一维光子晶体的带隙特性研究

一维光子晶体是指介质只在一个方向呈周期性排列的材料。利用薄膜光学的特征矩阵法研究了一维光子晶体的禁带特性，分析了填充率变化、厚度的随机扰动对光子带隙的影响。结果表明，各能级的带隙率随填充率的变化而变化，并且存在一个极大值；厚度的随机扰动对光子带隙也有一定影响，但随机度不同，对光子带隙的影响也不一样。     

光子晶体的制备方法

光子晶体是周期性的电介质结构,这种结构具有光子禁带,具有光子带隙是其最根本的特征。介绍制备光子晶体的主要方法:机械打孔法、层层堆积法、胶体自组装法、激光全息干涉法。     

一维光子晶体的带隙特性研究

一维光子晶体是指介质只在一个方向成周期性排列的材料。利用薄膜光学的特征矩阵法研究了一维光子晶体的禁带特性,分析了填充率变化、厚度的随机扰动对光子带隙的影响。结果表明,随着填充率的变化,各能级的带隙率变化,并且存在一个极大值;厚度的随机扰动对光子带隙也有一定的影响,随机度不同,对光子带隙的影响也不一样。本研究对一维光子晶体的设计与制备有一定的参考价值。     

一维光子晶体完全光子禁带与结构的关系

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.     

光子晶体应用于浓度检测的模拟研究

采用平面波展开法数值计算二维光子晶体在TE和TM偏振态下的带隙,给出了光子晶体中的禁带存在的理论依据,选择二维三角晶格光子晶体（GaAs）作为基底,在气孔内填充浓度为一定的待测溶液硫酸铜材料,计算温度为298K情况下介电常数在71．917～62．530变化时,光子晶体在不同偏振模式下的光子禁带结构,结果表明,以硫酸铜的水溶液作为空气圆孔中的介质材料,当溶液质量百分浓度不同时光子带隙（PBG）发生显著变化。     

3．0μm～4．0μm全角度反射镜

分析了一维光子晶体的光子能带结构和禁带特性;然后利用光子禁带特性,设计了3.0～4.0μm全角度反射镜,给出了其反射光谱.     

光子晶体--一种新型人工带隙材料

光子晶体是近十年来才发展起来的存在光子禁带的一种新型人工材料,具有操控光子行为的独特能力,在众多领域有着广泛的用途.介绍了光子晶体的结构特征,分析了光子带隙产生的物理机理,着重介绍了光子晶体材料中存在的新现象及其应用.     

精确的一维光子晶体的带隙

半导体材料的折射率是光频率的函数,所以在计算光子晶体的能带结构时必须考虑到色散关系。光子晶体存在光子禁带在反射谱上表现为高反射率带。本文已GaAs基材料为例,利用传输矩阵方法计算了考虑色散后的一维光子晶体的反射谱,计算结果表明考虑色散后的光子晶体禁带的宽度较不考虑色散关系的光子晶体的带隙要窄,如果光子晶体中存在缺陷则考虑色散后的光子晶体缺陷态的位置较不考虑色散关系时红移,且光子损耗较小。     

光子晶体在光催化领域的研究进展

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.     

二维旋转直柱光子晶体的频率带隙结构分析

设计了一种二维方形旋转正四边形直柱光子晶体,利用平面波展开方法计算了其光子频率带结构,发现在低频和高频区域,该类光子晶体的光子频率禁带明显增大.计算了空气中Al材料的旋转四边形直柱光子晶体的带结构和态密度,当填充比等于0.5时存在绝对带隙,旋转角度为45°时绝对带隙最大,旋转角度为0时,光子频率禁带位于高频区域.利用FDTD方法检验了计算结果,并分析了旋转角度为45°时,正四边形直柱光子晶体的波导特性以及TM模的电场分布.     

Structural and optical quality of binary photonic crystal heterostructures fabricated by the modified self-assembly method

Photonic crystal heterostructures constituting of two photonic crystals with different lattice constants are fabricated using the modified self-assembly method and their structural and optical properties are investigated. The results show that these photonic crystal heterostructures of high quality possess deep photonic band gaps and steep photonic band edges in their transmission spectra. Deep double photonic band gaps, steep photonic band edges and high transmittance in the pass band show good ordering of the heterostructure and may offer a probability for studying late-model ultra-fast all-optical switches.     

Genetic optimization of two-dimensional photonic crystals for large absolute band gaps under light line

A binary genetic algorithm with floating crossover and mutation probabilities is used to design two-dimensional photonic crystals for large absolute band gaps under a light line. The unit cell is composed of a small number of round rods and is arranged in a square lattice. The photonic band structure of each chromosome is calculated by the plane-wave expansion method. Starting from randomly generated photonic crystals, the genetic algorithm finally yielded a photonic crystal with an absolute common band gap of 0.0618(2πc/a) at the mid-frequency of 0.4084(2πc/a).     

基于声子晶体的车内噪声研究

声子晶体是近年来提出的一种新型功能材料,是一种由两种或多种材料组成的具有周期性结构和弹性波带隙的声学功能材料或结构,并且振动频率在声子晶体带隙范围内的振动会被抑制或禁止传播,它所具有的这种弹性波带隙特性为汽车车内噪声控制,特别是车内低频噪声控制提供了一种新的研究方法.在介绍了声子晶体的概念、基本特征及能带结构的基础上,阐述了声子晶体在振动与噪声控制领域的研究现状,同时对车内噪声的产生机理进行了分析,最后对声子晶体在应用于汽车车内降噪方面的研究做了展望.     

Investigation of TE-polarized photonic band gap properties in matallodielectric photonic crystals composed of metal coated dielectric cylinders

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.     

光子晶体的能带结构、潜在应用和制备方法

光子晶体是指具有光子能带和能隙的一类新型材料,它具有奇特的调节光子传播状态的特性．本文将从光子晶体的能带结构、潜在应用和制备方法三方面对其进行综述性介绍．由于光子晶体有着非常广阔的应用前景,这一领域已成为当今世界范围内的研究热点．     

二氧化硅胶体晶体的制备及其光子带隙特性

利用胶体颗粒悬浊液的自组织生长技术制备了两种二氧化硅胶体晶体．透射光谱表明：所制备的胶体晶体的光子带隙位于近红外波段,带隙的位置随胶体晶体中胶粒的尺寸而变化;且放置时间延长,带隙将发生蓝移．     

聚合物凝胶光子晶体及其对物理环境的响应

文中简要介绍了物理响应性光子晶体的国内外研究动态。重点介绍以下几种物理响应性光子晶体:温度响应性光子晶体,溶剂响应性光子晶体,电场响应性光子晶体,磁场响应性光子晶体,机械力响应性光子晶体等。     

Photonic crystals,amorphous materials,and quasicrystals

Photonic crystals consist of artificial periodic structures of dielectrics, which have attracted much attention because of their wide range of potential applications in the field of optics. We may also fabricate artificial amorphous or quasicrystalline structures of dielectrics, i.e. photonic amorphous materials or photonic quasicrystals. So far, both theoretical and experimental studies have been conducted to reveal the characteristic features of their optical properties, as compared with those of conventional photonic crystals. In this article, we review these studies and discuss various aspects of photonic amorphous materials and photonic quasicrystals, including photonic band gap formation, light propagation properties, and characteristic photonic states.     

Planar waveguide photonic crystals as an alternative for refractive index optical sensors design: theoretical evaluation

In this paper, the possibilities of designing refraction index optical sensors in planar waveguide photonic crystals are demonstrated for the first time. Photonic crystals obtained by connecting in cascade planar optical waveguides with high index contrast are analyzed. Photonic band gaps (PBGs) and photonic windows (PWs) were obtained. If a local defect is introduced in the PBG structure, the optical path length is modified and on states can be created in the gap. Besides, the on states wavelengths can be tuned if the optical path of the defect is modified: changing the physical length and/or the refraction index of the defect. In this way, planar waveguide photonic crystals could be used for sensing applications when a specimen modifies the refraction index lattice site. Sensing properties of planar waveguide photonic crystals, with one, two and three sensing channels, are demonstrated.