超薄人工表面等离子体激元结构及其应用研究

发布时间：2018-04-03 12:09

本文选题：表面等离子体激元　切入点：人工表面等离子体激元　出处：《南京大学》2015年博士论文

【摘要】：表面等离子体激元(Surface Plasmon Polaritons,SPPs)是一种沿金属/介质分界面传播的表面电磁波。由于它具有强的电磁场束缚能力,可以有效减小光电子器件及电路的尺寸,从而吸引研究人员的广泛关注。在微波或者太赫兹波段,金属通常近似为理想导体,在光滑金属表面不能激发出表面等离子体激元。最近,J.B.Pendry等提出一种人工等离子体材料,该材料可以在低频段支持类似表面等离子体激元的电磁波传播,被称为人工表面等离子体激元(spoof SPPs)。目前大多数人工等离子体材料属于三维金属/介质结构,制作难度大,也不容易与现有的平面微波、太赫兹波电路集成。为了克服这些缺点,崔铁军教授等人提出了一种超薄人工等离子体材料来支持人工表面等离子体激元,由于该结构具有超薄、工艺简单、可弯曲、可共形于任意表面等特点,因此,在开发各种各样的低频表面波集成电路或器件上具有重要的应用前景。鉴于上述发展趋势,本文着重开展超薄人工表面等离子体激元结构及其应用研究。在详细分析了超薄人工表面等离子体激元结构的各类传播模式基础上,根据人工表面等离子体激元的特点,设计了一系列人工表面等离子体激元原型器件,例如分波器、耦合器、滤波器、谐振器等,并且首次设计并实现了支持反向波传输的人工表面等离子体激元结构。本文主要内容和研究成果概括如下:(1)理论分析了非对称超薄人工表面等离子体激元结构的基本模式和高阶模式的色散性质和传输特性,提出了高次模式出现的条件并进行了实验验证。在此基础上仿真分析和实测了高阶人工表面等离子体激元模式在弯曲结构上的传输性能,具有弯曲损耗相对较小的特点,这为利用该结构的高阶模式设计原型器件提供了重要的参考依据。(2)理论分析了对称超薄人工表面等离子体激元结构所支持的基本模式,包括奇、偶两种不同模式。提出了一种激励奇模式的方法,通过仿真分析和实验测量对应的传输谱,验证了该方法的有效性。此外本文还提出了一种新的对称结构,在特定频段对人工表面等离子体激元具有更强的束缚性和更低的传输损耗,为实现器件或电路的小型化提供了可能。(3)开展了基于超薄人工表面等离子体激元结构原型器件的研究。首先,根据耦合模式理论,提出了一种利用对称超薄人工表面等离子体激元结构的偶模式设计太赫兹波分波器和耦合器的方法。利用缩放性,设计了对应的工作在微波波段的分波器和耦合器,并通过微波实验测量验证了该器件的性能;其次,根据人工表面等离子体激元的单模传输特性,通过在低频端增加了一个传输零点,实现了同时具有宽通带和宽阻带特性的带通滤波器。该滤波器可以有效克服超宽带微带线滤波器难以实现宽阻带特性的缺点;第三,提出了一种具有接地板的非对称超薄人工表面等离子体激元结构,该结构所支持模式的辐射损耗大为减小。利用该结构的第一阶高阶模式实现了带宽和中心频率都可灵活调节的带通滤波器;最后,利用对称超薄人工表面等离子体激元结构设计了直线型谐振器,通过对其Q值分析提出了提高Q值的办法。此外通过测量谐振器的Q值,提出了间接测量人工表面等离子体激元结构色散曲线和对应的衰减系数的方法。(4)提出了一种新型对称超薄人工表面等离子体激元结构,可支持具有反向波特性的人工表面等离子体激元传播。利用其反向波特性,设计了一个微波反向耦合器,并通过实验进行了验证。这将有助于设计新颖人工表面等离子体激元器件或电路结构。
[Abstract]:The surface plasmon (Surface Plasmon, Polaritons, SPPs) is a kind of metal / dielectric interface along the propagation of surface electromagnetic wave. Because it has a strong binding capacity can effectively reduce the electromagnetic field, optoelectronic devices and circuit size, so as to attract the attention of researchers. In the microwave or terahertz band, metals are usually approximated as a perfect conductor and in smooth metal surface can not excite surface plasmon. Recently, J.B.Pendry proposed a kind of artificial plasma material, the material can support similar surface plasmon propagation of electromagnetic wave element at low frequencies, known as artificial surface plasmon (spoof SPPs). The 3D metal / dielectric structure most of artificial plasma materials is difficult to produce, is not easy with the existing planar microwave, terahertz wave integrated circuit. In order to overcome these shortcomings, Cui Tie Professor Jun et al proposed a thin artificial plasma material to support artificial surface plasmon, because the structure has the advantages of simple technology, ultra-thin, flexible, conformal to arbitrary surface characteristics, therefore, it has important application prospect in the development of a variety of surface acoustic wave integrated circuit or device. In view of the development trend in this dissertation, ultrathin artificial surface plasmon structure and its application. Based on a detailed analysis of all kinds of artificial propagation modes of ultra-thin surface plasmon structure, according to the artificial table characteristics of surface plasmon, designed a series of artificial surface plasmon prototype devices, such as filters, couplers, filters. The first resonator, and the design and implementation of artificial surface plasmon wave structure to support reverse transmission. The main contents and research The results are summarized as follows: (1) the theoretical analysis of the dispersion properties and transmission characteristics of the basic pattern of asymmetric thin artificial surface plasmon structure and high order mode, put forward the condition of the high order mode and verified. Based on the simulation analysis and the measured transmission performance of the high order artificial surface plasmon excitation in the structure of the bending mode, has the characteristics of bending loss is relatively small, which provides an important reference for the design of the prototype of high order mode device structure. (2) the basic pattern, symmetrical ultrathin artificial surface plasmon structure supported by theoretical analysis including odd, even two different modes put forward a way to motivate the odd mode, transmission through simulation analysis and experimental measurement of the corresponding spectrum, verify the effectiveness of the method. This paper also puts forward a new structure of said, The transmission loss in specific bands is more artificial surface plasmon and the lower bound, provides the possibility for the miniaturization of the device or circuit. (3) studied ultra-thin artificial surface plasmon devices based on the prototype structure. First of all, based on coupled mode theory, puts forward a method of terahertz I design model using symmetric thin artificial surface plasmon wave structure and WDM coupler. Using the zoom, design the corresponding work in WDM coupler and microwave band, and the performance of the device was verified by experiments in microwave measurement; secondly, according to the artificial surface plasmon single-mode element in the end, by adding a low frequency transmission zeros, and has achieved wide passband bandpass filter with wide stopband. The filter can effectively overcome the ultra wideband micro Strip line filter cannot achieve wide stopband shortcomings; third, a non symmetric thin artificial surface plasmon ground structure, radiation loss mode supported by this structure is greatly reduced. The band-pass filter to achieve bandwidth and center frequency can be flexibly adjusted by first order higher order mode the structure; finally, using the symmetric thin artificial surface plasmon structure linear resonator is designed, based on the analysis of Q value is proposed to improve the Q value of the solution. In addition by measuring the Q value of the resonator is proposed, the attenuation coefficient of indirect measurement of artificial surface plasmon dispersion curves and the corresponding structure. (4) proposed a new symmetric thin artificial surface plasmon structure, which can support the artificial surface plasmon propagation with reverse wave characteristics. Using the reverse wave characteristics, A microwave reverse coupler is designed and verified by experiments. This will help to design a novel artificial surface plasmon device or circuit structure.

【学位授予单位】：南京大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN713;TN62

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