Exceptional Points and Asymmetric Mode Switching in Plasmonic Waveguides
Exceptional Points and Asymmetric Mode Switching in Plasmonic Waveguides
复制标题
等离激元波导中的特殊点和非对称模式切换
DOI：
10.1109/jlt.2016.2609899
复制
发表时间：
2016-11-15
影响因子：
4.7
通讯作者：
Lu, Peixiang
中科院分区：
文献类型：
--
作者：
Ke, Shaolin;Wang, Bing;Lu, Peixiang
我们研究了由一对具有不同损耗的石墨烯片组成的非厄米特系统中的例外点。在石墨烯波导中存在两种表面等离子体激元模式。通过改变两个石墨烯片之间的距离和石墨烯的化学势，EP表现为本征值，即两个模式的波矢量合并。在由石墨烯的几何参数和化学势组成的参量空间中，将EP包围起来，可以观察到本征模的交叉转换和几何相位的变化。同时，某一输入SPP模式可能导致完全不同的输出。该研究为纳米级灵敏光开关和传感器的开发奠定了基础。
We investigate the exceptional points (EPs) in a non-Hermitian system composed of a pair of graphene sheets with different losses. There are two surface plasmon polaritons (SPPs) modes in the graphene waveguide. By varying the distance between two graphene sheets and chemical potential of graphene, the EPs appear as the eigenvalues, that is, the wave vectors of the two modes coalesce. The cross conversion of eigenmodes and variation of geometric phase can be observed by encircling the EP in the parametric space formed by the geometric parameters and chemical potential of graphene. At the same time, a certain input SPP mode may lead to completely different output. The study paves a way to the development of nanoscale sensitive optical switches and sensors.