Zhang Weifeng, Chen Xianfeng, Ye Fangwei
Opt Lett. 2017 Oct 15;42(20):4063-4066. doi: 10.1364/OL.42.004063.
Photonic topological insulators are optical structures supporting robust propagation of light at their edges that are topologically protected from scattering. Here we propose the concept of plasmonic topological insulators (PTI) that not only topologically protect light at the lattice edges but also enable their confinement and guidance at the deep-subwavelength scale. The suggested PTI are composed of an evanescently coupled array of metallic nanowires that are modulated periodically along the light propagation direction. The intrinsic loss associated with the PTI is found not to deteriorate their topological protection on the edge modes. The proposed PTI may find interesting applications in nanophotonics, where the tolerance to the fabrication disorders for device applications are essential.
光子拓扑绝缘体是一种光学结构，能够支持光在其边缘稳健传播，且这种传播在拓扑上受到保护而免受散射影响。在此，我们提出了等离子体拓扑绝缘体（PTI）的概念，它不仅能在晶格边缘对光进行拓扑保护，还能在深亚波长尺度上实现光的限制与引导。所提出的PTI由沿光传播方向周期性调制的金属纳米线的倏逝耦合阵列组成。发现与PTI相关的固有损耗并不会削弱其对边缘模式的拓扑保护。所提出的PTI可能在纳米光子学中找到有趣的应用，在纳米光子学中，器件应用对制造缺陷的耐受性至关重要。
