光子晶体波导特性及其应用的研究

【作者】 李雷；

【导师】 肖峻；

【作者基本信息】 电子科技大学 ， 光学工程， 2011， 硕士

【摘要】 光子晶体是一种介电常数周期性分布的人工介质材料,其最主要的两大特征是具有光子带隙和光子局域,可以利用光子晶体的这两个特征来控制光的传输。在完整的光子晶体中,引入点缺陷可以形成光子晶体微腔,引入线缺陷可以形成光子晶体波导。光子晶体的周期在光波长量级。光子晶体波导不同于传统光波导,其最主要的优点是在大的拐角处可以实现低损耗甚至零损耗传输。这一优点使得光子晶体波导更加容易集成,在集成光学中有重要应用。本论文的主要研究工作如下:1.分析了二维光子晶体带隙的成因以及影响二维光子晶体带隙的因素,这些因素主要包括介质柱形状,介质柱的半径(填充率),相对折射率以及晶格结构。2.运用多模干涉的自映像原理,研究了光子晶体波导的耦合特性。采用平面波展开法计算了光子晶体波导的色散曲线,为分析光子晶体定向耦合器提供了基础,采用有限时域差分法模拟了定向耦合器中稳态光波场的分布。分析了二平行光子晶体波导的耦合以及解耦合特性、三平行光子晶体波导的耦合以及解耦和。3.基于多模干涉的自映像原理提出并优化设计了一种实用的光子晶体器件——光子晶体波导1×2光分束器。研究表明,优化后的分束器的结构,其对1.55μm波长的入射光,分束器的透射率高达93%,与没有引入介质柱的结构相比分束器的透射率提高了18个百分点。更多还原

【Abstract】 Photonic crystals are artificial dielectric materials which dielectric constant changes periodically, and its two most important features are photonic band gap and photon localization. The propagation of the light can be controll using the two features of the photonic crystal. Photonic crystal microcavity can be constructed by introducing a point defect, and photonic crystal waveguide can be constructed by introducing a line defect. The period of the photonic crystal is the same scale with optical wavelength. It’s different from traditional optical waveguide in that a low even zero loss of energy transport can be realized photonic crystal waveguide with sharp bends. This is the greatest advantage of photonic crystal waveguide. The advantage makes it easier to be integrated. Therefore, photonic crystal waveguide have important applications in the field of integrated optics.The main research works are as following:1. The causes of the two-dimensional (2-D) photonic crystal band gap and the factors that affect the 2-D photonic band gap are all studied.The main factors include the shape of the dielectric rod, the radius of the dielectric rod, relative refractive index and lattice structure.2. On the basis of self-imaging principle of multimode interference, the coupling feature of photonic crystal waveguide is studied. The photonic crystal waveguide dispersion curve is derived using the plane wave expansion method, which is convinent for the analysis of photonic crystal directional coupler. The light field distribution of the steady state in the directional coupler is simulated using the method of the finite difference time domain. The two parallel photonic crystal waveguides’coupling and decoupling properties are analyzed, and the three parallel photonic crystal waveguides’coupling and decoupling properties are also analyzed.3. Based on self-imaging principle of multimode interference, a practical photonic crystal device—1×2 beam splitter is proposed and is optimized. The optimized structure has a very high transmissivity, as high as 93% for the 1.55μm, the transmissivity is improved 18 percentage points compared to the dielectric rod is not introduced.更多还原