Wave Propagation Through Quasi-Optical Irregularities*

Abstract

Diverse approximate solutions of Maxwell’s equations for propagation of plane electromagnetic waves through a layer of small dielectric irregularities which vary smoothly and slowly with respect to the wavelength, are compared. Regions of validity for each method in this quasi-optical realm are established, and modifications are made to account for energy conservation. The limitations on propagation distance and magnitude of the irregularities are less severe for the expressions which result from the Rytov complex-phase expansion than for those which result from WKB and first Born approximations (these are contained in the Rytov approximation). The results are presented most simply in the form of a parameter-space diagram.