▎ 摘　　要

We have proposed and investigated an ultra-compact graphene-based plasmonic device, where the propagation direction of SPP can be controlled flexibly by changing the chemical potential of graphene. The plasmonic devices with numerous functions, including splitter and router, could be realized by manipulating graphene SPP propagation direction. The designed structure is essential for the photonic integration system, including nano scale multiplexers, multifunctional devices, and on-chips routing system.