Global Self-Focusing and Features of Multiple Filamentation of Radiation of a Subterawatt Ti:Sapphire Laser with a Centimeter Output Aperture Along a 150-m Path

Abstract

The formation and propagation of postfilamentation channels along a controllable path 150 m long are studied experimentally for collimated beams of different diameters. During multiple filamentation, a laser beam is compressed into a global focus, after passing which its angular divergence is much greater than the divergence of postfilamentation channels generated during the filamentation. It is shown that the intensity of the postfilamentation channels is sufficient for starting multiple filamentation in optical elements at distances much longer than the filamentation region length.