光子学报, 2020, 49 (9): 0926001, 网络出版: 2020-12-26
基于单劈裂环-双劈裂盘结构的多重磁Fano共振 下载: 665次
Multiple Magnetic Fano Resonances Based on Single-split Ring and Double-split Disk Structure
表面等离激元 有限元分析 高阶磁模式 多重磁Fano共振 折射率灵敏度 Surface plasmons Finite element method High order magnetic modes Multiple magnetic Fano resonances Refractive index sensitivity
摘要
采用有限元方法对单劈裂环-双劈裂盘纳米结构的表面等离激元共振进行了理论研究.当入射光垂直于结构表面时,亮磁模式和暗磁模式相互干涉会产生磁Fano共振.当双劈裂盘、空腔和单劈裂环的间隙同时沿x轴负方向偏移时,可产生高阶磁模式和双重磁Fano共振.在此结构的基础上,进一步调节单劈裂环的间隙宽度,可以在近红外区域增强磁模式的强度,并产生三重磁Fano共振;同样地,通过调节双劈裂盘的上劈裂角,在可见光区域可得到新的高阶磁模式,并产生三重磁Fano共振.此外,该结构的最大灵敏度和磁场增强分别达到1 400 nm/RIU和69.7倍.这些光学特性使得该结构在超灵敏度生物传感器和多控磁Fano开关领域具有潜在的应用价值.
Abstract
The surface plasmon resonances of a nanostructure composed of a single-split ring and a double-split disk is studied theoretically by the finite element method. When the incident light is normal to the structure surface, a magnetic Fano resonance can be generated by the interference between a bright magnetic mode and a dark magnetic mode. High order magnetic modes and double magnetic Fano resonances can be generated when the double-split disk, the cavity, and the gap of the single-split ring offset together along the negative x-axis. On the basis of this structure, further modulating the gap width of the single-split ring, magnetic modes intensity is enhanced in the near-infrared region and triple magnetic Fano resonances is generated; similarly, by modulating the upper split angle of the double-split disk, high-order magnetic mode is obtained in the visible region and triple magnetic Fano resonances is generated. In addition, the maximum sensitivity and magnetic field enhancement of the structure can reach 1 400 nm/RIU and 69.7, respectively. These optical properties make the structure has potential application value in the field of ultra-sensitive biosensor and multi-control magnetic Fano switch.
牛启强, 霍义萍, 姜雪莹, 周辰, 郭懿圆, 侯艺博, 何倩, 郝祥祥. 基于单劈裂环-双劈裂盘结构的多重磁Fano共振[J]. 光子学报, 2020, 49(9): 0926001. Qi-qiang NIU, Yi-ping HUO, Xue-ying JIANG, Chen ZHOU, Yi-yuan GUO, Yi-bo HOU, Qian HE, Xiang-xiang HAO. Multiple Magnetic Fano Resonances Based on Single-split Ring and Double-split Disk Structure[J]. ACTA PHOTONICA SINICA, 2020, 49(9): 0926001.