Excitation of Multiple Fano Resonances in Plasmonic Clusters with D2h Point Group Symmetry
Excitation of Multiple Fano Resonances in Plasmonic Clusters with D2h Point Group Symmetry
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DOI：
10.1021/jp404575v
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发表时间：
2013-07-11
影响因子：
3.7
通讯作者：
Wang, Yun-Cai
中科院分区：
文献类型：
--
作者：
Liu, Shao-Ding;Yang, Yi-Biao;Wang, Yun-Cai
等离子体纳米结构中的Fano共振表现出尖锐的共振和强的光限制。这些性质对于依赖于等离子体线形状工程的传感应用是非常有用的。等离子体团簇中的Fano共振依赖于结构对称性，本研究提供了对具有D-2 h对称性的团簇中Fano共振的一般理解。结果表明，由于B-3u和B-2u暗次辐射模的激发，D-2 h对称性六聚体的光谱中出现了四种Fano共振。当引入一个中心粒子形成一个七聚体，它示出，除了对共振行为的影响或外观的额外的Fano共振对于一个特定的偏振，几个杂交暗子辐射模式被激发的两个偏振，和多达8种Fano共振出现在光谱中。具有D-2 h对称性的等离子体团簇适合于等离子体线成形，并且预期这些结构可用于多波长传感应用。这项研究还表明，团簇对称性工程是产生多重法诺共振和调谐光谱特征的有利方法。对于具有其他对称性的团簇也得到了类似的结果。
Fano resonances in plasmonic nanostructures exhibit sharp resonance and strong light confinement. These properties are very useful for sensing applications, which rely on plasmon line shape engineering. Fano resonances in plasmonic clusters depend on structure symmetry, and this study provides a general understanding of Fano resonances in clusters with D-2h symmetry. We show that, because of the excitation of B-3u and B-2u dark subradiant modes, four kinds of Fano resonances appear in the spectra for hexamers with D-2h symmetry. When a central particle is introduced to form a heptamer, it is shown that, aside from influence on the resonant behaviors or appearance of an additional Fano resonance for a specific polarization, several hybridized dark subradiant modes are excited for both polarizations, and up to eight kinds of Fano resonances appear in the spectra. Plasmonic clusters with D-2h symmetry are suitable for plasmon line shaping, and it is expected that these structures are useful for multiwavelength sensing applications. This study also reveals that cluster symmetry engineering is a favorable method for generating multiple Fano resonances and tuning spectral features. A similar result is obtained for clusters with other symmetries.