光子晶体论文：光子晶体中光传输特性的理论研究.doc

光子晶体论文：光子晶体中光传输特性的理论研究【中文摘要】本论文基于国家自然科学基金资助课题“无序介质激光机理的相关研究”及“单光子激光的新机理研究”的工作基础上,围绕光子晶体的光传输特性,分别对正负折射率交替变化的一维光子晶体的透射谱,一维三元光子晶体微腔的模式竞争特性进行了研究,深入探讨了二维三角晶格光子晶体点缺陷的光子局域化,以及光子晶体波导的耦合特性,论文主要内容包括：1、光子晶体的研究现状及其理论方法介绍。2、基于传输矩阵法(TMM)理论,研究了折射率正负交替光子晶体正入射时,介质层数目和光学厚度随机对光波传输特性的影响,并计算透射谱以及介质层内光场的分布。结果表明：光子晶体的传输特性与随机度和介质层的厚度相关,透射率随介质层厚度随机度的增大而降低,带宽变窄；透过率随介质层数增大而减小,禁带宽度却变得更宽；介质层内光场呈现局域状态。3、利用传输矩阵理论研究了一维三元光子晶体带增益介质微腔的传输特性,结果表明：透射谱呈现出模式竞争特性；发现透射主峰的中心波长和Zno增益介质层厚度互相匹配。在其他参数合适的情况下,改变Zno增益介质层厚度,透射主峰的中心波长也相应改变。另外,增大光子晶体介质层数目或增大泵浦光强度,模式竞争现象更加明显。4、通过平面波展开法对二维点缺陷三角晶格光子晶体的微腔结构进行研究,计算得出其色散图以及缺陷模分布。结果表明：缺陷模波长与微腔谐振波长基本吻合。利用FDTD模拟谐振波长波段的电磁波在光子晶体中传播的动态演化过程,并计算出局域模的空间分布图。最后在有规律地改变缺陷周围介质柱半径的情况下实现谐振中心波长的可调性。5、提出一种基于光子晶体耦合波导实现光开关效应的方法：将线缺陷引入二维光子晶体以形成两平行的邻近波导,两邻近波导及其中间的两排介质柱构成了光开关模型耦合区；利用平面波展开法计算了不同介质填充率情况下的色散特性曲线。结果发现；减小介质填充率可以实现波导耦合长度的减小；分段调整中间介质柱的填充率和选择不同的耦合搭配长度,定向耦合器内的光波可以与任意分段介质进行独立、互不相干地耦合,光信号可以在两耦合波导中进行受控地、不间断地交替传输,从而实现了光信号沿两不同端口受控输出的开关效应。国家自然科学基金(批准号：60768001,60278016)资助课题【英文摘要】This thesis is based on the National National Science Foundation of China “a relevant study of the new mechanism on lasing in random media” and “ single photo laser”, around the optical transmission properties of photonic crystals,many problems about photonic crystals are studied,such as study of optical properties of a random photonic crystal with NIM-PIM alternant multilayer, the characteristics of mode competition in the micro-cavity of one-demensional ternary photonic crystals, study the micro-cavity structure of the two-dimensional triangular lattice photonic crystal with defects, demonstrate a novel optical switching structure based on a coupled photonic crystal waveguides.The key points of this thesis are presented as follows:1.The introduction of photonic crystals about the research situation and theory method.2. Study the influences from the number of plies of the medium and the thickness to the transmission characteristics of the light by using the design procedure of transmission matrix and the light field distribution in dielectric layer, when the photonic crystals are negative refractive index alternating incident. The results shows that the transmission characteristics of photonic crystals is related to the random degree and the thickness of the dielectric layer. Then we can find that the bandwidth becomes narrow when the transmittivity reduces with the thickness of the dielectric layer is increased, v.v. Finally, in the dielectric layer, the light appear the local states.3. We present the characteristics of mode competition with gain medium in the micro-cavity of one-demensional ternary photonic crystal with transfer matrix method. From the results, we know that the transmission spectra have the characteristics of mode competition. And then, we also know the central wavelength of the peak transmission and the thickness of the Zno gain medium are matching. In the case of other parameters are appropriate,if we change the thickness of the thickness of the Zno gain medium, the central wavelength of the peak transmission will also be changed. Others if we increase the number of the dielectric layer of photonic crystal or increase the intensity of pumping light, the mode competition will be more pronounced.4. In this paper,we study the micro-cavity structure of the two-dimensional triangular lattice photonic crystal with defects by plane wave expansion method.We can calculate dispersion curves and the distribution of defect mode. Results showed that the wave of the defect mode is consistent with the wavelength of the micro-cavity resonant wave. We simulated the dynamic propagating process in the photonic crystal about electromagnetic wave of the resonant wavelength band by using of the FDTD method, we can figure out the graph of the local modes space distribution. Finally, we will carry out the tuneable property of the centralwavelength of the resonant wave by using the method of regularly changing the radius of dielectric cylinder around the defect.5. In this paper,we demonstrate a novel optical switching structure based on a coupled photonic crystal waveguides。The switching structure is formed by two closely spaced linear defect waveguides in a two-dimensional photonic crystal of air holes in semiconductor matrix.We investigate fill factor which affects dispersion diagram by using PWM methods. In the coupling region,we found that the input signal beam can be controlled by choosing a appropriate coupling length for exchanging singals between two output ports.The coupling efficiency is increased and the coupling length is also reduced by modifying the fill factor of the coupling region between the coupled waveguides【关键词】光子晶体 传输矩阵法 时域有限差分法 光子晶体波导【英文关键词】photonic crystal transfer matrix method finite difference time domain photonic crystal coupled waveguides【目录】光子晶体中光传输特性的理论研究摘要3-5ABSTRACT5-6目录7-9第一章 绪论9-141.1 光子晶体简介91.2 光子晶体的结构及特性9-111.3 光子晶体的应用11-121.4 本文的主要内容12-14第二章 光子晶体的研究理论14-272.1 平面波展开法142.2 多重散射法142.3 N阶法14-152.4 传输矩阵法15-202.4.1 单一介质层的传输矩阵15-192.4.2 一维多层介质的传输矩阵192.4.3 透射系数和反射系数19-202.4.4 介质层中光场的分布202.5 时域有限差分法20-262.5.1 无源场的麦克斯韦方程20-212.5.2 三维空间的FDTD形式21-232.5.3 二维平面的FDTD形式23-252.5.4 数值稳定条件252.5.5 PML吸收边界条件25-262.6 本章小结26-27第三章 折射率正负交替的随机光子晶体的传输特性27-353.1 模型和计算方法27-283.2 数值计算与讨论28-343.3 本章小结34-35第四章 一维三元光子晶体微腔中模式竞争特性35-444