The effect of nanorod position on the plasmonic properties of the complex nanorod in nanohole arrays
The effect of nanorod position on the plasmonic properties of the complex nanorod in nanohole arrays
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DOI：
10.1088/1361-6463/abd80f
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发表时间：
2021-04-15
影响因子：
3.4
通讯作者：
Zhao, Yiping
中科院分区：
文献类型：
--
作者：
Wang, Yanfeng;Zhang, Zhengjun;Zhao, Yiping
通过将纳米棒(NR)从中心移动到纳米孔(NH)的边缘，即打破几何对称性，可以在保持结构单元的高透过率和总尺寸的同时，将由NR和NH的局域表面等离子体共振的偶极耦合引起的特殊光学透过率(EOT)指数地调谐到红移。这种共振波长移动强烈地依赖于NR的移动方向，即它是沿着棒的长轴还是短轴移动的。将NR连接到NH，并增加晶格周期可以显著红移EOT模式，从而允许在中红外(MIR)区域实现超高透过率。这种结构具有高的局部电场、增强的传播波和可调的可见光-MIR共振波长，使其适合于从可见光到MIR波长范围内的紧凑和集成光学器件的设计。此外，由于不同等离子体模的耦合和杂化，产生了Fano共振，使得这种结构有利于高灵敏度的测量。
By moving the nanorod (NR) from the middle toward the rim of the nanohole (NH), i.e. breaking the geometric symmetry, the extraordinary optical transmission (EOT) caused by the dipole coupling of the localized surface plasmon resonance of the NR and the NH can be tuned to redshift exponentially while maintaining the high transmission and overall dimension of the structural unit. This resonant wavelength shift depends strongly on the moving direction of the NR, i.e. whether it is along the long axis or short axis of the rod. Connecting the NR to the NH and increasing the lattice period can significantly redshift the EOT mode, allowing ultra-high transmission in the mid-infrared (MIR) region. The high local E-fields, enhanced propagating waves with a tunable visible-MIR resonance wavelength, make this structure suitable for the design of compact and integrated optical devices from the visible to the MIR wavelength range. In addition, Fano resonances are emerging due to the coupling and hybridization of different plasmonic modes, making the structure beneficial for high sensitivity measurement.