Abstract

The effect of long-distance apparently self-guided femtosecond pulse propagation in air [1] has attracted considerable attention. The self-guiding of the intense laser pulse in gaseous media appears to be a result of balance between two competing nonlinear effects: Kerr type, leading to selffocusing, and defocusing by of the electron plasma created due to multiphoton ionization [2]. In that way a single finite filament, or optical light bullet, with diameter of some tens of micrometers is formed. Even with power well above the critical one for the Kerr self-focusing, the collapse of the beam is prevented, and the filament preserves its shape over tens of meters of propagation. Moreover, recent investigations show that under certain initial conditions the spatiotemporal soliton generation in gasses is possible [3].

© 2001 EPS