Adding a Tuneable Response to a Terahertz Metasurface Using a Graphene Thin Film

Tuneable terahertz devices are pivotal for the next-generation high-speed wireless communications and sensing technologies. The development of these devices is in its infancy, as significant challenges exist in fabricating terahertz electronics that possess tuneability while maintaining an ultrafast electrical response. In this work, a graphene film is employed as a tuneable conductive ground plate for a gold terahertz metasurface. In this way, a tuning functionality is added to the otherwise non-tuneable metasurface. Using this approach, a proof-of-concept THz transmission modulator is designed, modelled, and experimentally fabricated. The experimental device output is consistent with the simulation. Electrical bias connections are made laterally on the graphene ground, simplifying the fabrication process. This delivers a new and simple approach of adding a tuning functionality to a wide range of terahertz devices.