Plasmon-induced transparency in terahertz planar metamaterials

A planar metamaterial structure with plasmon-induced transparency effect in terahertz region is proposed and systematic numerical study is presented in this paper. The metamaterial structure is comprised of two different spilt-ring resonators in the same plane. With the destructive interference coupling between these two split-ring resonators, the proposed metamaterial structure exhibits a large transparency window within a broad absorption spectra. Moreover, the origin of transparency window with extremely low absorption and strong dispersion is clarified by two coupled Lorentzian resonators analytical model, and verified by accurate simulation of the electromagnetic wave propagation in the metamaterial structure. The proposed metamaterial opens up the avenue to design micro-sized functional devices used in switching, modulation, and slowing down terahertz waves.