Broadband and highly absorbing multilayer structure in mid-infrared

In this paper, we have designed and experimentally demonstrated a broadband absorber in the mid-infrared region based on the impedance matching method. The absorber is made of planar multilayered dielectric and metallic films without involving lithography in fabrication. Our measurements reveal high absorption over 85% in the wavelength range of 2.2-6.2 μm. This wideband absorption is shown to be independent of the polarization and can be maintained over a range of incident angles up to 45°. The resultant absorber has potential applications for thermal shielding, camouflaging, sensing, etc.