Thermal emission control by evanescent wave coupling between guided mode of resonant grating and surface phonon polariton on silicon carbide plate

Dielectric guided mode resonant gratings exhibit a sharp spectral and angular response of high reflectivity for propagation wave, and strong evanescent waves are excited. We show that in such a resonant grating positioned above the silicon carbide (SiC) plate, incident light is absorbed in the SiC plate via the evanescent wave coupling when the lateral wavenumber of a guided mode of the grating coincides with that of surface phonon polaritons on the SiC plate. This coupling scheme using the thermally transparent grating enables a sharp spectral and angular emission in the infrared region with capabilities of emissivity modulation and spatially asymmetric emissivity. Thermally transparent subwavelength structures electromagnetically coupled to polar material thermal bodies are crucial in enabling components for thermal emission control. (C) 2014 AIP Publishing LLC.