Fano resonances induced by the asymmetry due to defect in the corrugated disk resonator

We proposed a novel planar meta-atom structure supporting higher order Fano resonances. The unit cell consists of a plasmonic defective corrugated metallic disk (CMD). The numerical and experimental results reveal that higher order Fano resonances can be generated at terahertz frequencies when symmetric CMD is broken with small defective angle. Such higher order Fano resonances result from the coupling between the bright dipolar mode evoked by the edge of the wedge-shaped slice and the dark multipolar spoof localized surface plasmon(LSP) modes. Our investigation may be applicable to metamaterial resonators with multiple functionalities and high performance, multi-bio sensing, terahertz integration, micro resonator design, terahertz communication, and so on.