Terahertz metamaterial using reconfigurable H-shaped resonator with tunable perfect absorption characteristic

Abstract

A design of H-shaped tunable metamaterial absorber (HTMA) is proposed to show multi-resonance and tunable perfect absorption characteristics. It consists of a reconfigurable H-shaped Al resonator suspended on the bottom Al layer. HTMA shows multi-resonance characteristic that can be actively tuned by reconfiguring the H-shaped resonator. The transverse magnetic (TM) responses can be switched from single perfect absorption resonance at 3.04 THz to dual perfect absorption resonances at 3.22 THz and 4.82 THz. While the transverse electric (TE) responses exhibit triple-resonance with great tunability. The corresponding quality factor (Q-factor) and sensitivity are calculated. The sensitivities are 1.16 THz/RIU, 1.76 THz/RIU, 1.27 THz/RIU, 2.24 THz/RIU, and 2.94 THz/RIU for dual-resonance in TM mode and triple-resonance in TE mode, respectively. In consideration of the above optical characteristics, it can be used for the sensing application when the device is exposed to different surrounding refractive index. These results indicate the potential of the proposed HTMA to be applied in optical gas sensors, biosensors, and polarization switches.