PROPAGATION OF GAUSSIAN BEAMS IN NONLINEAR AND RADIALLY INHOMOGENEOUS ABSORBING MEDIUM WITH ARBITRARY NONLINEARITY

A steady state analysis of self focusing of gaussian laser beams in a saturating nonlinear and radially inhomogeneous medium has been presented. The intensity dependent nonlinear part of the dielectric constant has been chosen to be arbitrarily large. Taking linear absorption into account and following the approach of Akhmanov and Sodha a beam width equation has been obtained. Various cases with radial inhomogeneity and different beam powers have been investigated. Three distinct cases have been identified. In one case the beam diverges from the very beginning; in the second case the medium behaves as an oscillatory wave guide for part of the path of propagation and in third it behaves as an oscillatory wave guide throughout.