Graphene-based tunable triple-band plasmonic perfect metamaterial absorber with good angle-polarization-tolerance

In this paper, a new graphene-based tunable triple-band plasmonic perfect metamaterial absorber which is composed of two groups of graphene elliptical ring resonators and a gold plate separated by a dielectric layer is presented. The two sets of graphene elliptical ring resonators are connected to each other, so their internal parameters can be easily adjusted by voltage, which can dynamically control the absorptive characteristics of graphene metamaterials. In addition, the proposed absorber shows a very good angle-polarization-tolerance because of the high symmetry of the structure configuration. The results show that this kind of symmetrical double ellipse structure can produce three highly effective absorption peaks which are respectively at around 38.7 mu m, 20.2 mu m and 12.8 mu m and the value of peaks can even reach more than 99%. Moreover, due to the strong tunability, our absorber has a great potential in infrared and terahertz detection.