Conical diffraction from index-matched gratings

Abstract

We study the diffraction of electromagnetic waves from a periodically corrugated interface between two index-matched dielectrics in the general case of oblique incidence. We show that the eigenmodes of the index-matched grating can be used to provide a strong degree of polarization conversion between p and s modes. The possibility of producing curves of specular reflectivity versus angle of incidence with arbitrarily close resonance peaks is investigated.