周期性结构的金属—介质纳米线电磁散射特性研究

发布时间：2018-01-26 06:42

本文关键词： 表面等离子体共振散射周期性光栅 Rayleigh异常　出处：《南京林业大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着纳米科学与纳米技术的快速发展,纳米器件与电磁波之间的相互作用得到广泛应用。纳米光子学一直是重要的研究课题,其纳米器件可广泛应用于光学传感器,光学成像以及集成器件等领域。有关纳米器件光学特性的相关文献研究非常宽泛,受器件的尺寸和激励光源的影响,对光学作用的研究方法也各不相同。本文将重点研究柱状纳米模型,通常被称为纳米柱或纳米线。本文应用柱面波展开和圆柱T矩阵研究了TE极化平面波激励下单根、两根金属-介质纳米线的散射特性。研究发现,如果选择合适的激励波长,在纳米线上金属层的内、外表面,可以观察到由于表面等离子体共振引起的独特的近场分布。为了全面理解纳米线之间的光相互作用,在近场研究的基础上,还分析了随着激励波长变化的纳米线的散射截面和吸收截面,且发现纳米线的散射截面和吸收截面因表面等离子体共振作用而增强。对于两根纳米线系统,当选择合适的圆心距时,在特定的激励波长下,可以观察到强烈的耦合作用。由于等离子体共振耦合,在相邻纳米线缝隙中间还存在着新的等离子体场模式,同时纳米线的散射截面也随之明显增加。在研究自由空间的纳米线周期性结构,有介质衬底的纯金属(银)和金属(银)涂层的纳米线周期性结构的光散射特性的研究中,本文采用基于递归算法和Lattice Sums矩阵算法的精确而严格的公式计算。经过计算发现三种类型的共振:由于金属纳米线本身引起的表面等离子体共振,由于周期性光栅结构本身特性造成的Rayleigh异常和由于光栅结构和介质衬底相互作用形成的共振。通过对平行于纳米线轴向的磁场进行数值计算分析,对金属纳米线分界面上形成的局域场、光栅结构形成的强烈的反射场和介质衬底表面的场增强效应进行更深的物理层面的分析。从技术层面上看,以上对光栅结构散射特性的分析都非常重要,这些特征未来将在设计和制造等离子体光学器件中得到更广泛地应用。
[Abstract]:With the rapid development of nanoscience and nanotechnology, the interaction between nano-devices and electromagnetic waves has been widely used. Nano-photonics has been an important research topic. The nanodevices can be widely used in optical sensors, optical imaging and integrated devices. The research on the optical properties of nanodevices is very extensive, which is influenced by the size of the devices and the excitation light source. The research methods of optical action are also different. In this paper, we will focus on the study of columnar nanomodels. In this paper, the scattering properties of te polarized plane wave excited ordered roots and two metal-dielectric nanowires are studied by using cylindrical wave expansion and cylindrical T matrix, which are commonly referred to as nanowires or nanowires. If the appropriate excitation wavelength is selected, the inner and outer surfaces of the metal layer on the nanowires are selected. The unique near-field distribution caused by surface plasmon resonance can be observed. In order to fully understand the optical interaction between nanowires, the near field study is based on the study. The scattering cross section and absorption cross section of nanowires varying with excitation wavelength are also analyzed, and it is found that the scattering cross sections and absorption cross sections of nanowires are enhanced by surface plasmon resonance. A strong coupling can be observed at a specific excitation wavelength when the center distance is appropriate. Due to the plasmon resonance coupling, there is a new plasma field mode in the middle of the adjacent nanowire gap. At the same time, the scattering cross section of nanowires increases obviously. The periodic structure of nanowires in free space is studied. Light scattering characteristics of nanowire periodic structures of pure metal (silver) and metal (silver) coatings with dielectric substrates are investigated. In this paper, exact and strict formulas based on recursive algorithm and Lattice Sums matrix algorithm are used. Three types of resonance are found by calculation:. Surface plasmon resonance caused by metal nanowires. The Rayleigh anomaly caused by the characteristic of the periodic grating structure and the resonance formed by the interaction between the grating structure and the dielectric substrate. Numerical analysis of the magnetic field parallel to the axial direction of the nanowires. . The local field formed on the metal nanowire interface, the strong reflection field formed by the grating structure and the field enhancement effect on the surface of the dielectric substrate are analyzed on a deeper physical level. The above analysis of the scattering characteristics of grating structures is very important. These characteristics will be widely used in the design and manufacture of plasma optical devices in the future.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN011;TB383.1

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