典型结构混合表面等离子体波导的传输特性研究

发布时间：2018-04-16 15:04

本文选题：表面等离子体波导 + 有限元方法　；参考：《安徽大学》2017年硕士论文

【摘要】：近年来,随着科学技术的不断进步,表面等离子体在光子学研究中被广泛应用,受到了许多领域研究者的关注。表面等离子体是一种电磁表面波,在表面处场强最强,能够被电子或者光子激发。表面等离子体激元的分布深度可小于波长量级,可用于亚波长量级的光电子集成器件的制作。但是表面等离子体激元传输时有较大损耗,在限制了其应用。表面等离子体激元能够实现纳米尺度的光信息传输与处理。表面等离子体激元的独特特性,使得它在高灵敏生物检测、传感和新型光源等领域获得了广泛的应用。本文利用表面等离子体激元的性质,对金属纳米线的光传输特性进行分析,内容如下:(1)对金属圆柱结构的表面等离子体波导的传输特性进行研究,分析了在固定波长1550nm下,波导几何参数和金属材料(Ag和Au)对传输特性的影响。结果表明,此波导结构的能流密度主要集中分布在金属柱的圆周处,且越靠近金属圆柱,其能流密度越大,银棒的传输特性更有优势。(2)接着对有基底的金属圆柱的表面等离子体波导的传输特性进行研究,通过改变金属圆柱的直径和圆柱与基底的距离,分析此波导沿纵向的能流密度、有效折射率、传播长度和模式面积。分析比较不同基底材料(硅和锗)的传输特性,得到锗基底结构更具有优势。(3)设计了一种高折射率材料为基底的金属双椭圆表面等离子体波导,利用有限元方法对这种波导支持的基模的能流密度分布、有效折射率、传播长度和有效面积与几何参数和结构的依赖关系进行了分析。从能流密度分布看出,能量主要集中分布在两个金属椭圆柱之间的中心区域,在金属与锗基底之间和基底与基底之间也都有能量存在。通过调节两个椭圆的中心距离和它们的两个半轴的大小,对此波导的传输特性的分析。(4)为了更进一步的研究表面等离子体波导,提出了一种新的波导结构,此结构是在金属环中嵌入两个介质块,通过调节间隙宽度和介质宽度来分析传输特性。该结构能够广泛应用于光子集成电路和传感器领域。总的来说,表面等离子体波导的传输特性可以通过改变几何参数、通信波长等来分析。本文主要研究在工作波长固定的条件下,不同结构的表面等离子体波导,通过调节几何结构的参数来分析其传输特性,如有效折射率、传播长度、模面积等性质,这些研究为未来光通信和光传感提供理论依据。
[Abstract]:In recent years, with the development of science and technology, surface plasma has been widely used in photonics, and has been paid attention to by many researchers.Surface plasma is an electromagnetic surface wave. It is the strongest field on the surface and can be excited by electrons or photons.The depth of surface plasmon distribution can be less than that of wavelength, which can be used to fabricate subwavelength optoelectronic integrated devices.However, the surface plasmon transmission has a large loss, which limits its application.Surface plasmon can transmit and process optical information at nanometer scale.Because of its unique characteristics, surface plasmon has been widely used in high sensitive biological detection, sensing and new light sources.In this paper, the optical propagation characteristics of metal nanowires are analyzed by using the properties of surface plasmon. The transmission characteristics of metal cylindrical surface plasmon waveguides are studied as follows. At fixed wavelength 1550nm, the propagation characteristics of surface plasmon waveguides are analyzed.The influence of waveguide geometry parameters and metal materials such as Ag and Au) on transmission characteristics.The results show that the energy flow density of the waveguide structure is mainly distributed in the circumference of the metal column, and the closer it is to the metal cylinder, the higher the energy flow density is.(2) the propagation characteristics of the surface plasma waveguide of a metal cylinder with a substrate are studied. By changing the diameter of the metal cylinder and the distance between the cylinder and the substrate, the longitudinal energy flow density of the waveguide is analyzed.Effective refractive index, propagation length and mode area.By analyzing and comparing the transport properties of different substrate materials (Si and GE), it is found that GE substrate structure has more advantages. A metal double ellipse surface plasma waveguide with high refractive index material is designed.The dependence of the energy flux density, the effective refractive index, the propagation length and the effective area on the geometric parameters and the structure of the fundamental modes supported by the waveguide is analyzed by using the finite element method.It can be seen from the energy flux density distribution that the energy is mainly distributed in the central region between the two metal elliptic columns and between the metal and germanium substrates as well as between the metal and germanium substrates.By adjusting the central distance of two ellipses and the size of their two half-axes, the propagation characteristics of this waveguide are analyzed. (4) in order to further study the surface plasma waveguide, a new waveguide structure is proposed.Two dielectric blocks are embedded in the metal ring and the transmission characteristics are analyzed by adjusting the width of the gap and the width of the medium.The structure can be widely used in the field of photonic integrated circuits and sensors.In general, the propagation characteristics of surface plasma waveguides can be analyzed by changing geometric parameters and communication wavelengths.In this paper, the propagation characteristics of surface plasma waveguides with different structures, such as effective refractive index, propagation length, mode area and so on, are analyzed by adjusting the geometric structure parameters under the condition of fixed working wavelength.These studies provide theoretical basis for future optical communication and optical sensing.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O485

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