Electrical and Computer Engineering Department, Boston University, Boston, Massachusetts 02215, United States.
Nano Lett. 2011 Sep 14;11(9):3694-700. doi: 10.1021/nl201677h. Epub 2011 Aug 1.
We experimentally demonstrate for the first time a very compact plasmonic hetero-oligomer structure where the multiple radiant and subradiant modes can be tailored independently. Unlike previous approaches based on collective excitations in complex plasmonic systems, we show precise engineering of resonances leading to simultaneous spectral overlap of multiple plasmonic modes with opposite radiative character. This asymmetric behavior combined with inherent spatial features of the structure leads to directional double Fano resonances as shown with numerical analysis. A model based on temporal coupled mode theory is also provided to describe the double Fano behavior.
我们首次实验证明了一种非常紧凑的等离子体杂化寡聚物结构，其中多个辐射和亚辐射模式可以独立地进行调整。与以前基于复杂等离子体系统中的集体激发的方法不同，我们展示了对共振的精确工程设计，从而导致具有相反辐射特性的多个等离子体模式的同时光谱重叠。这种不对称行为与结构的固有空间特征相结合，导致了如数值分析所示的方向型双福诺共振。还提供了基于时域耦合模理论的模型来描述双福诺行为。
