针对涂覆石墨烯层的圆形纳米线结构中模式场约束特性较差,以及难以与常用的线偏光源进行耦合,提出两种涂覆石墨烯层的双椭圆形纳米线等离激元波导,并采用有限元方法详细研究该结构中的石墨烯等离激元模式特性对几何参数和物理参数的依赖关系。仿真结果表明,双椭圆形纳米线的排列方向、纳米线间距、椭圆长短轴的比值和石墨烯化学势对等离激元模式传输性能有显著影响。所提的涂覆石墨烯层的双椭圆形纳米线结构能够实现长距离传输和亚波长约束,并在可调谐纳米光子器件和红外传感等领域具有潜在的应用价值。

Considering the poor mode-field confinement characteristics of graphene-coated circular nanowire structures and the difficulty of coupling them with commonly used linearly polarized light sources, two types of graphene-coated elliptical nanowire pairs are proposed in this work. Finite element modeling is used to study the dependence of the graphene plasmon mode characteristics on the geometric and physical parameters of the structures. Simulation results show that the arrangement direction of the double elliptical nanowires, distance between the nanowires, ratio of the long and short axes of the ellipse, and graphene chemical potential have a significant effect on the transmission performance of the plasmon mode. The proposed graphene-coated elliptical nanowire pairs can realize long-distance transmission and subwavelength confinement, and it has potential application value in the fields of tunable nanophotonic devices and infrared sensing.