Controlling optical field enhancement of a nanoring dimer for plasmon-based applications
Controlling optical field enhancement of a nanoring dimer for plasmon-based applications
复制标题
控制纳米环二聚体的光场增强，用于基于等离子体的应用
DOI：
10.1088/2040-8978/18/5/055007
复制
发表时间：
2016
影响因子：
2.1
通讯作者：
Jingquan Lin
中科院分区：
文献类型：
--
作者：
Alemayehu Nana Koya;Boyu Ji;Zuoqiang Hao;Jingquan Lin
在需要固定馈电间隙的实际应用中，控制耦合纳米结构的共振动力学和间隙等离子体振子超出常用参数（例如二聚体间隙）具有至关重要的意义。在这份报告中，我们显示控制的共振峰位移和间隙等离子体激元强度的紧密间隔的纳米环二聚体通过偏振和入射光的照射角，几何形状的组成纳米环和折射率的基板下面。对于固定的外半径和恒定的二聚体间隙，纳米二聚体的共振峰显示普遍红移的纳米环的内半径增加和入射光的偏振接近二聚体轴。此外，我们发现，增加内二聚体半径和引入一个小的分裂间隙的纳米二聚体的结果在高度增强的间隙等离子体激元强度。最后，在优化的二聚体几何形状和入射光的照射下，获得了纳米二聚体的682 nm RIU − 1折射率灵敏度，并详细讨论了其对基于表面的传感的影响。
Control of resonance dynamics and gap plasmons of coupled nanostructures beyond commonly used parameters such as the dimer gap has a paramount importance in practical applications where a fixed feed-gap is needed. In this report, we show control of resonance peak shift and gap plasmon intensity of a closely spaced nanoring dimer through polarization and illumination angle of incident light, geometry of the constituent nanorings and refractive index of the substrate underneath. For fixed outer radii and constant dimer gap, the resonance peak of the nanodimer shows universal redshift as the inner radii of nanorings increase and polarization of the incident light approaches the dimer axis. Furthermore, we show that increasing inner dimer radii and introducing a small split gap to the nanodimer results in highly enhanced gap plasmon intensity. Finally, at optimized dimer geometry and illumination of the incident light, 682 nm RIU−1 refractive index sensitivity of the nanodimer was obtained and its implication for surface-based sensing is discussed in detail.