利用FDTD对金属纳米颗粒的表面等离激元效应的模拟研究_毕业论文

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利用FDTD对金属纳米颗粒的表面等离激元效应的模拟研究

摘要:纳米光子学是研究在纳米尺度上光与物质相互作用的科学与技术。其在关于生物医学工具、信息存储、新型光学材料制备等方面发挥着不容忽视的作用。作为纳米光子学的代表——等离子体光学在生物,物理化学和医药等领域影响力极大。时域有限差分法(FDTD)是对电磁波进行仿真和模拟,目前已经在很多领域取得重大研究成果有着很大应用价值。本文主要采用时域有限差分(FiniteDifferenceTimeDomain,FDTD)仿真方法研究把不同波长的光照射到不同尺寸不同排列不同间隔不同形状的金属纳米颗粒表面后光的强度分布情况,通过对纳米颗粒表面的光强变化情况来分析其局域表面等离激元效应。本论文首先介绍了纳米光子学和金属纳米结构以及表面等离基元的概念和国内外的研究现状以及理论发展、应用前景。其次给出时域有限差分方法的概念、基本原理、算法特点和一些值得注意的问题最后通过FDTDSolutions仿真软件对金纳米颗粒的表面场强分布情况进行仿真模拟,分别对在相同的入射光照射下的1)不同尺寸的金纳米颗粒、2)不同间距、同一尺寸的金纳米颗粒、3)不同形状的金纳米颗粒金纳米颗粒的电磁特性以及同一尺寸的金纳米球颗粒在不同波长入射光的电磁特性进行了模拟仿真,并分析了金纳米颗粒的局域表面等离激元效应随着金纳米颗粒的尺寸、间距、形状以及入射光波长的变化而发生相应的变化。

通过对上述问题的讨论分析,我们对金属纳米颗粒的表面等离激元效应的一些性质有了较为深入的认识。同时了解了如何利用常用的数值模拟软件进行实际的运算,为更深入的研究打下了基础。

关键词:纳米光子学;时域有限差分法FDTD;表面等离激元;金属纳米颗粒

Abstract:Nanophotonics is photonic science and technology that utilizes light-matter interactions on the nanoscale. It plays an important role in biomedical tools, information storage, and the preparation of new optical materials. As a representative of nano photonics, plasma optics has a strong influence in the fields of biology, physics, chemistry and medicine. Time domain finite difference method (FDTD) is to simulate electromagnetic waves, which has been obtain significant research results in many areas .In this paper ,we used time domain finite difference simulation method to study the intensity distribution of light on the surface of metal nanoparticles when different wavelengths of light illuminate on the metal nanoparticles. Moreover, we also simulated the light intensity on the surface of metal nanoparticles with different sizes. The local surface plasmonic effect is analyzed through researching the change of light intensity on the surface of nanoparticles. In this paper, we made dissertation from the following aspects. Firstly, we introduced the concepts of nano photonics, metal nanostructures and surface plasmas, summarized the researchs’ status, the development of theoretical and the prospects of application in the  world. Secondly, the concept, basic principle, the characteristic of algorithm and some noteworthy problems of time - domain finite difference method are given. Finally, the field intensity distribution of gold nanoparticles was simulated by FDTD Solutions simulation software through changing the following parameters:1) the sizes of gold nanoparticles, 2) the spaces of gold nanoparticles,3) the shape of gold nanoparticles, these electromagnetic properties were simulated under the same incident light. And the electromagnetic properties of gold nanoparticles with the same size illuminated by different wavelengths light are simulated. Thereby,the local surface plasmon effect of gold nanoparticles is analyzed with the change of the size, space, shape and wavelength of the incident nanoparticles.

Through the discussion and analysis of the above problems, we have a more in-depth understanding of the properties on the surface plasmon of  metal nanoparticles. Moreover, we understand how to use the numerical simulation software to operation, and lay the foundation for further research. (责任编辑:qin)