Multi-band terahertz metamaterial absorber for sensing application

In this paper, we proposed a multi-band metamaterial absorber for sensing thin film, which consists of tri-layer structure: patterned multi-split electric ring resonators layer, dielectric spacer layer, and continuous metal ground layer. The calculated results demonstrated that the absorber can exhibit three distinctive absorption peaks with narrow bandwidth. As the surface of the absorber was coated with the analyte layer, moreover, the locations of three absorption peaks appear obvious redshift, and the corresponding maximal sensitivities are 0.119 THz/RIU, 0.248 THz/RIU, and 0.662 THz/RIU, respectively. Therefore, the proposed absorber has significant potential applications in detecting and sensing.