Energy light structures during femtosecond laser radiation filamentation in air. To the 50th anniversary of the first paper about light self-focusing

Abstract

A class of energy light structures in nonlinear wave physics, so-called diffraction-beam tubes in a self-focusing dissipative medium, has been studied. It is shown that their interaction along a high-power femtosecond laser radiation propagation path produces areas of light energy localization, stable in physical characteristics, i.e., a filament and a post-filamentation channel, as well as an energy-conservative periphery. Stabilization of boundaries of the above areas is provided by additional contraction of a diffractive nature from the side of the periphery. The dependencies of filamentation length of a laser pulse on the power and beam radius and the fact of high intensity conservation in the post-filamentation light channel are interpreted using this concept.