The main purpose of this study is to find the wave path of a beam wave in an inhomogeneous medium in which the permittivity is assumed to decrease linearly in one direction. A two-dimensional Gaussian beam is considered which can be described as a superposition of a number of plane waves. Variations of amplitude of the beam are illustrated. There are some differences between the path of the beam and the ray path obtained by Fermat’s principle.
© 1976 Optical Society of AmericaPDF Article