Planar terahertz metamaterial with three-resonant frequencies

In this paper,we study a three-resonant metamaterial with the combination of dual-resonant and single-resonant metamaterials.We present a new method to design multi-resonant metamaterial,which has a smaller dimension than general symmetric and asymmetric multi-resonant metamaterials.Theoretical and experimental results show that the structure has three distinct absorption frequencies centering around 0.29 THz,0.46 THz,and 0.92 THz,and that each of them corresponds to a different resonant mode.Due to the good separation of the different resonances,this design provides a unique and effective method to construct multiband terahertz devices.