提出一种基于硅衬底的涂覆石墨烯层的三角形纳米线等离激元波导,并采用有限元方法详细研究了基模传输特性及其与几何参数、物理参数的关系。结果表明:间隙区域大小、顶角角度、圆角半径和石墨烯化学势对模式传输特性有很大影响。通过优化设计,该波导结构可以实现石墨烯等离激元的深度亚波长传输,传播距离可达10 μm,同时归一化模式场面积仅约为10 ^-6。该石墨烯表面等离激元波导为可调谐纳米光子器件的设计提供了一定的参考。

This paper proposes a plasmonic waveguide with a triangular-shaped graphene-coated nanowire integrated on the silicon substrate. The transmission properties of the fundamental graphene plasmon mode and their dependence on the geometric and physical parameters are fully investigated by the finite element method. The results show that the gap distance, vertex angle, corner radius, and chemical potential of graphene have significant influences on the modal transmission properties. By optimizing the design, the proposed structure can be used to achieve the deep-subwavelength modal field transmission with a propagation length of up to 10 μm and a normalized mode area of only about 10 ^-6. The proposed graphene plasmonic waveguide may offer a certain theoretical basis for the design of tunable nanophotonic devices.