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* = 4.5×106) 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，实现超高灵敏度传感


我们从理论上证明了 3D 超材料在可见光范围内实现超窄双波段完美吸收，该材料包括厚金薄膜上方的金垂直裂环谐振器 (VSRR) 阵列，用于高灵敏度传感。通过将Au VSRR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，可以激发可见光区域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 VSRR 的 MP 共振与在金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。由于VSRR的超窄双频完美吸收对周围材料的变化极其敏感，我们提出的3D超材料表现出超高的灵敏度（S = 918 nm/RIU，S* = 680/RIU）和品质因数（ FoM = 835，FoM* = 4.5×106）在近红外区域，在无标记生物传感中具有潜在的应用。