Bi-funtional resonance effects of plasmon-induced transparency and Fano-like response using an asymmetry metamaterial resonator consisting of three metallic strips at terahertz frequency

Bi-functional metamaterial resonance device operated at terahertz frequency is designed in this paper. It is composed of three metallic strips, in which two parallel metallic strips having the identical dimensions are arranged in the longitudinal direction, and a single metallic strip deviated from the center position is arranged in the horizontal direction. Bi-functional resonance effects of plasmon-induced transparency (PIT) and Fano-like response are simultaneously obtained in this simple metamaterial structure. The formation mechanisms of the two resonance effects are analyzed with the aid of the near-field distributions and the dependence of structure parameters on the whole resonance performance. Results further show that the metallic strip placed horizontally plays an important role in adjusting the resonance response of the metamaterial resonator. More importantly, when the deviation value of the metallic strip in the horizontal direction exceeds a certain amount, for example 10 mu m, the metamaterial resonator can realize the effective regulation from bi-functional resonance to single-functional PIT effect. Our proposed structure can be used as valuable platform for ideas to inspire the design of novel electro-optic devices.