Propagation of a Gaussian Beam in Planar and Cylindrically Inhomogeneous Media: Comparison of Modal Analysis and Approximate Approaches

Abstract

This work presents a study on the propagation of electromagnetic waves in media, characterized by f = EO -EZy 2 and E=EE-E2r 2 .A vector theory based on Maxwell's equations is used to derive linear homogeneous second-order equations satisfied by the transverse electric and magnetic field components . The various modes of propagation and the corresponding propagation constants have been determined . These are used to study the propagation and focusing of waves which have an intensity distribution along their wavefront .An alternative method for the study of the propagation and focusing of electromagnetic waves has been discussed . This is based on an approximate solution of the wave equation given in previous communications . For parameters of interest, the results obtained from the approximate solution are in excellent agreement with the solution obtained from the modal analysis of the problem .The present study should be of relevance in tropospheric communication and focusing of laser beams in selfoc fibres, gas lenses, etc .