Teng Da, Wang Kai, Li Zhe, Zhao Yongzhe
Opt Express. 2019 Apr 29;27(9):12458-12469. doi: 10.1364/OE.27.012458.
In this paper, we show that the graphene-coated nanowire dimers could enable outstanding waveguiding performance in the mid-infrared range. The propagating properties of the fundamental graphene plasmon mode and their dependence on the nanowire radius, gap distance, nanowire permittivity and chemical potential of graphene are revealed in detail and compared with the graphene-coated circular nanowire. By improving the geometric parameters and the surface conductivity of graphene, the propagation length could reach about 9 μm, which is larger than that of the graphene-coated circular nanowire plasmon mode. Meanwhile, the effective mode area is only 10A, which is one order of magnitude smaller than that of the graphene-coated circular nanowire plasmon mode. Theoretically, the propagation length could be further enhanced by increasing the chemical potential. Besides, the proposed graphene-coated nanowire dimers show quite good fabrication tolerance. The manipulation of mid-infrared waves at the deep subwavelength scale using graphene plasmons may offer potential applications in tunable integrated nanophotonic devices and infrared sensing.
在本文中，我们表明石墨烯包覆的纳米线二聚体能够在中红外波段实现出色的波导性能。详细揭示了基本石墨烯等离子体激元模式的传播特性及其对纳米线半径、间隙距离、纳米线介电常数和石墨烯化学势的依赖性，并与石墨烯包覆的圆形纳米线进行了比较。通过改善石墨烯的几何参数和表面电导率，传播长度可达约9μm，大于石墨烯包覆的圆形纳米线等离子体激元模式的传播长度。同时，有效模式面积仅为10A，比石墨烯包覆的圆形纳米线等离子体激元模式小一个数量级。理论上，通过增加化学势，传播长度可以进一步提高。此外，所提出的石墨烯包覆的纳米线二聚体表现出相当好的制造容差。利用石墨烯等离子体激元在深亚波长尺度上对中红外波进行操控，可能在可调谐集成纳米光子器件和红外传感方面提供潜在应用。
