Fano Resonances Generated in a Single Dielectric Homogeneous Nanoparticle with High Structural Symmetry
Fano Resonances Generated in a Single Dielectric Homogeneous Nanoparticle with High Structural Symmetry
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具有高结构对称性的单一介电均质纳米粒子产生法诺共振
DOI：
10.1021/jp512003b
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发表时间：
2015-02-26
影响因子：
3.7
通讯作者：
Liu, Shao-Ding
中科院分区：
文献类型：
--
作者：
Cai, Dong-Jin;Huang, Yun-Huan;Liu, Shao-Ding
等离子体纳米结构中的Fano共振有效地抑制了辐射损耗，但非辐射欧姆损耗限制了许多重要应用的性能。此外，在具有高结构对称性的单个等离子体均匀纳米颗粒中很难产生强的Fano共振。介电纳米结构为上述问题提供了潜在的解决方案。在单个介电纳米颗粒中存在各种次辐射混合模式，使得产生Fano共振成为可能。该研究表明，由于亚辐射混合EH（12）d模式的激发，在单个硅纳米盘中产生了强烈的Fano共振。高阶次辐射混合模式（EH13 δ和EH14 δ）被激发通过操纵盘半径，和多个Fano共振出现在光谱中。这些光学响应不依赖于延迟效应，并且即使对于非常薄的盘也会产生强的Fano共振。在单个介电三角形、正方形或矩形纳米片中可以得到类似的结果。简单的几何形状和高度的结构对称性使这些介电纳米粒子在生物传感和光电子学中的实际应用前景广阔。
Fano resonances in plasmonic nanostructures suppress radiative losses effectively, but nonradiative Ohmic losses limit the performance of many important applications. In addition, it is hard to generate strong Fano resonances in a single plasmonic homogeneous nanoparticle with high structural symmetry. Dielectric nanostructures offer a potential solution to the above issues. There are various subradiant hybrid modes in a single dielectric nanoparticle, making it possible to generate Fano resonances. This study shows that due to the excitation of the subradiant hybrid EH(12)d mode a strong Fano resonance is generated in a single silicon nanodisk. Higher-order subradiant hybrid modes (EH13 delta and EH14 delta) are excited by manipulating the disk radius, and multiple Fano resonances arise in spectra. These optical responses are not dependent on a retardation effect, and strong Fano resonances are generated even for a very thin disk. One can get similar results in a single dielectric triangle, square, or rectangle nanoplate. The simple geometry and high structural symmetry make these dielectric nanoparticles promising for practical implementations in biosensing and optoelectronics.