Design of Broadband Plasmon-Induced Transparency Hybrid Metamaterial Based on the Interaction of the Metal and Dielectric Resonances

In this paper, a broadband plasmon-induced transparency (PIT) hybrid metamaterial system (HMS) is realized and numerically demonstrated via the interference between different resonance modes of metal and dielectric resonators. The employed PIT HMS supports a strong near-fired coupling between unit cells consisting of eight TiO2 nested split rings (dark plasmonic resonators) surrounded by four metal cut wires (bright plasmonic resonators) embedded in the intermediate dielectric layer, and a broad transparency window which is higher than 0.9 is obtained from 0.61 to 0.76 THz with a relative bandwidth of 21.9%. In the transparent window, the drastic change of phase leads to high group delay, and the remarkable slow light phenomenon can be clearly observed. The maximum of the group delay and group index can reach 528 ps and 2880, respectively. The localization distributions of the electromagnetic field intuitively exhibit the generation and action process of destructive interference. The theoretical investigation of the two-oscillator model further confirms the effectiveness and consistency of the simulation results. In addition, the fourfold symmetric of the proposed PIT HMS supports the liberation from the dependence of incident polarization form. Such an implementation opens a new path for the designing of filtering, switching, and data storing devices.