基于直接激励暗模式的高品质因数太赫兹滤波器的设计与实现毕业论文
2021-11-04 20:59:09
摘 要
电磁诱导透明效应(electromagnetically induced transparency, EIT)原本是一种量子物理现象。在多能级原子系统中,通过量子干涉相消效应使原本不透明的介质对特定频率的入射电磁波呈现透明。随着超材料学科的发展,这种原本在量子物理领域实现条件非常苛刻的现象可以被超材料方便的模拟实现。这在慢光器件、传感器等器件的设计和制作方面有着重要的应用价值。因此用超材料实现电磁诱导透明效应引起了学者们的广泛研究,但是绝大部分的学者都是基于明模式与暗模式之间进行耦合的方法在超材料中实现电磁诱导透明效应。他们把研究重点放在了对明暗模式结构的设计上,不断地提出新的明模式与暗模式的结构,从而提高用超材料实现电磁诱导透明效应的应用价值。但是通过明暗模式之间耦合实现电磁诱导透明效应,对于明暗模式之间的相对位置有着严格的要求,稍有偏差就会导致实验的失败。若想要实际制造出此类超材料结构,对制造精度的要求有着较为苛刻的要求。
基于上述背景和意义,本文提出了一种新的基于超材料实现电磁诱导透明效应的方式。不再运用明模式和暗模式之间的耦合实现电磁诱导透明效应,而是通过直接激发超材料结构中在垂直入射下不能被激发的暗模式,从而实现电磁诱导透明效应。本文首先介绍了直接激发暗模式的理论基础,其次基于理论提出了可以被直接激发暗模式的超材料结构并用CST微波工作室进行仿真,最后基于电磁诱导透明效应得到了中心频率为0.471THz、品质因数为47.1的直接激发暗模式的高品质因数太赫兹滤波器。
关键词:太赫兹;超材料;暗模式;电磁诱导透明;滤波器
Abstract
Electromagnetic induced transparency (EIT) is originally a quantum physical phenomenon. In a multilevel atomic system, the original opaque medium is transparent by the quantum interference cancellation effect. With the development of the subject of metamaterials, this phenomenon, which was originally implemented in the field of quantum physics, can be easily realized by metamaterials. It has an important applications value in the design and manufacture of slow light devices, sensors and other devices. Therefore, the use of metamaterials to achieve the analog of EIT has aroused extensive research by scholars, but most of them are based on the coupling between the bright mode and the dark mode . They focus on the design of bright and dark mode structures, and constantly put forward new bright and dark mode structures to improve the applications of using metamaterials to achieve the analog of EIT. However, there are strict requirements for the relative position between the bright and dark modes, and a little deviation will lead to the failure of the experiment. If we want to manufacture this kind of metamaterials structure, it has a strict requirement for manufacturing accuracy.
Based on the above background and significance, this paper proposes a new way to realize the analog of EIT in metamaterial. Instead of using the coupling between the bright mode and the dark mode to realize the analog of EIT effect, the dark mode which can't be excited in normal incidence can be directly excited in proposed structure, so as to realize the analog of EIT effect. In this paper, the theoretical basis of direct excitation of dark mode is introduced, then the dark mode of metamaterial which can be directly excited is proposed based on the theory and simulated by CST Microwave Studio. Finally, a high quality factor terahertz filter with center frequency of 0.471THz and quality factor of 47.1 is obtained based on the analog of EIT effect in proposed metamaterial.
Key words: Terahertz; metamaterials; dark mode; electromagnetically induced transparency; filter
目 录
摘 要 I
Abstract II
第1章 绪论 1
1.1 太赫兹技术简介 1
1.1.1 太赫兹波定义及其特性 1
1.1.2 太赫兹技术发展现状 2
1.2 超材料简介 4
1.2.1超材料定义及其特性 4
1.2.2 超材料国内外发展现状 4
1.3太赫兹超材料及其功能器件 5
1.4 本文研究意义及主要工作 6
第2章 直接激发暗模式太赫兹滤波器理论基础 7
2.1 开口谐振环基本原理 7
2.2 电磁诱导透明效应基本原理 9
2.2.1电磁诱导透明效应现象解释 9
2.2.2明模式与暗模式 10
2.3 直接激发暗模式理论基础 11
第3章 直接激发暗模式太赫兹滤波器的设计与仿真 13
3.1 CST微波工作室简介 13
3.2 开口谐振环的仿真与分析 14
3.2.1 开口谐振环结构设计 14
3.2.2开口谐振环的仿真与分析 14
3.2.3几何参数对SRR谐振的影响 15
3.3直接激发暗模式太赫兹滤波器设计与仿真 17
3.3.1直接激发暗模式太赫兹滤波器结构设计 17
3.3.2直接激发暗模式太赫兹滤波器仿真与分析 17
3.3.3几何参数对太赫兹滤波器性能的影响 19
第4章 结论 21
4.1论文工作总结 21
4.2未来工作展望 21
参考文献 22
致谢 24
第1章 绪论
1.1 太赫兹技术简介