Selective excitation of resonances in gammadion metamaterials for terahertz wave manipulation

A gammadion terahertz （THz） metamaterial embedded with a pair of splits is experimentally investigated. By introducing the pair of splits at different arms, the transmitted amplitude at the resonance frequency can be manipulated from 61% to 24%. Broadband static resonance tunability from 1.11 to 1.51 THz is also demonstrated via varying the relative split positions at certain arms. The amplitude change and static resonance tunability are attributed to the introduced split pairs, which enable se- lective excitation of different resonance modes in the gammadion metamaterials. This work promises a new approach to design THz functional devices.