PROPAGATION OF POWERFUL SUBPICOSECOND LASER PULSE IN GASES UNDER IONIZATION CONDITIONS

The transformation of space-time characteristics of a high intensive subpicosecond laser pulse, propagating in gases, is investigated in the paper aiming at the construction and substantiation of physical models of the non-linear-optical interaction of powerful laser pulses with gas media, describing effects of the phase self-modulation of a pulse, the non-linear distortion of a beam profile, the forced combination scattering. As a result the multidimensional non-stationary problem about the self-action of a subpicosecond laser pulse in gases under conditions of the mutual influence of kerr and plasma non-linearities has been investigated for the first time. The origin of the space-time instability of radiation, instability developing in inert gases of atmospheric density because of the mutual influence of effects of the diffraction and non-stationary non-linear refraction in self-guided plasma, has been established. The qualitative correspondence of experimental and calculation characteristics of a pulse has been obtained. The model of the forced combination scattering of electron oscillations of laser plasma of a subpicosecond laser pulse has been constructed. The estimation of the contribution of the forced combination scattering into a spectrum of a laser pulse has been given. The paper results may find their field of application in the analysis of non-linear-optical processes and in the obtaining of the space-time distribution of laser intensity in gas under conditions of a real experimentAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio