Broadband tunable mid-infrared absorber based on conductive strip-like meta-atom elements

A metamaterial composed of thin metallic strips as an efficient broadband absorber in the mid-infrared spectrum is investigated. Here matching between dielectric and geometrical properties individual elements critical to ensure high absorption. Detailed theoretical analysis based on electric dipole approximation performed characterize absorption scattering unit cell results are used design such configurations. The cross-section a strip-shaped element can exceed its longitudinal area by 17 times. It was shown that absorptance Ni-based metal-insulator-metal (MIM) structure 90 % about 8.2 - 18 um spectrum. associated with excitation low-Q-factor modes strips. Such demonstrates good polarization incident angle tolerance for transverse-electric (TE) waves. be tuned varying parameters.