Triple-band terahertz metamaterial absorber using the nesting structure of two pairs of splitting arcs

Abstract

This paper presents the design of triple-band terahertz metamaterial absorber, whose surface structure is a nested-type metallic pattern composed of two pairs of splitting arcs, of which the inner two splitting arcs have the same but smaller size, while the outer two possess the same but larger dimension. The surface patterned structure can strongly interact with the incident terahertz beam, resulting in three narrow-band and discrete resonance peaks having higher than 94% absorption rates. Near-field patterns of the three absorption peaks are discussed to insight into the physical mechanism of these peaks, it is revealed that the first two absorption peaks result from the dipole resonance of the inner two splitting arcs and outer pair of splitting arcs, respectively, while the last absorption peak is caused by surface propagation resonance of the surface patterned resonator. The effect of structure parameters, including the sizes of splitting arcs and the spacing between two pairs of splitting arcs, on the absorption properties, is further analyzed. The absorber suggested here could provide guidance for the design of multiple-band metamaterial absorbers, and could find great application prospects in terahertz technology-related areas.