Theory of subwavelength hole arrays coupled with photonic crystals for extraordinary thermal emission

A subwavelength array of holes in a metal film residing on a silicon photonic crystal exhibits very sharp resonant absorption modes and extraordinary thermal emission. We developed a rigorous electromagnetic theory of subwavelength emitters based on the scattering matrix approach. Simulations exhibit a resonant absorption and emission when the photonic crystal is present, in good agreement with measurements. Diffraction resonances are found within the silicon photonic crystal. These combine with the extraordinary transmission through subwavelength hole arrays to generate resonant absorption in subwavelength arrays of metallodielectric photonic crystals. There is enormous enhancement of fields within the holes for resonant emissive modes.