基于超材料的太赫兹功能器件

发布时间：2018-02-03 13:35

本文关键词： 太赫兹超材料电磁诱导透明电磁诱导吸收超表面表面波传感　出处：《天津大学》2015年博士论文　论文类型：学位论文

【摘要】：太赫兹技术是世界范围内备受瞩目的研究方向,在很多前沿领域都有着潜在的应用前景。开发太赫兹功能器件将在很大程度上促进太赫兹技术的实用化进程。然而,目前基于传统方法的太赫兹功能器件还很稀少或昂贵。超材料作为一种性质可控的电磁材料,为设计太赫兹功能器件提供了一种有效的方法。本论文详细研究了多种基于超材料的太赫兹功能器件,具体内容如下:1.用超材料类比地实现电磁诱导透明这一量子现象吸引了研究人员的兴趣。然而,目前的电磁诱导透明超材料都强烈地依赖入射光的偏振。这里,本论文提出了一种超材料,它由具有4次旋转对称性的微结构组成。实验和模拟结果显示它可以实现偏振无关的电磁诱导透明现象。利用耦合模理论,很好地对该结构的工作机制进行了解释。该偏振无关特性将使得它更加适用于实际应用。2.目前,用超材料类比地实现电磁诱导吸收这一量子现象的工作还很少,现有的此方面工作对于电磁波的吸收程度还很小。这里,本论文提出了一种由三种微结构振荡器组成的电磁诱导吸收超材料,可以强烈地吸收太赫兹波。实验、模拟和理论结果吻合得很好。该设计将在吸收性光开关方面有重要的应用价值。3.用超表面控制电磁波的相位突变已成为了一个热点话题,这种用微结构来局域地控制电磁场出射相位的方法几乎可以生成任意的波前形状。这里,本论文提出了一种C形振荡器来控制太赫兹波的相位和波前,设计并在实验上证明了一个宽带的太赫兹平面型偏折分光器和一个奇异菲涅尔波带片,结果与理论预测非常吻合。该设计在实现太赫兹空间波调制器方面有重要的应用前景。4.当前,大多数用于相位控制的超表面器件都基于金属,其电磁波操控效率较低且面临欧姆损耗问题。这里,本论文提出了一种基于硅的介质超材料,用于高效地控制太赫兹波的相位。在此基础上,又引入了振幅控制机制,设计了三种奇异光栅,其实验结果和理论与模拟结果吻合得很好。该设计将在高效率太赫兹空间波调制器件方面有重要的应用前景。5.表面波是一种传播在金属和介质界面处的电磁波,在下一代芯片光路器件方面有着重要的应用前景。这里,本论文将自由空间中的超表面相位控制的概念引入到了表面波激发中,利用金属孔结构实现了偏振控制的异常表面波激发和聚焦、发散形的表面波波振面,且该结构还可用于传感入射波的偏振态以及外界的折射率变化。该设计将在实现太赫兹电路方面有潜在的应用价值。
[Abstract]:Terahertz technology is one of the most attractive research directions in the world. The development of terahertz functional devices will greatly promote the practical process of terahertz technology. At present, terahertz functional devices based on traditional methods are rare or expensive. Metamaterials are considered as a controllable electromagnetic material. It provides an effective method for the design of terahertz functional devices. In this paper, a variety of terahertz functional devices based on metamaterials are studied in detail. The quantum phenomenon of electromagnetically induced transparency by analogy with metamaterials has attracted the interest of researchers. At present, the electromagnetically induced transparent metamaterials are strongly dependent on the polarization of incident light. In this paper, we propose a kind of metamaterials. The experimental and simulation results show that the polarization-independent electromagnetically induced transparency can be realized by the coupled mode theory. The work mechanism of the structure is well explained. The polarization independence will make it more suitable for practical application. 2. At present. The quantum phenomenon of electromagnetic induced absorption by analogy of metamaterials is still rare, but the extent of absorption of electromagnetic wave is still very small. In this paper, an electromagnetic induced absorption supermaterial consisting of three kinds of microstructured oscillators is proposed, which can strongly absorb terahertz waves. The simulation results are in good agreement with the theoretical results. This design will have an important application value in absorbing optical switch. The phase change of electromagnetic wave controlled by supersurface has become a hot topic. This method can produce almost arbitrary wavefront shape by using microstructures to control the phase of electromagnetic field. Here, a C-shaped oscillator is proposed to control the phase and wavefront of terahertz wave. A wideband terahertz planar deflector and a singular Fresnel band plate are designed and experimentally proved. The results are in good agreement with the theoretical prediction. This design has an important application prospect in the realization of terahertz spatial wave modulator. At present, most of the supersurface devices used for phase control are based on metal. The electromagnetic wave control efficiency is low and it faces ohmic loss problem. In this paper, a silicon based dielectric supermaterial is proposed to efficiently control the phase of terahertz wave. The amplitude control mechanism is introduced and three kinds of singular gratings are designed. The experimental results are in good agreement with the simulation results. This design will have an important application prospect in high efficiency terahertz space wave modulator .5.The surface wave is a kind of electromagnetic wave propagating at the interface between metal and medium. Bo. In this paper, the concept of supersurface phase control in free space is introduced to the surface wave excitation. The polarization controlled abnormal surface wave excitation and focus and the divergent surface wave vibration surface are realized by using metal pore structure. The structure can also be used for sensing the polarization state of incident wave and the change of refractive index of the outside world. This design will have potential application value in the realization of terahertz circuit.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：O441.4

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