Infrared band ultra wideband metamaterial absorption device based on cylindrical multiscale resonator

Abstract

Mid-infrared and far-infrared regions broadband absorption is of great significance in science and technology. In this paper, we put forward a mid-far infrared metamaterial absorber, and Finite-Difference Time-Domain simulation calculation shows that the absorption rate in the 6.73-16.65 μm band, with an average absorption rate of 96.01%. At the same time, although the absorption performance depends on the polarization state and the incidence angle, it shows the relative stability in a wide angle range. Using the FDTD electromagnetic field analysis visualize the electric and magnetic field intensity distributions within the absorber, it can be known that the resonance mode of the absorber has surface plasmon resonance (SPR), localized surface plasmon resonance (LSPR), and Fabry-Perot cavity resonance. Meanwhile, adjusting the absorption layer thickness and the periodic geometry parameters can optimize the absorption performance. In addition, different microstructures and different top materials also have an influence on the absorption rate of the absorber. The absorber has high practical value in thermoelectric devices, infrared imaging and thermal detection.