Shi Jialing, Ju Lili, Zhang Xin, Huang Yingzhou, Fang Yurui
State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.
Chongqing Industry Polytechnic College, Chongqing 400044, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Feb 5;266:120465. doi: 10.1016/j.saa.2021.120465. Epub 2021 Oct 6.
Nanogaps are one of the most useful systems in nanooptics. The gap modes in a film coupled dielectric nanoparticle dimer system are influenced by both of the film and the electric and magnetic modes of the particles. In this work, strong confinement of gap modes of dielectric (Si) nanoparticle dimer on Au/Si film is investigated. The results show an abnormal electric field enhancement obtained between Si nanoparticle dimer on metal film, which is attributed to film coupled electric and magnetic dipole modes in dielectric nanoparticle dimer. The results are further analyzed with mode hybridization theory. Furthermore, the surface enhanced Raman spectroscopy (SERS) is performed to demonstrate these theoretical analyses. The film induced electromagnetic field redistribution in dielectric nanoparticle dimer not only extend the knowledge of dielectric gap modes but also has tremendous applications, e.g. light manipulating in subwavelength, light harvest, surface enhanced spectrum, etc.
纳米间隙是纳米光学中最有用的系统之一。薄膜耦合介电纳米颗粒二聚体系统中的间隙模式受薄膜以及颗粒的电和磁模式的影响。在这项工作中，研究了金/硅薄膜上介电（硅）纳米颗粒二聚体间隙模式的强限制。结果表明，在金属薄膜上的硅纳米颗粒二聚体之间获得了异常的电场增强，这归因于介电纳米颗粒二聚体中薄膜耦合的电偶极和磁偶极模式。利用模式杂交理论对结果进行了进一步分析。此外，进行了表面增强拉曼光谱（SERS）以证明这些理论分析。薄膜在介电纳米颗粒二聚体中引起的电磁场重新分布不仅扩展了介电间隙模式的知识，而且还有巨大的应用，例如亚波长光操纵、光捕获、表面增强光谱等。
