太赫兹波段的超材料调制器的研制与设计

发布时间：2018-03-29 09:40

本文选题：超材料　切入点：太赫兹调制器　出处：《电子科技大学》2017年硕士论文

【摘要】：本文主要基于电磁超材料的特性完成以下三部分的工作:极化不敏感的电磁诱导透明效应(electromagnetically induced transparency effects,EIT)的调制器设计,多频带谐振调制器的设计与研制,低电导率材料的超宽带吸收调制器设计。在EIT效应的太赫兹调制器设计中主要完成以下三部分的工作:首先,完成亮-亮模式耦合的极化不敏感EIT效应的太赫兹调制器的设计,电磁诱导透明点在0.828 THz,Q值为15.3,通过800 nm激光照射半导体衬底改变电导率设计出两种调制方式,透明点幅度调制深度分别为73%与34%。其次,完成亮-暗模式耦合的极化不敏感EIT效应的太赫兹调制器设计,透明点在0.3 THz,Q值为150。最后,通过研究两种器件的互补结构发现在EIT的频带内互补原理不适用的现象。在多频带调制器的设计与研制中主要完成以下四部分的工作:首先,设计实现一种加载螺旋臂的结构双频带谐振结构,谐振结构的谐振频点分别为0.28 THz、0.59 THz,利用激光照射半导体设计两种调制方式:第一个谐振点的S21的幅度调制深度为54.8%和两个谐振点的S21的幅度同时的调制深度为54.8%;其次,在双频带谐振结构上添加L型金属结构实现三频带谐振结构,谐振频点分别为0.256THz、0.49 THz、0.67 THz;然后,利用激光照射在三频带谐振结构实现分别对第二个频点与第三个频点的S21幅度的调制,调制深度为54.8%,也可以实现对三个频点S21幅度的同时调制,调制深度为41%;最后,完成实物加工与测试,测试与仿真S21曲线吻合良好。在基于低电导率材料的超宽带可调吸收器设计中主要完成以下两方面的工作:首先,利用低电导率的合金材料以开口环为基础设计出超宽带的吸收结构,半峰值吸收带宽为4 THz,相对吸收带宽Bw=108%,通过激光照射到嵌入结构中的硅半导体实现x极化入射波的半峰值吸收带宽在2.4 TH-3.8 THz之间动态调制。其次,在开口环结构为基础设计对称的复合吸收结构,实现半峰值吸收带宽为4.3 THz,相对带宽Bw=118%的超宽带吸收结构,并通过激光激励嵌入结构中的硅半导体可以实现吸收带宽在1.7 THz-4.1 THz间的调制。
[Abstract]:Based on the characteristics of electromagnetic metamaterials, the following three parts have been completed in this paper: the design of electromagnetic induced induced transparency effects modulator, the design and development of multi-band resonant modulator. The design of ultra-wideband absorption modulator for low conductivity materials. In the design of terahertz modulator for EIT effect, the following three parts are accomplished: firstly, the design of terahertz modulator with bright bright mode coupling polarization insensitive to EIT effect is completed. The electromagnetically induced transparency point is 15.3 at 0.828 THZN Q. Two modulation methods are designed to change the conductivity of semiconductor substrate by 800 nm laser irradiation. The amplitude modulation depth of the transparent point is 73% and 34% respectively. A terahertz modulator for polarimetric insensitive EIT effect with bright dark mode coupling is designed with a transparent point of 0. 3 THZ Q of 150. Finally, By studying the complementary structure of the two devices, we find that the complementary principle is not applicable in the frequency band of EIT. In the design and development of the multi-band modulator, the following four parts are accomplished: first, A dual-band resonant structure with a loaded spiral arm is designed and implemented. The resonant frequency of the resonant structure is 0.28 THzN 0.59 THZ respectively. Two modulation modes are designed by laser irradiation semiconductor: the amplitude modulation depth of S21 of the first resonant point is 54.8% and the amplitude of S21 of the two resonant points is 54.8% at the same time. The three-band resonant structure is realized by adding L-type metal structure to the dual-band resonant structure. The resonant frequency points are 0.256 THzN 0.49 THzN 0.67 THZ respectively. The modulation of S21 amplitude of the second frequency point and the third frequency point is realized by laser irradiation in three frequency band resonant structure. The modulation depth is 54.8. the modulation depth of the S21 amplitude of the three frequency points can also be realized simultaneously, and the modulation depth is 41. The test and simulation S21 curves agree well with each other. In the design of ultra-wideband tunable absorber based on low conductivity material, the following two aspects are accomplished: first of all, The absorption structure of UWB is designed by using low conductivity alloy material based on open ring. The half-peak absorption bandwidth is 4 THZ, and the relative absorption bandwidth is Bwn 108. The half-peak absorption bandwidth of x polarization incident wave is dynamically modulated between 2.4 TH-3.8 THz and 2.4 TH-3.8 THz by laser irradiation to the silicon semiconductor embedded in the structure. A symmetrical composite absorption structure is designed on the basis of the open ring structure. The half-peak absorption bandwidth is 4.3 THZ and the relative bandwidth is 11.8%. The modulation of absorption bandwidth of 1.7 THz-4.1 THz can be realized by laser excited silicon semiconductor in embedded structure.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN761

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