【作者】 邓立儿；

【导师】 王永生；

【作者基本信息】 北京交通大学 ， 光学， 2010， 博士

【摘要】 光子晶体由于具有独特的调节光子传播状态的功能,是光电集成和光通信的基础材料,有关光子晶体的研究是目前信息功能材料研究的前沿领域。本论文理论部分以一维光子晶体为研究对象,计算模拟了不同结构光子晶体的光学特性；实验部分围绕以三维胶体晶体为模板制备得到的有序大孔材料展开,系统研究了其形成机理、微观结构、带隙性质及应用。主要内容包括以下几个方面：1.针对普通光子晶体全反射镜的两大缺点,设计了宽频带一维三元光子晶体异质结构全方向反射镜,异质结构有效的增大了全反镜的工作带宽,三元结构可以降低对制备精度的要求。基于一维光子晶体超晶格的多通道滤波器中,通过改变晶格的结构参数即可以很方便的调节光子禁带中透射带的数目以及透射带中透射峰的数目。讨论了分别由Al、Ag、Au、Cu四种金属和SiO2构成的金属／电介质型光子晶体的透射和吸收光谱以及这两者之间的关系,结果表明光子晶体中金属的吸收行为并不只是跟光子晶体的带隙结构有关,而更多的是取决于晶体中电场的空间分布情况。2.采用改进的垂直沉积法制备了各种不同粒径微球的聚苯乙烯胶体晶体模板并对它们进行了表征。针对目前TiO2反蛋白石结构制备中的填充率低、易塌陷、表面平整度差、成品率低、尺寸微小等缺陷,使用优化调整的溶胶-凝胶技术结合模板技术、高温煅烧技术制备得到了大面积周期有序的TiO2多孔结构。扫描电镜照片显示,其结构表面平整,塌陷和缺陷极少。以稀土Tb3+作为探针,研究了TiO2反蛋白石结构的光子带隙对其自发发射光谱的调制,观察到了光子带隙对处于其禁带中心的光发射的抑制和处于其短波带边的光发射的增强。3.以SiO2胶体晶体为模板,使用单体填充而后加热聚合的方法制备了PMMA反蛋白石结构光子晶体,其大孔结构有序性非常良好,在数百平方微米范围内单晶连续无裂纹。利用聚合物PMMA透明、柔韧性高的特点,制备得到了平方厘米量级的柔性可卷曲的反蛋白石结构光子晶体薄膜,这种薄膜可以像卷纸一样被卷曲数圈而不破裂。研究了PMMA反蛋白结构光子晶体对置于其中的有机发光小分子Alq3的自发发射光谱的影响,Alq3的发射光谱在光子带隙处出现了一个凹陷,从而导致了466nm处另一发射峰的出现。二次模板法制备得到了PMMA微球的有序阵列,可以预测,通过往二次模板ZnO反蛋白石结构的孔隙中填充入不同的材料即可得到具有各种功能的微球的周期有序阵列。更多还原

【Abstract】 Photonic crystals (PCs) have attracted much attention because of their ability to manipulate, confine and control light, and the investigation of the PCs are the frontier of functional materials. This dissertation composed of two parts:theoretical calculations and experimental preparation. The first part focuses on the one-dimensional PCs。The optical properties of PCs with different structures are analyzed numerically. In the second part, we prepared macroporous materials by using opal template and form mechanism, microstructures, band structure and applications of the macroporous structures were studied systematically. The important results are given as followings:1、Using transfer matrix method (TMM), we have studied the band structure, electric field distribution, dispersion relation, defect propagation characteristics of one-dimensional dielectric-dielectric photonic crystals. The transmission and absorbent properties of one-dimensional metal-dielectric photonic crystals composed of different metals (Al、Ag、Au、Cu) were discussed. The results showed that the electric filed distribution played a more decisive role than the photo states distribution in the metallic absorption characteristics.2、High-quality polystyrene (PS) colloidal crystals were prepared by a improved vertical deposition technique. Centimeter-sized surface-smooth thin film TiO2 inverse opals were obtained by a sot-gel process using the polystyrene colloidal crystal template. From the SEM photograph, we can see that the macroporous structures of the inverse opals are orderly and non-dilapidated. The photonic bandgap effect on the spontaneous emission of Tb3+ was investigated. The suppression at 540nm and enhancement at 484nm in the fluorescence spectrum were interpreted in terms of redistribution of the photon density of states in the photonic crystal.3、Ordered macroporous polymers have been prepared by replication of SiO2 colloidal crystals. The air between the silica spheres was filled by the monomer of poly(methyl methacrylate) (PMMA) that can be subsequently polymerized at 80℃. We obtained the flexible and free-standing PMMA inverse opal polymers films with large area using of the formation of an overlayer of PMMA. The film is enough tough to be curled to various shape. These flexible polymers films can extend the usage of macroporous structures and have potential applications. The spontaneous decay of emitting species can be modified by changing its environment. We have fabricated inverse opal embedded with Alq3 to investingate the photonic bandgap effects on the spontaneous emission. The dip appeared in the fluorescence spectrum was interpreted in terms of redistribution of the photon density of states in the photonic crystal. The results indicated that the suitable combination of fluorescence materials and the photonic crystals can provide a promising route to design and fabricate the light-emitting diodes, low-threshold lasers and other highly efficient optical apparatus. PMMA microsphere arrays are fabricated by a double replicating method. High quality ZnO inverse opals prepared without extra defects formed by electrodeposition. After the subsequently in-situ polymerization of MMA in the voids of ZnO inverse opals, the ZnO is removed by hydrochloric acid solution.更多还原