Laser beam propagation in non-linearly absorbing media

Abstract

Many analytical techniques exist to explore the propagation of certain laser beams in free space, or in a linearly absorbing medium. When the medium is nonlinearly absorbing the propagation must be described by an iterative process using the well known Kirchoff–Fresnel diffraction equation. In this paper Gaussian and super-Gaussian beam shapes are propagated both through free space, and through a nonlinearly absorbing medium. The results show that shape invariance during propagation is dependent on the medium under consideration, and the authors find that super-Gaussian fields are shape invariant in certain nonlinearly absorbing media.