We theoreticallydemonstrate the realization of the ultranarrow dual-band perfect absorption at visible range in 3D metamaterials comprising Au vertical split-ring resonators (VSRRs) array above a thick Au film for high-sensitivity sensing. By placing the 3D metamaterial of Au VSRRs directly onto the Au substrate to remove the dielectric substrates effect, the simulated results reveal that ultranarrow dual-band perfect absorption with the two narrow absorption bandwidth of 7.3 nm and 1.1 nm in the visible regime can be excited from pure magnetic plasmon (MP) resonance and via the strong coupling between the MP resonance of the VSRRs and the surface plasmons polaritons (SPPs) propagating on the Au film, respectively. Moreover, coupling effects in the VSRRs with different structural parameters also are studied in detail. Because of the ultranarrow dual-band perfect absorption of the VSRRs being extremely sensitive to the changes of the material surrounding, our proposed 3D metamaterial exhibits ultrahigh sensitivity ( S = 918 nm/RIU, S ^* = 680/RIU) and figure of merit ( FoM = 835, FoM ^* = 4.5×10 ⁶ ) in near-infrared regime, which hold potential applications in label-free biosensing.

中文翻译：

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基于三维超材料的可见光和近红外区域超窄双波段完美吸收用于超高灵敏度传感

我们从理论上证明了在 3D 超材料中实现可见光范围内的超窄双波段完美吸收，该超材料包括用于高灵敏度传感的厚 Au 膜上方的 Au 垂直裂环谐振器 (VSRR) 阵列。通过将 Au VSRRs 的 3D 超材料直接放置在 Au 衬底上以消除介电衬底效应，模拟结果表明，在可见光区可以激发具有 7.3 nm 和 1.1 nm 两个窄吸收带宽的超窄双带完美吸收分别来自纯磁等离子体 (MP) 共振和通过 VSRR 的 MP 共振与在 Au 膜上传播的表面等离子体激元 (SPP) 之间的强耦合。此外，还详细研究了具有不同结构参数的 VSRR 中的耦合效应。 S = 918 纳米/RIU， S ^* = 680/RIU) 和品质因数 ( FoM = 835， FoM ^* = 4.5×10 ⁶ ) 在近红外范围内，在无标记生物传感中具有潜在的应用。