a three-dimensional broadband infrared metamaterial absorber based on the plasmonic and dipole resonance responses

In this paper, a three-dimensional, polarization-insensitive broadband metamaterial absorber in the infrared region is proposed. and the same kind of metal is used in the whole structure. the simulated results show that the structure can achieve a broadband absorption greater than 90% from 40.3 to 70.2 thz for either transverse electric or magnetic polarization mode at normal incidence. subsequently, due to the rotationally symmetric distributions of the structure in the z-axis, the proposed metamaterial absorber is independent for the different polarization angles. moreover, unlike previous resistive films metamaterial absorbers which are based on the resistive film for the absorption of the electromagnetic waves, and in this structure, the absorption are not based on the metal films themselves but based on resonance. in addition, through analysis of the electromagnetic field and the surface current distributions, it can demonstrate that the absorption mechanism of the absorber which is based on the surface plasmonic and dipole resonance responses. finally, we believe this idea also extends to other frequency regions and also can realize broadband absorption.