A known exact solution to Maxwell’s equations in a plane-stratified medium is shown not to be a traveling wave. The solution can be decomposed into two traveling fields that do not satisfy Maxwell’s equations separately. These fields are identified as the transmitted and return fields. The transmitted field is compared with the geometric-optics approximation: The phases of the two fields do not coincide. The reflectance of a layer of such a medium is calculated and shown to be the same as that obtained by the approximation of a graded profile.
© 1991 Optical Society of America
Bernard Jancewicz, "Plane electromagnetic wave propagating parallel to the gradient of the refractive index," J. Opt. Soc. Am. A 8, 1529-1535 (1991)