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

Abstract

Broadband absorption in the mid-infrared and far-infrared regions is of great significance in science and technology. Herein, we developed a mid-far infrared metamaterial absorber, and finite-difference time-domain simulation calculations showed that its average absorption rate in the 6.73–16.65 μm band was 96.01%. At the same time, although its absorption performance depended on the polarization state and incidence angle, it showed relative stability in a wide angle range. FDTD electromagnetic field analysis enabled the visualization of the electric and magnetic field intensity distributions within the absorber, demonstrating that the absorber exhibits multiple resonance modes, including surface plasmon resonance (SPR), localized surface plasmon resonance (LSPR), and Fabry–Perot cavity resonance. Meanwhile, adjusting the thickness of the absorption layer and the periodic geometry parameters enabled the optimization of the absorption performance of the developed absorber. In addition, different microstructures and different top materials had an influence on its absorption rate. Thus, the developed absorber has high practical value for application in thermoelectric devices, infrared imaging and thermal detection.