High-efficiency chirality-modulated spoof surface plasmon meta-coupler.
High-efficiency chirality-modulated spoof surface plasmon meta-coupler.
复制标题
高效手性调制欺骗表面等离子体元耦合器
DOI：
10.1038/s41598-017-01664-w
复制
发表时间：
2017-05-02
影响因子：
4.6
通讯作者：
Sun S
中科院分区：
文献类型：
--
作者：
Duan J;Guo H;Dong S;Cai T;Luo W;Liang Z;He Q;Zhou L;Sun S
高效激发表面等离子体激元(SPP)在许多光子学应用中是非常必要的，但大多数方法(如棱镜和光栅耦合器)不能灵活地控制其SPP的激发方向。尽管最近提出了Pancharatnam-Berry(PB)亚表面来实现方向可控的SPP激发，但由于耦合器表面的直接反射以及耦合器与导出型等离子体结构之间的模式失配，这种方案存在效率低下的问题。在本文中，我们通过引入两个准则来指导超表面和等离子体金属的设计来解决这些问题，在此基础上可以实现非常高效率的方向可控的SPP激发。作为概念验证，我们设计并制作了一种工作在微波区的实际器件，并进行了近场和远场测量，结果表明该器件的SPP转换效率可达78%，远远高于以往的器件。全波模拟结果与实验结果吻合较好，优化设计后效率可进一步提高到92%。我们的发现可以刺激与SPP相关的欺骗应用，特别是有助于增强低频下依赖于自旋的光-物质相互作用。
Efficiently exciting surface plasmon polaritons (SPP) is highly desired in many photonic applications, but most approaches (such as prism and grating couplers) cannot control flexibly their SPP excitation directions. While Pancharatnam-Berry (PB) metasurfaces were recently proposed to achieve direction-controllable SPP excitations, such scheme suffers from low-efficiency issue due to both direct reflections at the coupler surface and the mode mismatch between the coupler and the guiding-out plasmonic structure. In this article, we solve these issues via imposing two criterions to guide design both the metasurface and the plasmonic metal, based on which a direction-controllable SPP excitation with very high efficiency can be realized. As a proof of concept, we designed/fabricated a realistic device working in the microwave regime, and performed both near-field and far-field measurements to demonstrate that it can achieve an spoof SPP conversion efficiency ~78%, much higher than previous devices. Full-wave simulations are in good agreement with experiments, showing that the efficiency can be further pushed to 92% with optimized designs. Our findings can stimulate spoof SPP-related applications, particularly can help enhance the spin-dependent light-matter interactions in low frequency regime.