Flat metal-dielectric grating with 100% retro-diffraction efficiency: rigorous theory

We have recently designed a new type of a flat metal-dielectric grating which is supposed to replace blazed diffraction gratings, providing very high −1st reflected diffraction order efficiency within a broad wavelength band, high durability, and relative ease of fabrication. In this communication we present a rigorous electromagnetic theory of the grating in the approximation of infinitely thin perfect metal and show that the properly designed grating can reach 100% diffraction efficiency in the Littrow configuration for either transversal electric (TE or s) or transversal magnetic (TM or p) polarizations. Properties of the grating are analysed and discussed in detail. (paper)