提出一种由硅-绝缘体（SOI）结构与涂覆石墨烯层的纳米线（GCNW）构成的低损耗波导结构，采用有限元方法详细研究波导结构中石墨烯等离激元基模传输特性对频率、几何参数、材料参数以及石墨烯化学势的依赖关系。仿真结果表明，该波导中低折射率的SiO2介质层可实现高性能的深度亚波长光约束。得益于低折射率的SiO2介质层和SOI衬底以及石墨烯层的高折射率对比度，可获得极小模场面积的低损耗等离激元模式。所提出的波导结构为高性能和深度亚波长可调谐集成光子器件的设计提供一定的参考。

A low-loss waveguide structure composed of a silicon-on-insulator （SOI） structure and graphene-coated nanowires （GCNW） is proposed. The dependences of the transmission characteristics of fundamental graphene plasmon mode in the proposed structure on frequency， geometric， material parameters， and chemical potential of graphene are investigated in detail by use of the finite element method. Simulation results show that the low refractive index SiO2 dielectric layer in the waveguide can achieve high-performance deep subwavelength light confinement. Thanks to the high refractive index contrast between the low refractive index SiO2 dielectric layer and the SOI substrate as well as the graphene layer， a low-loss plasmon mode with a very small mode field area is obtained. The proposed waveguide structure provides a certain reference for the design of high-performance and deep sub-wavelength tunable integrated photonic devices.