Metamaterial-inspired high-absorption surfaces for thermal infrared applications

Abstract

We present design, fabrication, and characterization results of a highly absorptive surface in the thermal infrared that draws on concepts from the frequency selective surface and metamaterials communities. At normal incidence this optically thin surface has an absorption of over 99%. Furthermore, it has a broad angular range (over 90% absorption at 60 degrees from normal). The simple structure is composed of a reflective metal layer, a roughly quarter-wave layer of lossy dielectric, and a top metal layer that is patterned with an array of subwavelength apertures. The design of the aperture allows spectral and angular control of the absorption/emission band. We will present simulation and measured results. Change in waveband and polarization could easily be changed from pixel to pixel in a focal plane array.