A low loss platform for subwavelength terahertz graphene plasmon propagation

Abstract

Terahertz (THz) waves are assumed to be the candidate for next generation wireless communication owing to the broad frequency band and high channel capability. In order to accommodate the high data transfer rate, THz communication devices with high efficiency are in urgent need. Besides, the seamless connections between optical fibers and THz devices are also of great importance for on-chip THz propagating and manipulation. Here we propose a semiconductor nanowire (GaAs) based hybrid graphene plasmon waveguide, and realize a platform supporting graphene plasmon modes with low loss and strong optical energy confinement. Investigation on the influence of modal properties on nanowire geometrical shapes and orientations, key geometric parameter, Fermi energy level and carrier mobility of graphene revealed an achievement of a good balance between mode confinement and propagation loss. Higher than 50% modulation in the propagation length is reported. The proposed structure is capable of realizing future THz communication components and tunable devices.