Tailored metal-insulator-metal multilayer design for perfect ir absorption at desired wavelengths in stealth systems

The plasmonic-based metamaterial has been designed with a metal-insulator-metal (MIM) structure for applying IR stealth technology. The design of two MIM unit cell structures was composed of five stacked layers. The numerical simulation showed that the designed MIM structure exhibited dual absorption peaks at resonant wavelengths of 1.3 µm and 6.7 µm and the absorptivity of both peaks reached to 98% and 96%. The first absorption peak has decreased the scattering of IR laser beams, frequently employed for detection by laser-guided devices, while the second peak represented to reduction of heat waves from the surface. Due to multiple excitations of surface plasmon at the silver-dielectric interface inside the MIM structure, the absorptivity was higher than 80% in the band 1-2 μm. Using the Finite-Difference-Time-Domain (FDTD) in computer simulation technology (CST) microwave studio, the optical resonant behavior of the designed plasmonic-based MIM structure was predicted by activating it with a plane wave using a frequency domain solver. The simultaneous excitation of electric and magnetic fields at the silver-dielectric interface has led to a high value of absorptivity with minimal backward scattering at resonant wavelength.