Possibility of control of propagation regime in medium with cubic nonlinearity for chirped femtosecond pulse under the temporal dispersion of nonlinear response

摘要

This report deals with self-focusing of axial symmetric laser beam in Kerr medium with the temporal dispersion of nonlinear response. Laser beam propagation is described by so-called generalized nonlinear Schrodinger equation in 3D case. The essential feature of this equation is a term, which contains a time derivation from nonlinear response. As a result, a group velocity of wave packet depends on laser pulse intensity. On the other hand, as well known, self-focusing of an axial symmetric laser beam results in unlimited growth of its intensity for the picoseconds diapason of pulse duration. Action of both factors gives a new quality of laser beam propagation. Its main feature is a possibility to control of self-action for chirped laser pulse. Under certain conditions, we can easy to change regime of self-focusing to opposite one. Temporal dispersion of nonlinear response can be the main nonlinear response of medium under the laser light propagation.