基于异质纳米结构表面等离子体Fano共振研究

发布时间：2018-05-03 10:04

本文选题：表面等离子体共振 + Fano共振　；参考：《华东师范大学》2015年硕士论文

【摘要】：作为一种新型的等离子体现象,Fano共振凭借其尖锐的光谱特征和极强的光场束缚能力在生物和化学探测领域具有潜在应用价值。虽然Fano共振在最近几年得到了广泛研究,但是关于异质纳米结构中由不同结构提供明暗模式相互耦合产生Fano共振的报道还比较少。本学位论文利用时域有限差分软件(FDTD)理论模拟了表面等离子体共振耦合的Fano效应,主要研究内容和创新点如下：(1)理论证明了A1-Ag纳米棒异质二聚体消光谱中产生的等离子体Fano共振是由短的A1纳米棒支持的偶极明模式和长的Ag纳米棒支持的四极暗模式相消耦合得到的。可以通过改变纳米棒尺寸、端面形状、间距和周围环境的介电常数调节Fano共振的共振波长和振幅。A1-Ag纳米棒异质二聚体对周围环境具有很高的灵敏性,FoM值为7.0。(2)理论证明了硅-金纳米腔散射光谱于近红外区出现的明显的非对称磁基Fano共振是由正交电磁模式直接相互作用产生的。不同于以前报道的关于金属纳米颗粒团簇中的磁基Fano共振,硅磁偶极共振提供的窄的离散模式可以直接被外部入射光源激发,而且在Fano dip处电磁近场增强可以同时达到最大。综上所述,通过对异质纳米结构中等离子体Fano共振产生机理和近场增强的研究,使Fano共振的调节更具可控性,为后续等离子体感应和探测等相关实验提供了理论依据。
[Abstract]:As a new type of plasma phenomenon, Fano resonance has a potential application value in biological and chemical detection fields with its sharp spectral characteristics and very strong optical field binding ability. Although Fano resonance has been widely studied in recent years, the interaction between different structures in heterogeneous nanostructures is coupled with different structures. There are few reports on the birth Fano resonance. This thesis uses the finite difference time domain (FDTD) theory to simulate the Fano effect of the surface plasmon resonance coupling. The main research contents and innovation points are as follows: (1) the theory proved that the plasma Fano resonance produced in the A1-Ag nanorod heterostructure of the heterostructure is composed of short A1 nanorods. The supported dipole mode and the long Ag nanorod supported quadrupole coupling are obtained. The resonant wavelength and amplitude of the Fano resonance can be adjusted by changing the size of the nanorods, the shape of the end, the distance and the permittivity of the surrounding environment. The heterostructure of the.A1-Ag nanorods is highly sensitive to the circumference environment, and the FoM value is 7.0. (2). It is proved that the apparent asymmetric magnetic base Fano resonance of the scattering spectra of silicon gold nano cavity in the near infrared region is produced by the direct interaction of the orthogonal electromagnetic mode. Different from the previous reports about the magnetic based Fano resonance in the metal nanoparticles cluster, the narrow discrete mode of the silicon magnetic dipole resonance can be directly externally inserted. The radiation source is excited and the electromagnetic near field enhancement at Fano dip can reach the maximum at the same time. In summary, the regulation of the Fano resonance is more controllable by the study of the generation mechanism of Fano resonance in the heterogeneous nanostructures and the near-field enhancement, which provides a theoretical basis for the related experiments of the subsequent plasma induction and detection.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;O657.3

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