▎ 摘　　要

In this Letter, a graphene-based terahertz plasmonic waveguide is proposed. The proposed structure benefits from the enhanced confinement and increased attenuation length of graphene surface plasmon by placing the graphene sheet in proximity of metal layers. For a graphene-based slab waveguide, our data show a 20% increase in the plasmonic attenuation length and a 97% increase in the attenuation length normalized to the plasmonic wavelength, thus significantly increasing the propagation distance of the surface plasmon. Further, improvement is possible by optimizing dielectric mismatch, graphene-metal distance, waveguide width, and the Fermi energy of graphene. (C) 2014 AIP Publishing LLC.