Design of a Novel Dual-Band Terahertz Metamaterial Absorber

We present a novel dual-band terahertz absorber formed by only a patterned U-shaped metallic ring and a metallic ground plane separated by a dielectric layer. Theoretical results show that the proposed absorber has two distinct absorption bands whose peaks are average over 98 %. Different from previous reports by combining the resonances of the complex structure (coplanar super-unit structure or stacked structure) to obtain the dual-band response, the proposed structure utilizes the LC resonance and dipolar response of the single patterned structure and thus making the proposed structure quite easy to be fabricated. The roles of the geometric parameters are investigated to explain the principle of absorption. Furthermore, the proposed concept applies to other types of absorber structure and can be readily extended to other frequency regimes for a host of applications such as detection, imaging, sensing, and selective thermal emitters.