Tunable Plasmonic Filter Based on Graphene Split-Ring

We propose in this paper a tunable plasmonic filter based on graphene split-ring (GSR) resonator. It is found the resonances could be classified into two categories, i.e., even-parity and odd-parity mode according to the symmetry of field profile in GSR. The coupling between graphene nanoribbon and GSR is GSR-orientation sensitive, and the odd-parity mode presents a greater sensitivity due to its asymmetric field profile. The transmission spectrum of the proposed filter could be efficiently modified by tuning the shape, orientation, and Fermi level of GSR. The proposed structure can be applied in the tunable ultra-compact graphene plasmonic devices for future nanoplasmonic applications.