共查询到19条相似文献,搜索用时 156 毫秒
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光子晶体是由具有不同介电常数的物质,在空间按照周期性排列形成具有光子带隙的介电结构材料.光子带隙中的慢光子和带隙反射可以促进光子的捕获和控制光与物质之间的相互作用.基于光子晶体独特的光学特性和较大的比表面积,将光子晶体结构引入到半导体光催化材料的设计中,可以有效地增强光催化反应活性.本文介绍了三维光子晶体的制备方法及慢光子效应,总结了光子晶体特别是反蛋白石结构的光子晶体作为光催化剂在废水净化、制氢、二氧化碳的转化等领域的研究进展,并针对光子晶体光催化剂面临的挑战,提出了开发具有不同折射率和周期性的多层三维光子晶体,促进光子晶体在光催化领域的应用. 相似文献
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彭勇 《中国材料科技与设备》2014,(4):22-23
设计了一种三角晶格结构的全内反射型光子晶体光纤,并在其包层孔内分别填充折射率为n=1.55~3.35(△n=0.3)的介电材料,使其等效为全固态光子带隙型光子晶体光纤,利用全矢量平面波展开法对其带隙特性进行分析,发现随着折射率的增加,光子带隙的位置逐渐向长波方向移动,导模也越来越少。设计一种工作波长为1550nm的全固态光子带隙型光子晶体光纤,计算得到其对应的归一化传播常数β=8.2时,导模的宽度大约为100nm。该光纤在光电转换或者电光转换等方面具有潜在的应用价值。 相似文献
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阐述了完全光子禁带的概念.用光学特征矩阵方法,通过数值模拟计算,讨论了一维光子晶体出现完全光子禁带与晶体结构和介质材料的折射率的密切关系.具体计算了用同样两种介质材料组成3种不同结构的一维光子晶体,对于TM及TE电磁模式在不同入射角下的透射率谱,从中找出它们的完全光子禁带,发现3种结构的完全光子禁带的波长范围及宽度各不相同.另外,研究结果表明组成光子晶体的两种材料的折射率差别越大,两种电磁模的禁带越宽,越容易产生完全光子禁带.简单讨论了完全光子禁带出现的条件. 相似文献
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Abstract We examine the photonic band structure of two-dimensional (2D) arrays of dielectric holes using the coherent microwave transient spectroscopy (COMITS) technique. Such 2D hole arrays are constructed by embedding low-index rods (air) in a dielectric background of higher-index Stycast material (n = 3·60). The dispersion relation for electromagnetic wave propagation in these photonic crystals is directly determined using the phase sensitivity of COMITS. We find that both the square and triangular lattice structures exhibit photonic band gaps that are common to both polarizations for all wave-vectors along major symmetry axes. In addition, the connectivity of the high-index dielectric and the opening of a large gap for propagation with E field perpendicular to the hole cylinders are found to be important criteria for generating a large absolute photonic band gap. 相似文献
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Band Gap Characteristic and Transmission Spectrum of Ring-shaped Holes Photonic Crystal in THz Range
采用平面波展开法研究了2D三角晶格空气孔型光子晶体的带隙结构和空气环型光子晶体的完全带隙。结果发现空气孔半径R从0.41a到0.49a之间变化时,空气孔型的完全带隙会越大;在同一空气孔半径(R=0.41a~0.47a)下空气环型结构都能得到比空气孔结构更宽的完全带隙,得到最优参数R=0.47a,r=0.133a下的完全带隙为0.1698THz,是空气孔结构的1.15倍。使用时域有限差分法研究了空气环型结构的透射谱,根据计算结果设计了(0.7198~0.8655)THz波段的滤波器。 相似文献
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We use first order perturbation theory to study the effect of surface plasmon polaritons on the photonic band structure of plasmonic photonic crystals. Our results are based on a simple numerical tool that we have developed to extend the standard frequency domain methods to compute the photonic band structure of plasmonic photonic crystals. For a two-dimensional honeycomb photonic crystal with a lattice constant of 500 nm placed on an aluminium substrate, we show that the band gap for TM modes is enhanced by 13%. Thus a slight variation in the effective dielectric function results in a plasmonic band structure that is not scale-invariant, which is reminiscent of the inherent non-linear properties of the effective dielectric constant. 相似文献
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A. Sedghi 《Journal of Modern Optics》2018,65(2):145-150
Using the Dirichlet-to-Neumann map method and generalization of this method, we have been able to calculate the photonic band structure of two-dimensional (2D) metallodielectric photonic crystals composed of metal-coated circular dielectric rods. The rods are embedded in an air background with a square array. We are interested in considering transverse electric (TE) mode of electromagnetic waves. The resulting band structures show the existence of photonic band gaps as well as some flat band regions. We theoretically study the effect of the dielectric constant and radius of the dielectric core on the photonic band structures. There are some interesting results compared to the case of solid metallic rods (without dielectric core) such as appearing the new photonic band gaps and a flat band region with the characteristic of cavity modes. 相似文献
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利用遗传算法和传输矩阵法计算一维光子晶体能带结构,将一维光子晶体用像素填充法进行二进制编码模拟,结果找到全方位相对禁带宽度达42.54%的4层结构和43.75%的2层结构;给出了一维光子晶体4层最佳结构的能带图、20个原胞的反射率透射率频谱图.发现一维2层光子晶体的全方位禁带宽度对每层厚度的变化是不敏感的,但是随着两种介质折射率差的增大而增大. 相似文献
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An index-guided, two-dimensional photonic crystal fiber (PCF) with triangular lattice and solid air core was designed and investigated using the effective index method. A modal analysis of three-ring elliptical air hole photonic crystal fiber is presented: first the innermost ring was made elliptical and then the cells of the inner two rings were made elliptical and finally all three rings contained elliptical cells. The above configuration was then compared with three-ring circular air hole photonic crystal fiber keeping the area of air holes and simulation parameters of the wafer the same to obtain the fundamental space-filling mode (FSM). The analysis was performed using full vector FDTD for TE and TM polarizations. The complex effective refractive index generated was then used to calculate the chromatic dispersion and birefringence properties of the PCF. 相似文献
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The effect of temperature on a two-dimensional square lattice photonic crystal composed of Si rods arranged in an air background was investigated theoretically using the plane-wave expansion method. Both the thermal expansion effect and thermo-optical effect are considered simultaneously. We have discussed the role of temperature in creating the complete photonic band gap as a function of temperature. Two different shapes of rods, i.e. square and circular, are considered in the presence of the two polarization states, i.e. TE and TM waves. The numerical results show that the photonic band gap can be significantly enlarged compared to the photonic band gap at room temperature. The effect of temperature on the complete photonic band width in the cylindrical rods case is more significant. Cylindrical and square Si rods may work as a temperature sensor or filter, among many other potential applications. 相似文献
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AbstractIn this study, we analyse the evolution of complete photonic band gap in two-dimensional photonic structures by arranging the 12-fold symmetric quasicrystalline unit cells on square and triangular lattices. The unit cells composed of circular air holes in anisotropic tellurium background and the air holes are infiltrated with liquid crystal. Using the supercell method based on plane wave expansion, we study the variation of complete band gap by changing the optical axis orientation of liquid crystals. 相似文献