表面等离激元诱导的金属纳米宽单频带和窄多频带光透明特征研究

发布时间：2018-05-30 06:50

本文选题：局域表面等离激元 + 纳米结构　；参考：《江西师范大学》2015年硕士论文

【摘要】：21世纪新叶,亚波长表面等离激元学这门新兴学科掀起了等离激元纳米结构材料领域的研究热潮。相较传统光学设备,等离激元纳米结构材料具有体积小、适合集成、能突破光学衍射极限等优点,在太阳能,传感器,滤波器以及光耦合器等领域上有着巨大应用前景。本文从等离激元定义的介绍出发,以表面等离激元共振理论为基础,剖析等离激元纳米结构的奇特光学特性的内在物理机制,并基于有限时域差分法,设计了纳米微孔结构、双层金属纳米结构以及金属-介质-金属多层颗粒金属纳米结构这三种不同类型的新型纳米结构。通过结合局域等离激元和表面等离极化激元的相关理论,以透反射、电场强度分布特性等为载体,研究了各个纳米结构的新奇光学现象,得到了宽单频带或窄多频带的光透特性及其与结构参数间的关联作用,深入解析了金属纳米结构中各等离激元共振模式的物理机理。在第二章中,我们设计了一种在紫外光到红外光波段具有超完美、宽频带的光透射特性的新型金属纳米立方孔结,通过调节该金属纳米结构中立方孔的边长、间距以及填充介质等多个参数,从而获得了在紫外到红外波段高达99%的宽频带超完美光透射。该结构在新型金属透明电极、太阳能电池等领域具有很好的应用前景。在第三章中,我们设计了一种由六角周期排列的纳米立方体和立方孔组成的双层纳米结构。由于纳米孔与纳米立方体的强烈等离激元耦合作用,这种双层结构在可见及红外光波段出现了窄双频带高光透射。两个共振模的透射值均大于80%。双窄频带可以通过改变结构中纳米孔和纳米立方体的边长、周期和高度来有效调节。通过结合对应等离激元共振模式的电磁场能量分布模型,我们进一步分析了该结构中各透射频带的内在物理机制。这种局域窄双频带的复合等离激元纳米结构,可以广泛应用于光学滤波器和传感领域。在第四章中,我们设计了一种由金属-介质-金属同心圆柱体的纳米立方体颗粒阵列和金属薄层组成的新型结构。该结构在可见光及红外光范围内展现出了三个具有高光透射率的透射频带来自纳米颗粒的局域表面等离激元,底下金属层的表面等离极化激元的激发,以及他们的相互耦合作用。窄三频带光学特性可以通过内外圆柱体的半径,纳米颗粒的排列周期,银层的厚度以及内外层圆柱体间介质层的介电常数有效调节。从而有助于多频带光滤波器及复用型传感的研究。在第五章中,我们设计一种沉积于银层上的多层纳米圆盘结构。这种结构有六角周期排列的三层的金属-介质-金属垂直排列的纳米圆盘颗粒与银薄层组成。在其光谱图上共有三个等离激元膜产生,并分别是有等离激元明膜、暗膜以及法诺共振引起的。其中,明膜是由于偶极态膜对间的对称耦合,使其在光谱上产生宽频带。而暗膜则由于偶极矩限制无法在尺寸小的纳米结构中直接受入射光激发获得,故只能通过等离激元杂化理论中纳米圆盘间的非对称耦合大大减少结构的偶极矩,从而获得暗膜。由于纳米圆盘颗粒对中一个圆盘颗粒的位置、尺寸的变化导致结构对称性的破坏,导致高级态的暗膜耦合明膜,最终导致法诺共振现象。另外,底层金属银薄层的表面等离极化激元通过与纳米圆盘颗粒的局域表面等离激元的耦合作用对这三个等离激元膜都发挥着重大作用。就结果而言,这种纳米结构随着各圆盘层厚度、底下银层厚度以及中间层介电常数的变化具有良好的可调性。尤其是暗膜与法诺共振在光谱上有快速衰减窄频带宽,使其在光学传感器以及滤波器等领域有这巨大优势。
[Abstract]:In the new year of twenty-first Century, subwavelength surface plasmons and plasmons set off a hot research upsurge in the field of plasmon nanomaterials. Compared with traditional optical devices, plasmon nanomaterials are small in size, suitable for integration, and can break through the advantages of optical diffraction limit, such as solar energy, sensors, filters, and optical couplers. On the basis of the theory of surface plasmon resonance, the intrinsic physical mechanism of the peculiar optical properties of the nanoscale nanostructures, such as the surface plasmon resonance theory, is analyzed, and the nano microporous structure, the double layer metal nanostructure and the metal medium gold are designed on the basis of the surface plasmon resonance theory. It is a new type of nanostructure of three different types of granular metal nanostructures. By combining the related theory of local plasmons and surface plasmon polaritons, the novel optical phenomena of each nanostructure are studied by means of reflection and electric field intensity distribution, and the optical permeability characteristics of a wide single band or narrow multiband are obtained. In the second chapter, we designed a new type of nanometers cubic pore junction with ultra perfect and broadband light transmission characteristics in the ultraviolet to infrared light band, by adjusting the metal nanostructure in the metal nanostructure. In the third chapter, we have designed a kind of nanoscale vertical array of six angles in the third chapter. The structure has a good application prospect in the fields of new metal transparent electrode and solar cell. In the third chapter, we have designed a kind of nanoscale vertical array of six angles. The bilayer nanostructures consisting of a cube and a cubic hole. Due to the strong coupling of nanoscale and nano cubes, this double layer structure has a narrow double band high light transmission in visible and infrared wavelengths. The transmission values of the two resonant modes are all larger than the 80%. double narrow band, which can pass through the change of nanoscale and nano cubes in the structure. The internal physical mechanism of the transmission bands in the structure is further analyzed by combining the electromagnetic field energy distribution model with the corresponding plasmon resonance mode. This local narrow double frequency band composite plasmon nanostructure can be widely used in optical filters and sensing fields. In the fourth chapter, we have designed a new structure consisting of a metal dielectric metal concentric cylindrical nano cube particle array and a thin metal thin layer. This structure shows three transmittance bands with high transmittance in the visible light and infrared light range, the local surface plasmon from nanoscale particles, the bottom metal layer. The optical properties of the narrow tri band can be effectively regulated by the radius of the internal and external cylinders, the permutation period of the nanoparticles, the thickness of the silver layer and the dielectric constant of the dielectric layer between the inner and outer cylinders, which can help the research of the multiband optical filter and the multiplexing sensor. In the fifth chapter, we design a multilayer nanoscale disk deposited on the silver layer. This structure consists of three layers of metal - metal - metal - metal vertically arranged nanoscale disk particles and silver thin layers in a six corner periodic arrangement. There are a total of three plasmons produced on its spectrogram, and are respectively the plasmons, dark films, and the films. It is caused by the Fano resonance, which is due to the symmetrical coupling between the dipolar membrane and the broad band in the spectrum, while the dark film can not be directly excited by the incident light in small size nanostructures due to the dipole moment restriction, so it can only be greatly reduced by the asymmetric coupling between the nanoscale disks in the isopa hybrid theory. With the dipole moment of the structure, the dark film is obtained. Due to the change of the size of the particle size of the medium disk particles in the nanoscale disk, the symmetry of the structure is destroyed, which leads to the dark film coupling clear film in the advanced state, which eventually leads to the phenomenon of the Fano resonance. In addition, the surface of the surface of the thin layer of the silver layer of the underlying metal passes through the bureaus of the nanoscale disk particles. The coupling effect of the field surface and other excitations plays an important role in the three plasmons. As a result, the nanostructure has a good adjustable with the thickness of the disc layer, the thickness of the silver layer and the dielectric constant of the middle layer, especially the narrow band attenuation bandwidth of the dark film and the Fano resonance in the spectrum. It has great advantages in optical sensors and filters.
【学位授予单位】：江西师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O53;TB383.1

【共引文献】