Dual-band absorption due to simultaneous excitation of TE and TM modes in ITO-ES metamaterial for IR stealth technology

Abstract

We proposed a plasmonic based Indium Tin Oxide Embedded Silver (ITO-ES) infrared dual-band perfect absorber for the utilization in IR stealth technology. The proposed structure comprised of nano size Ag ring and desk embedded in ITO. The optical losses in optical regime of nanoscale plasmonic Ag were incorporated in terms of collision frequency using the modified Drude model. The optical response of the proposed structure was predicted by exciting it with a planwave using full wave vector frequency domain solver by employing Finite Element Method (FEM) in Computer Simulation Technology (CST) Microwave Studio. The simultaneous excitation of higher order transverse electromagnetic (TE and TM) modes in the proposed structure lead to high values of both absorption and Front to Back ratio (FTBR). The controlled and selective wavelength multiband absorption is crucial for IR stealth technology. The proposed metamaterial structures exhibit dual-bands IR absorption at wavelengths λ = 1.40 μm and 6.4 μm. First absorption peak suppresses the back scattering of the laser used by laser guided devices for detection, while the second peak suppresses the IR signature of the structure due thermal radiation which can be used by tracking devices to detect warm/hot objects.