Ray Optics for Radiation Problems in Anisotropic Regions With Boundaries

Based on a rigorous integral representation, the far fields radiated by an electromagnetic point source in the presence of a planar interface between two arbitrary homogeneous, lossless, anisotropic half spaces are evaluated. An invariant ray‐optical interpretation is given to the stationary point contributions (direct, reflected, or transmitted rays) and to the branch curve contributions (lateral rays) to the asymptotic evaluation. The invariant form of the results highlights the local character of the ray‐optical fields and permits one to postulate a generalization of the ray‐optical method of analysis to the problem of reflection and transmission at a gently curved interface, which is generally not amenable to a rigorous analysis. Based on a rigorous integral representation, the far fields radiated by an electromagnetic point source in the presence of a planar interface between two arbitrary homogeneous, lossless, anisotropic half spaces are evaluated. An invariant ray‐optical interpretation is given to the stationary point contributions (direct, reflected, or transmitted rays) and to the branch curve contributions (lateral rays) to the asymptotic evaluation. The invariant form of the results highlights the local character of the ray‐optical fields and permits one to postulate a generalization of the ray‐optical method of analysis to the problem of reflection and transmission at a gently curved interface, which is generally not amenable to a rigorous analysis.