VIRTUAL RAYS AND APPLICATIONS

The subject of virtual rays and its application is introduced, for the first time in this country to our knowledge, as a new method in ray o ptics. The method of virtual rays uses a representation of the electro magnetic field in terms of a continuum of a special class of rays that do not obey the usual geometrical optics along the entire path of pro pagation. It yields, in the asymptotic limit as lambda --> 0, the corr ect field representation at caustics, shadow, and transition regions, i.e., in which geometrical optics and its extensions, such as the geom etrical theory of diffraction, fail. The method of virtual rays is use d to solve for the high-frequency diffraction from a perfectly or impe rfectly conducting semi-infinite wedge.