基于电磁超介质太赫兹波传输动态可调的研究

发布时间：2018-08-01 14:23

【摘要】：太赫兹波通常被定义为0.1-10THz范围内的电磁波,在科学应用方面具有巨大潜在应用价值但缺少有效地开发。太赫兹技术发展的过程中,功能器件的集成化和智能化是必然趋势,实现太赫兹波的主动控制是至关重要的一步。目前,实现太赫兹主动控制的方法大部分都利用材料本身的非线性特性,很大程度上限制了太赫兹波传输的动态调制范围。本文基于双层材料之间热膨胀系数的差异,实现结构的三维变形,设计出一种动态可调太赫兹滤波器,具体研究内容如下:(1)将传统开口谐振环(SRR,Split-ring resonator)与可动悬臂相结合,设计出双层(Al和Si O2)可动悬臂阵列。利用双层材料之间热膨胀系数的差异,通过改变温差实现悬臂的弯曲,设计出调制范围达到0.32THz动态可调滤波器。并采用电磁理论深入分析了引起谐振偏移的物理机制。(2)本文同时采用了新型形状记忆材料(Shape Memory Material,SME)Ni Ti合金进行双层SRR可动悬臂阵列的设计仿真,理论上验证了形状记忆合金Ni Ti在超材料结构设计方面的可行性。形状记忆效应指将材料在特定条件下进行变形,通过施加适当的外界条件,材料可以恢复到变形前形状的现象。和普通金属相比,形状记忆合金具有形变量大,可恢复性和实用性强等优点。(3)为了验证形状记忆合金Ni Ti的形状记忆效应,文章采用传统光刻技术实现了SRR可动悬臂阵列样品的加工,并采用干涉仪对Ni Ti的形状记忆效应进行了表征,实验上验证了Ni Ti的可恢复效果。(4)采用太赫兹时域光谱系统(THz-TDS)对SRR可动悬臂阵列样品进行了光谱测量,详细分析了不同温度下太赫兹透射谱的变化情况。对于实验和仿真存在的差异,文中给出了详细的原因分析,并提出了进一步的优化方案。
[Abstract]:Terahertz wave is usually defined as electromagnetic wave in the range of 0.1-10THz. It has great potential application value but lack of effective development in the application of science. In the process of the development of terahertz technology, the integration and intelligence of functional devices is the inevitable trend. It is a crucial step to realize the main dynamic control of the terahertz wave. Most of the methods of Hertz active control make use of the nonlinear characteristics of the material itself, which greatly limits the dynamic modulation range of the terahertz wave transmission. Based on the difference of the thermal expansion coefficient between the double layers, the three-dimensional deformation of the structure is realized. A dynamic tunable terahertz filter is designed. The specific contents are as follows: (1) By combining the traditional SRR (Split-ring resonator) with the movable cantilever, a double layer (Al and Si O2) movable cantilever array is designed. Using the difference of thermal expansion coefficient between the double layers, the bending of the cantilever is realized by changing the temperature difference. The modulation range is designed to achieve the 0.32THz dynamic tunable filter. The electromagnetic theory is used for deep analysis. The physical mechanism that causes the resonance migration. (2) the design and Simulation of a double layer SRR movable cantilever array with a new shape memory material (Shape Memory Material, SME) Ni Ti alloy is used at the same time. In theory, the feasibility of the shape memory alloy Ni Ti in the structure design of supermaterial is verified. The shape memory effect refers to the material in a particular strip. The material can be restored to the shape before deformation by applying appropriate external conditions. Compared with ordinary metal, shape memory alloy has the advantages of large shape variable, recoverability and practicability. (3) in order to verify shape memory effect of shape memory alloy Ni Ti, the article uses traditional photolithography to realize SRR The machined cantilever array samples were processed and the shape memory effect of Ni Ti was characterized by interferometer. The recoverable effect of Ni Ti was verified experimentally. (4) the terahertz time-domain spectroscopy (THz-TDS) was used to measure the SRR movable cantilever array samples, and the changes of the terahertz transmission spectrum at different temperatures were detailed and analyzed. For the differences between experiment and simulation, the detailed cause analysis is given, and further optimization plan is put forward.
【学位授予单位】：中国科学院研究生院（光电技术研究所）
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN713;O441.4

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