Lee Chun-Ho, Seo Min-Kyo
Opt Lett. 2020 May 1;45(9):2502-2505. doi: 10.1364/OL.392540.
Hyperbolic metasurfaces have attracted much interest due to novel optical properties including self-focusing, diffraction-less propagation, and negative refraction. However, conventional hyperbolic metasurfaces employing transverse-magnetic-like (TM-like) guided modes operate limited to short wavelengths. Here, we propose a broadband hyperbolic metasurface utilizing the transverse-electric-like (TE-like) guided modes of silver nanowires. The symmetric TE-like mode of the nanowire metasurface supports strong near-field coupling through the metallic element for hyperbolicity from visible to near-infrared wavelengths. Using numerical simulations, we examine the modal and dispersion properties depending on the wavelength and geometry. Particularly, negative refraction at the interface between a hyperbolic metasurface and the normal-dispersion planar waveguide is also demonstrated.
双曲线超表面因其包括自聚焦、无衍射传播和负折射在内的新颖光学特性而备受关注。然而，采用类横向磁（TM 类）导模的传统双曲线超表面仅在短波长下工作。在此，我们提出一种利用银纳米线的类横向电（TE 类）导模的宽带双曲线超表面。纳米线超表面的对称 TE 类模式通过金属元素支持从可见光到近红外波长的双曲线性的强近场耦合。通过数值模拟，我们研究了取决于波长和几何形状的模式和色散特性。特别地，还展示了双曲线超表面与正常色散平面波导界面处的负折射。
