DIFFRACTION GRATINGS IN UNIAXIAL CRYSTALS WITH ARBITRARY ORIENTATION OF THE OPTIC AXIS

We present a fully vectorial, rigorous electromagnetic approach to wave diffraction from one-dimensional periodic interfaces between isotropic and uniaxial media. The isotropic medium can be either a dielectric or a metal with losses, whereas the uniaxial medium is nonlossy, with its optic axis arbitrarily oriented with respect to the interface. Both media are magnetic. The incident wave vector can be associated with waves incident either from the isotropic or from the anisotropic side. Particular attention is devoted to the case of interfaces between a uniaxial dielectric and a metal illuminated from the anisotropic side. The examples include comparisons with a method invoking the Rayleigh hypothesis and the study of resonant excitation of surface plasmons at anisotropic interfaces.