Nonlinear Evolution of q-Gaussian Laser Beams in Preformed Parabolic Plasma Channels

Theoretical investigation on nonlinear propagation characteristics of q-Gaussian laser beams in preformed parabolic plasma channels has been presented. The optical response of the channel has been modelled by ponderomotive nonlinearity. Following Virial theorem in W.K.B approximation, semi analytical solution of the wave equation for the field of laser beam has been obtained. Particularly the evolutions of beam width and axial phase of the laser beam have been investigated in detail. Self trapping of the laser beam arising as a consequence of the cancellation of diffraction broadening by nonlinear refraction of the laser beam has also been investigated.