, fully ionized air channel, continuous both\nlongitudinally and transversely, which may be instrumental for numerous\napplications.\n