Much effort has focused on eliminating these unwanted defects from the self - assembled material , and extremely ordered photonic bandgap crystals have been made . however people ca n ' t control the defect during the self - assembling 在本方法的基础上利用光镊技术对产生的缺陷进行修复以及对生成的晶体进行修整，从而达到去除缺陷的目的，生成大面积无缺陷的的三维光子晶体。
In the transmitted wave , along with the extinction coefficient increment , the width of photonic bandgap is a gradual extension , the edge of photonic bandgap is a gradual faintness , when the extinction coefficient increases to 0 . 02 , there is already no obvious photonic bandgap 在透射波中，随着消光系数的增加，禁带宽度逐渐扩大，禁带边缘逐渐模糊，当消光系数增加到0 . 02时，已经不存在明显的能带。
The dual - core air - guided photonic bandgap fiber couplers are designed and decoupling phenomenon has been found . coupling properties of the pbgfs with two adjacent air holes as fiber cores are analyzed . the decoupling point , where there is no 对具有两个相邻纤芯的空气传导光子带隙光纤的传导模式和耦合特性进行了理论分析,在所分析的结构中发现了无耦合点,在该波长处两个相邻纤芯之间不发生能量转移。
The haronics at the output is terminated especially to the second harmonic , in order to improve the output power and efficiency . we present a new method for harmonic tuning by using photonic bandgap ( pbg structure at the output of the power combiner in this thesis 我们在功率合成器的输出端使用二维微带pbg结构进行谐波调谐，用来提高合成器的输出功率。最后，讨论了功率合成中幅度、相位对合成效率的影响及系统的“适度恶化”现象。
The details are described as follows : 1 . the photonic bandgap theory based on total internal reflection ( tir ) pcfs filled with by high index material ( nlc ) is proposed for the first time . based on this theory , the effects of nlc - filled tir - pcfs on the transmission mechanism and propagation properties are studied using plane - wave method and full - vector fem 主要研究内容和成果包括以下基本方面: 1 、首次提出基于填充高折射率介质(液晶)的折射率引导型pcf的光子带隙理论分析方法,在此理论的指导下,采用平面波展开法和有限单元法研究了填充对光纤传导机制和传输特性的影响,研究结果表明液晶填充可以实现光子晶体光纤导光机制的转变。
We study the photonicband structure of the mof cladding with triangular and honeycomb air holes lattices . then the guided mechanisms of mofs are demonstrated . the guided properties such as waveguide dispersion , effective modal area and nonlinearity for both index - guided mof and photonic bandgap mof are presented 从研究微结构光纤的传导机制和传导模式出发,分析不同结构的光子晶体包层的能带结构,研究折射率传导和光子带隙传导两种机制下光纤的传导模式及色散、损耗和有效模场面积等基本特性。
Based on the simulation method of finite difference time domain ( fdtd ) ( together with the boundary treatment of an anisotropic perfect matched layer of absorbing media for the truncation of fdtd lattices ) and the theory of ordinary antennas , antennas based on photonic bandgap ( pbg ) materials and meta - materials are studied in the present dissertation 在开展有限时域差分法(结合各向异性完全匹配层边界)算法研究和普通天线模拟设计研究的工作基础上，本论文主要进行了基于光子晶体( pbg )与异向介质的新型天线的研究。
The radiation pattern of the antenna is more rotationally symmetric , and a more reduction on the sidelobe levels of the antenna is achieved as compared to the antenna with the corrugated soft surface . in conclusion , in the present thesis both theoretical and experimental research works have been carried out intensively on patch antennas based on photonic - bandgap structures . it is shown that our photonic bandgap structures can greatly improve the performance of the patch antennas 该平面圆环结构软表面天线是在空气介质的皱褶圆环结构软表面天线的基础上改进得到，为了便于比较，我们首先研究了空气介质的皱褶圆环结构软表面天线，用fdtd方法并结合pml吸收边界条件对该天线的性能进行了研究，结果表明天线的带宽增加，天线的轴对称性得到了很大改善， e面和h面方向图的波束几乎重合，天线的旁瓣和背瓣受到很大的抑制。
The results indicate that the transformation of transmission mechanism can be achieved when the tir - pcfs are filled with nlc . moreover , utilizing the difference of characteristics of modes in the pbgs , we achieve the shifting of pbg and model dispersion by modulating the refractive index of filled material based on pbg theory . further , tunable photonic bandgap fibers are proposed and demonstrated 基于光子带隙理论利用光纤传导模式在带隙内外传导模式的损耗、色散等特性的差异,我们首次提出并设计了通过外界物理量调节包层中填充介质的折射率,改变光子带隙和传导模式的色散曲线的相对位置,从而改变传导模式的损耗和色散等特性,最终得到了可调谐光子带隙光纤。
