【作者】 陈淑文；

【导师】 方安安； 丁杰；

【作者基本信息】 南昌大学 ， 电子与通信工程， 2011， 硕士

【摘要】 本论文的主要研究内容如下：1.首先,利用转移矩阵的方法详细研究了基于杂质带的光子晶体矩形波形滤波器,通过选择不同的折射率材料、或调整光子晶体本身的结构参数,都可获得光子晶体矩形波形滤波器。论文对较平杂质带形成的物理机制也做了详细的分析和理论解释,数值计算光子晶体原子逐步耦合成光子晶体分子所得的结果,发现它们两者线宽之间的相对大小是决定能否形成平坦杂质带的关键,杂质带的形成的物理图像非常清晰。光通信中群速度的延迟,将直接导致超短脉冲信号的失真或者衰减,从这个意义上来说,获得相对平坦的杂质带对光通信中超短脉冲的不失真传输非常重要。2.设计了一种五光子晶体单模波导平行、邻近放置构成的光通信中的定向耦合器,按照自映像的原理,数值计算了输入光场在对称入射时,光信号在该结构中的传输行为。基于此结构,设计了一种1×3光通信中的光分束器,其器件长度可低至14.26μm。简单地通过对称改变耦合区中两个介质柱的折射率,由于位相的变化,干涉结果也将发生变化,这样便可使光场在横向上发生重新分布,输出端输出能量均分或者自由地分配的目的就能实现。如果非对称地改变耦合区中的一个介质柱,三个输出端输出能量的自由分配也能实现。该分束器具有微小尺寸和各输出端输出能量的比例可自由调制的特性,在未来集成光通信回路中无疑具有广泛的应用价值。更多还原

【Abstract】 The main research contents of this dissertation are as follows:1. Firstly, the realization of rectangular wave filter based on the photonic crystals impurity band has been investigated by means of transfer matrix method. The formation of the quasi-flat bands can be achieved not only by choosing different materials with different refractive indexes but also by adjusting the structure parameters of photonic crystal(PC) itself. So the realization has a large choice range. The dissertation gives a detailed theory analysis and explanation about the rectangular wave formation mechanism. The processing when two PC atoms(signal defect) are coupled to form a PC molecule(two coupled defects) is analyzed in detail. It is found that the ratio of the PC atom linewidth to the PC molecule linewidth plays an important role in the forming of quasi-flat bands. The physical picture about the rectangular wave is also clearly illustrated in this article.Group velocity delay in optical communication will directly lead to ultra-short pulse signal distortion or attenuation. From this perspective, obtaining a relatively quasi-flat bands is very important for the ultra-short transportation without any distortion in optical communication.2. Directional coupler in optical communication can be constructed by putting five photonic crystal waveguides together. The propagation of the optical field entering this system symmetrically is analyzed numerically on the basis of self-imaging principle.1×3 beam splitter, which the length can lowly be 14.26μm. is designed by using this structure. By symmetrically tuning the effective refractive index of two dielectric rods in the coupler, accordingly inducing the redistribution of the electric field, uniform or free energy split can be achieved. By asymmetrically tuning the effective refractive index of one dielectric rod in the coupler, free energy split can also be achieved.Due to the ultracompact size and the free energy split of the output power, the device has extensive practical value in future optical communication photonic integrated circuits.更多还原