光子晶体慢光效应及光传输特性研究

发布时间：2018-06-04 04:33

本文选题：慢光 + 表面波　；参考：《电子科技大学》2016年硕士论文

【摘要】：慢光不仅可加强光与物质间的相互作用,还能控制这种相互作用的光谱带宽,实现全光存储系统中的延迟和临时存储光功能。因此研究光子晶体慢光技术是非常有意义的。传统的实验室实现慢光所需的条件非常严格,使得很难将慢光效应应用到实际工程当中去。在光子晶体中实现慢光,不需要特殊的外部条件,一般实验室环境下就能进行。由于光子晶体是高色散结构,通过修改光子晶体的本构参数或者建立独特的结构,其性质可以改变慢波。本文是以破坏光子晶体的周期结构实现慢光效应作为研究对象,主要内容如下:1、介绍了关于光子晶体及慢光技术的背景知识及研究意义。并对相关技术的发展现状和需要解决的问题进行了总结。然后,对光子晶体的电磁特性和慢光效应进行分析,用图文说明其慢光产生的原理。并详细阐述与本文相关的、现有的研究方法。2、提出了一种新的基于表面布洛赫模式的表面光子晶体慢光结构。并利用Rsoft软件通过平面波展开法对其表面的色散模式进行分析。对缺陷导模色散曲线平坦部分的分析可揭露表面缺陷光子光子晶体结构的慢光性质。设计平坦的缺陷导模色散曲线,获得更低群速度色散慢光属性。用有限元法分析得到有效的慢光现象,用COMSOL Multiphysics仿真软件在时域内得到了验证。3、针对线缺陷波导提出了两种线缺陷结构,即减小中间一排介质柱半径和删除中间一排介质柱中的部分。使用平面波展开法,通过改变介质柱的半径,可得正方形晶格光子晶体半径为0.20a时,其周期结构的最大光子带隙。然后对光在两种正方形晶格光子晶体线缺陷波导中的传输进行数值分析,以缺陷介质柱半径作为变量进行仿真分析,选取波导的最佳结构。用有限元法,在COMSOL Multiphysics的频域和时域中分别模拟光在两种结构中的传输特性。得到平面波在结构一和结构二波导中的传输群速分别为0.25c和0.172c,结果均与使用平面波展开法中的数值结论吻合。
[Abstract]:Slow light can not only enhance the interaction between light and matter, but also control the spectral bandwidth of the interaction, and realize the delay and temporary storage function in all-optical storage system. So it is very meaningful to study the slow light technology of photonic crystal. It is very difficult to apply the slow light effect to practical projects because of the strict conditions required by traditional laboratories to realize slow light. The realization of slow light in photonic crystals does not require special external conditions and can be carried out in general laboratory environments. Since photonic crystals are highly dispersive, slow waves can be changed by modifying the constitutive parameters of photonic crystals or establishing unique structures. The aim of this paper is to realize slow light effect by destroying the periodic structure of photonic crystals. The main contents are as follows: 1. The background knowledge and significance of photonic crystals and slow light technology are introduced. The status quo of related technologies and the problems that need to be solved are summarized. Then, the electromagnetic characteristics and slow light effect of photonic crystal are analyzed, and the principle of slow light generation is illustrated. A new surface photonic crystal slow light structure based on surface Bloch mode is proposed. The dispersion mode of the surface is analyzed by the plane wave expansion method using Rsoft software. The analysis of the flat part of the dispersion curve of the defect can reveal the slow light properties of the photonic crystal structure with surface defects. A flat defect guided mode dispersion curve is designed to obtain lower group velocity dispersion slow light properties. The effective slow light phenomenon is obtained by finite element method, and verified by COMSOL Multiphysics software in time domain. Two kinds of linear defect structures are proposed for the waveguide with linear defects. That is, reducing the radius of the middle row of the medium column and removing the part from the middle row of the medium column. By changing the radius of the dielectric column, the maximum photonic band gap of the periodic structure can be obtained when the radius of the square lattice photonic crystal is 0.20a by using the plane wave expansion method. Then the propagation of light in two square lattice photonic crystal waveguides with linear defects is analyzed numerically. The radius of the defect dielectric cylinder is taken as the variable to simulate and analyze, and the optimal structure of the waveguide is selected. The finite element method is used to simulate the propagation characteristics of light in COMSOL Multiphysics in frequency domain and time domain respectively. The group velocities of plane waves in structure-one and structure-two waveguides are 0.25c and 0.172c, respectively. The results are in good agreement with the numerical results obtained by using the plane wave expansion method.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O734

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