Excitation and tuning of Fano-like cavity plasmon resonances in dielectric-metal core-shell resonators
Excitation and tuning of Fano-like cavity plasmon resonances in dielectric-metal core-shell resonators
复制标题
介电金属核壳谐振器中类法诺腔等离子体共振的激发和调谐
DOI：
10.1039/c5nr09249c
复制
发表时间：
2016-01-01
期刊：
影响因子：
6.7
通讯作者：
Wang, Zhenlin
中科院分区：
文献类型：
--
作者：
Gu, Ping;Wan, Mingjie;Wang, Zhenlin
法诺共振已经在等离子体系统中实现，并且已经发现了有趣的应用，然而，在这些应用中，通常涉及精确控制的对称性破缺或多个组分的特定排列。虽然简单的核-壳型架构组成的一个球形的电介质核心和同心金属壳层已被提出作为良好的候选人，支持固有的Fano共振，这些理论预测很少看到任何详细的实验研究。在这里，我们报告了介电金属核壳谐振器中基于磁和电的多极等离子体Fano谐振的实验研究，该谐振器是通过在介电球体周围包裹近乎完美的金属壳层而形成的。我们证明，这些法诺共振起源于米氏腔和球等离子体共振之间的干涉。此外，我们提出，无论是电介质芯的大小或芯的折射率的变化允许很容易地调谐所观察到的Fano共振在很宽的光谱范围内。我们的研究结果与分析计算非常一致，为实现超灵敏生物传感器，激光和非线性光学器件提供了前所未有的机会。
Fano resonances have been realized in plasmonic systems and have found intriguing applications, in which, however, precisely controlled symmetry breaking or particular arrangement of multiple constituents is usually involved. Although simple core-shell type architectures composed of a spherical dielectric core and a concentric metallic shell layer have been proposed as good candidates that support inherent Fano resonances, these theoretical predictions have rarely seen any detailed experimental investigation. Here, we report on the experimental investigation of the magnetic and electric-based multipolar plasmonic Fano resonances in the dielectric-metal core-shell resonators that are formed by wrapping a nearly perfect metal shell layer around a dielectric sphere. We demonstrate that these Fano resonances originate from the interference between the Mie cavity and sphere plasmon resonances. Moreover, we present that the variation on either the dielectric core size or core refractive index allows for easily tuning the observed Fano resonances over a wide spectral range. Our findings are supported by excellent agreement with analytical calculations, and offer unprecedented opportunities for realizing ultrasensitive bio-sensors, lasing and nonlinear optical devices.