论文标题
通过模式拓扑转换在双曲线波导中介导的慢光
Slow light mediated by mode topological transitions in hyperbolic waveguides
论文作者
论文摘要
我们表明，由由II型双曲线材料组成的膜制成的对称平面波导，其中光轴（OA）平行于波导界面，从而导致分散图中的一系列拓扑跃迁，因为膜电厚度增加。这些过渡是由椭圆模式分支介导的，椭圆形分支，它们一旦从截止物生长出来，就会沿OA与异常有序的双曲模式分支结合，从而导致鞍点。当薄膜的电厚度进一步增加时，合并的分支开始向双曲线正常有序模式的过渡，其传播方向与OA正交。在此过程中，马鞍点被转变为一个分支点，在该分支点上出现了新的幽灵波，并且在各种厚度范围内观察到慢光。
We show that symmetric planar waveguides made of a film composed of a type II hyperbolic metamaterial, where the optical axis (OA) lays parallel to the waveguide interfaces, result in a series of topological transitions in the dispersion diagram as the film electrical thickness increases. The transitions are mediated by elliptical mode branches, which, as soon as they grow from cutoff, coalesce along the OA with anomalously ordered hyperbolic mode branches, resulting in a saddle point. When the electrical thickness of the film increases further, the merged branch starts a transition to hyperbolic normally ordered modes with propagation direction orthogonal to the OA. In this process, the saddle point is transformed into a branch point where a new branch of Ghost waves appears and slow light is observed for a broad range of thicknesses.
