Scattering by lossy material coated periodic gratings under oblique incidence

A numerical approach to the study of material coated two-dimensional periodic gratings under oblique incidence is presented. The boundary integral method is used to characterize the complex contour of a single groove (or period) of the grating. The underlying periodicity of the infinite structure is then accounted for by applying periodic boundary conditions and expanding the fields in terms of Floquet harmonics. The authors present numerical results and a discussion of how the groove profile can be used to alter the absorbing characteristics of lossy coatings.<>