Bidirectional terahertz plasmonic switch based on periodically structured graphene

Abstract

A plasmonic crystal structure is proposed and simulated based on graphene at terahertz frequency using the three-dimensional finite element method. The proposed model involves both an ON/OFF and a directional switch. Implementing a crystalline structure in graphene can enhance absorption since such a structure creates a bandgap wherein no propagation mode is allowed. Accordingly, the ON/OFF and directional switches can be designed with an extinction ratio higher than 30 dB. Other advantages of this structure are its high quality factor and small dimensions of 1 µm (for the ON/OFF switch) and 2 µm (for the directional switch).