Electromagnetic field hugely enhanced by coupling to optical energy focusing structure.
Electromagnetic field hugely enhanced by coupling to optical energy focusing structure.
复制标题
DOI：
10.1364/oe.25.007358
复制
发表时间：
2017-04
期刊：
影响因子：
3.8
通讯作者：
Wei Li;Yumin Hou
中科院分区：
文献类型：
--
作者：
Wei Li;Yumin Hou
在这篇文章中，我们介绍了一种新的光学能量聚焦结构组成的圆形介质布拉格纳米腔和圆形金属等离子体透镜。通过布拉格腔模式和表面等离子体模式的混合，在线偏振照明下，光能被高度限制在布拉格纳米腔的中心区域。当蝴蝶结纳米天线（BNA）或磁谐振器（MR）放置在这种聚焦结构上时，能量可以高效地耦合并聚焦到BNA或MR中。模拟表明，电场增强（|E|/|E0|）在BNA和磁场增强（|H|/|H0|）在MR中分别可以大于3000和200。这种混合电介质-金属结构为能量聚焦和转移开辟了一条新的途径，并为各种应用提供了机会，包括单分子Sers，光学捕获，光刻，荧光显微镜，磁传感器等。
In this article, we introduce a new optical energy focusing structure consisting of a circular dielectric Bragg nanocavity and a circular metallic plasmonic lens. Via the hybridization of Bragg cavity modes and surface plasmon modes, optical energy is highly confined in the central region of the Bragg nanocavity under linearly polarized illumination. When either a bowtie nano-antenna (BNA) or a magnetic resonator (MR) is placed on this focusing structure, the energy can be high-efficiently coupled and focused into the BNA or MR. Simulations show that the electric field enhancement (|E|/|E0|) in the BNA and magnetic field enhancement (|H|/|H0|) in the MR can be more than 3000 and 200, respectively. This proposed hybrid dielectric-metallic structure opens a new avenue in energy focusing and transferring and provides opportunities for various applications, including single-molecule SERS, optical trapping, photolithography, fluorescent microscopy, magnetic sensors, etc.