Multi-band terahertz two-handed metamaterial based on the combined ring and cross pairs

We present the design of a Multiband two-handed metamaterial (MM) with the composite structure combined ring and cross pairs (RP + CP) in the terahertz regime. The dual-band left-handed and single-band right-handed transmission properties of this composite structure were explored by the FDTD method. The MM exhibits left-handed and right-handed transmission pass bands around the frequencies of 0.43 THz, 1.32 THz and 0.85 THz for the terahertz electromagnetic (EM) wave normal incidence, respectively. The surface currents distributions are demonstrated to discuss the physical mechanism of the left-handed properties of the proposed MM. The retrieved equivalent EM parameters and the refraction phenomenon based on a wedge-shaped model verify the left-handed properties. Furthermore, the dual-band left-handed transmission properties of RP + CP structure can be tunable individually by changing the structural parameters. The presented design of terahertz two-handed MM offers a flexibility for investigation of their novel EM properties, and important terahertz device applications.