【作者】 翟翔；

【导师】 范滇元； 文双春；

【作者基本信息】 湖南大学 ， 计算机应用技术， 2013， 博士

【摘要】 自从1998年美国Ebbesen科研小组在实验上观测到光在金属亚波长周期性孔阵列上的异常透射现象以来，亚波长金属结构对光波异常透射的物理机理及其应用一直都是学术界研究的热点。在光与亚波长金属结构的相互作用而引起的各种新颖现象中，表面等离激元起到了至关重要的作用。因此，对表面等离激元的激发方式、传输规律及调控手段的认识和探索，将在理论上加深和丰富人们对光与亚波长金属材料相互作用的认识；同时对基于金属表面等离激元的微纳光电器件的探究及设计，将促进新一代微型光电子器件、光电集成及全光回路等的研究进展。针对亚波长金属结构中表面等离激元的物理特性、传播规律、调控手段及相关应用等问题，本论文采用时域有限差分方法（FDTD）进行了较为系统的研究。本文的具体工作和研究结果主要有：利用数值模拟的方法对亚波长金属光栅结构中表面等离激元传播规律、行为的人工调控问题以及相关光学性质进行了比较系统的研究；通过对单缝、单缝填充介质、双缝、多缝复合加槽、三元复合金属光栅、斜入射等结构进行模拟计算了其透射谱和光场强分布，分析了透射增强的内在机理。认为，表面等离子体激元（SPPs）和类Fabry-Perot（F-P）腔是EOT现象的主要作用机制，而在多缝结构中相位共振会对透射谱产生一定影响，如劈裂的产生。研究了可见光到近红外频段的电磁波与表面等离子体亚波长复合金属光栅的相互作用，主要研究了这种亚波长金属光栅结构的色散特性以及电磁波在这种结构中的传输特性、光强分布、相位分布等物理性质。根据电磁波在亚波长复合金属光栅中的各种特性，提出了每个狭缝都含有一个垂直切口的双狭缝复合周期性金属光栅结构，研究了电磁波与这种结构的相互作用及光透射等各种特性。结果发现，当垂直切口在两狭缝中分布不对称时，该结构对电磁波的传输模式（偶/奇数波导模式）将出现不同的性质；特别是该复合周期性结构的传输谱在一定条件下出现透射最小值(dip)，该最小值的位置可以通过在狭缝中移动切口的位置进行改变。我们利用相位共振的原理合理解析了电磁波在这种含垂直切口的双狭缝亚波长周期性复合金属光栅中各种物理特性；研究还证明了垂直切口的几何尺寸对所研究的金属光栅中相位共振的影响，并结合模拟的场强和图像讨论了其物理特性。基于亚波长金属表面等离子体激元波的各种特性，研究了电磁波与金属-绝缘体-金属（MIM）光波导的相互作用及在这种波导中的传输特性。根据SPPs在MIM波导中特别是在缺陷型MIM波导结构中的物理特性，提出了一种新型的同侧双齿型MIM波导结构。深入系统地研究了SPPs在这种波导结构中的各种特性，发现此同侧双齿型MIM波导结构可以对电磁波实现滤波功能；通过调控双齿的几何结构参数，如齿的长度、宽度及两齿的中心间距等可以对滤波频率及带宽等进行有效调谐；在仅仅改变一个齿的宽度而另一个齿的宽度和其它参数保持不变的情况下，我们发现该结构对SPPs滤波的禁带宽度可以实现有效的调控；我们利用相位多重相消干涉原理合理解析了这些物理特性。由于该亚波长MIM光波导滤波器的带宽可调，该结构将对设计高集成的纳米光电器件提供一定参考价值。研究了介质圆盘金属-介质-金属光波导结构的电磁波传输、场强分布及多盘MIM结构的各种光学特性。发现多圆盘波导结构中多个圆盘的半径相同时，电磁波在其中的传输将会出现多个传播模式，且传播模式的多少与相同半径的圆盘的数量一致。同时我们发现在一个圆盘的臂膀位置对称放置两个半径、填充介质相同的圆盘时，此时的结构对电磁波的传输有漏模存在。这种多重复合圆盘结构对电磁波的传输具有调控特性。更多还原

【Abstract】 Since the Ebbesen research group observed the extraordinary transmission (EOT)phenomenon of light on metallic subwavelength periodic hole arrays in U.S. at1998,the physical mechanism of extraordinary transmission phenomenon of light waves onsubwavelength metal structures and its applications have always been research hotspots. A variety of novel phenomena caused by the interaction of light withsubwavelength metal structure, the surface plasmon polaritons (SPPs) played a crucialrole. Therefore, to understanding and exploration the SPPs’ excitation, propagationlaw and the control means will to deepen and enrich to understanding of theinteraction of light with subwavelength metallic materials. Moreover, devise andresearch the micro-nano optoelectronic devices, which based on the SPPs, willpromote the research progress of the new generation of micro-optoelectronic devicesand optoelectronic integrated and all-optical circuit, etc. Aim at the physicalproperties, control means and related applications of the SPPs in subwavelength metalstructures, in this thesis, we using the finite-difference time-domain method (FDTD)carried out a systematic study. The main research works and conclusions are asfollowing:We systemically explore the propagation properties, artificial regulationbehaviors and the related optical properties of SPPs in subwavelength metal gratingstructures by using the FDTD method. By investigate the transmission spectra andfield distributions of the single slit, single slit filled with media, double slit, multiplecompound silt with groove, ternary conpound metal grating and oblique incidencestructures, find that the SPPs and Fabry-Perot (F-P) cavity like resonance are the mainmechanism of the EOT phenomenon. Besides, the phase resonance has a certainimpact of the transmission spectra in the multiple slits structures, for example it canlead to the split.The interaction of electromagnetic waves and surface plasmon subwavelengthcomposite metal gratings are studied by using the numerical simulation method atvisible to near infrared band. Mainly include the dispersion characteristics of thesubwavelength metal grating structures and the transmission characteristics ofelectromagnetic waves, light intensity distributions, phase distributions and physicalproperties. According to various characteristics of the electromagnetic waves in subwavelength composite metal gratings, we propose a double-slit compound periodicmetal grating structure which include a vertical incision in each slit, the interaction ofelectromagnetic waves with this structure and light transmission variouscharacteristics are investigated. It is found that if the distribution of the verticalincision in the two slit asymmetries, the electromagnetic wave transmission modes(even/odd waveguide modes) in the structure will appear different properties.Especially, transmission spectra of the composite periodic structures appear atransmission minimum (dip) under certain conditions, the position of the dip can bechanged by tuning the cuts in the slits. We use the phase resonance principlereasonable to resolve the various physical properties of electromagnetic waves withvertical incision double slit subwavelength periodic composite metal grating. It is alsoproved that the geometry of the vertical incision can influence the phase resonance,combined with the field distribution to discuss these physical properties.Based on the properties of SPPs, investigated the interaction and transmissioncharacteristics of electromagnetic waves with the metal-insulator-metal (MIM)waveguide structures. According to the characteristics of SPPs in the MIM waveguidespecially in the MIM waveguide structure, we proposed a novel ipsilateraldouble-teeth shaped MIM waveguide structure. By depth study of the properties of theSPPs in this waveguide structure, it is find that this type MIM waveguide structurecan realize the typical filting function. The filtering frequency and bandwidth can betunned by adjusting the geometry of the two teeth, such as the length, width andcenter space between the two teeth. The case of simply changing the width of onetooth with the other one unchanged, we find that the band gaps of the structure of thefilter can effective regulation. We use the phase multiple destructive interferenceprinciple to reasonably resolve these physical properties. Because of thesubwavelength MIM waveguide filter bandwidth is adjustable, the structure willprovide a certain reference value to design highly integrated nanophotonic devices.Propose a multiple disk shaped coupled cavities metal-insulator-metal (MIM)waveguide sturcture and explore the transmission and the couple properties betweenoptical cavities with the same radius and different radius by2D FDTD method. Thetransmission surface plasmon waves will appear splitting modes in the coupled cavityMIM waveguide system when the radiuses of the disk cavities are the same. Thecoupled cavity systems produce the same number of spitting modes as the number ofdisk cavities. Among our findings, it is interesting to notice that there is a leak modein a coupled cavity system consisted of a cavity with two same cavities with different radius on the shoulder of it. The results are useful for the design of cavity-basedevices for integration in nanophotonics.更多还原