Vol. 26, issue 01, article # 2

Abstract:

The single (axial) filamentation regime of high-power collimated femtosecond laser radiation in the atmosphere is theoretically investigated. The effect of laser beam initial diameter on characteristics of a filament is analyzed. We consider three filament parameters: the coordinate of the filament beginning, its length and longitudinal continuity. We found that for the same initial beam power all the above characteristics of filaments show the dependence on the beam radius. As the main physical cause for this circumstance the diffraction interaction of various beam areas during the filamentation process is considered; the strength of this interaction increases as the beam widens.

Keywords:

ultrashort laser radiation, self-focusing, filamentation, light rays