Liu Zhiguang, Liu Zhe, Li Jiafang, Li Wuxia, Li Junjie, Gu Changzhi, Li Zhi-Yuan
Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Collaborative Innovation Center of Quantum Matter, Beijing, 200092, China.
Sci Rep. 2016 Jun 14;6:27817. doi: 10.1038/srep27817.
We demonstrate a 3D conductive coupling mechanism for the efficient generation of prominent and robust Fano resonances in 3D metamaterials (MMs) formed by integrating vertical U-shape split-ring resonators (SRRs) or vertical rectangular plates along a planar metallic hole array with extraordinary optical transmission (EOT). In such a configuration, intensified vertical E-field is induced along the metallic holes and naturally excites the electric resonances of the vertical structures, which form non-radiative "dark" modes. These 3D conductive "dark" modes strongly interfere with the "bright" resonance mode of the EOT structure, generating significant Fano resonances with both prominent destructive and constructive interferences. The demonstrated 3D conductive coupling mechanism is highly universal in that both 3D MMs with vertical SRRs and vertical plates exhibit the same prominent Fano resonances despite their dramatic structural difference, which is conceptually different from conventional capacitive and inductive coupling mechanisms that degraded drastically upon small structural deviations.
我们展示了一种三维导电耦合机制，用于在由垂直U形裂环谐振器（SRR）或垂直矩形板沿着具有超常光学传输（EOT）的平面金属孔阵列集成而成的三维超材料（MM）中高效产生显著且稳健的法诺共振。在这种配置中，沿着金属孔会感应出增强的垂直电场，并自然地激发垂直结构的电共振，这些垂直结构形成非辐射的“暗”模式。这些三维导电“暗”模式与EOT结构的“亮”共振模式强烈干涉，通过显著的相消和相长干涉产生明显的法诺共振。所展示的三维导电耦合机制具有高度通用性，因为带有垂直SRR和垂直板的三维MM尽管结构差异巨大，但都表现出相同显著的法诺共振，这在概念上不同于传统的电容性和电感耦合机制，传统机制在结构有小偏差时会急剧退化。
