【作者】 曾四化；

【导师】 朱大庆； 刘劲松；

【作者基本信息】 华中科技大学 ， 物理电子学， 2004， 硕士

【摘要】 集成光学是随着现代信息处理系统的发展而产生的,它提供了具有不同集成度及不同功能的集成光路,从而弥补了传统的光学信息系统的缺陷。光衰减器是一种广泛应用的无源光器件。结合高分子聚合物自身的性能优势,研究聚合物波导型可调光衰减器有着非常重要的意义。本文的主要工作就是围绕聚合物可调光衰减器展开的,主要讨论了光衰减器的工作原理,设计优化方法以及工艺因素的影响,具体的内容如下:首先介绍了集成光波导器件产生,发展和器件材料工艺的进展,同时介绍了光衰减器的作用及现阶段国内外公司的相关产品性能,提出了本课题的研究目的和内容。然后是介绍了目前光衰减器的各种实现方法的原理,主要介绍了位移型,光衰减片型,液晶型,微机电系统型以及热光波导型的衰减器,并对热光波导型光衰减器的工作原理——热光效应和热传导做了较为全面的理论介绍分析。接着介绍了用于模拟计算的有限差分光束传播法FD-BPM(Finite Difference-Beam Propagation Method)方法的基本原理及算法的稳定性分析,及求解的透明边界条件,同时介绍了将三维结构转化为二维结构的有效折射率法,并且用这些方法模拟了Y分支的特性。然后是详细的介绍了一种非对称的Y分支型光衰减器的设计优化过程。先根据前文介绍的热传导理论模拟了用于可调衰减器的电极的热场分布,设计了电极的最优位置,然后利用马卡蒂里近似解法求解掩埋条形波导的单模条件,并计算了波导的宽度和厚度,设计了非对称Y分支型的光衰减器的Y分支结构,电极参数,完成整个设计过程,最后,模拟了光衰减器的偏振相关性和波长相关性,从而也得到了一个聚合物可调光衰减器的设计优化方法。最后,考虑了旋涂法成膜及光刻对器件形成造成的宏观误差,模拟了薄膜厚度,波导宽度和Y分支角钝角给器件性能带来的影响。本文提出了一种集成光波导器件的数值模拟设计及优化方法,对其他的集成光波导器件的设计有着指导参考价值。更多还原

【Abstract】 Integrated optics emerges with the development of modern information process system. It can offer integrated optical circuit with different functions to meet the new requirements for optical process system. Optical attenuator is a kind of widely used passive optical component. Recently material used to fabricate waveguide components has achieved considerable development. Among them, polymer has attracted great attention due to its superior characteristics such as low power consumption and easy to fabricate, etc. In this thesis, focusing on polymeric variable optical attenuator, the main content is as follows:Firstly, the development of integrated waveguide components and its fabrication method was introduced, and the function of attenuator was also described. Secondly, the principles of different kinds of optical attenuator were introduced , including type of mechanical-shift,optical attenuator glasses, liquid crystal, micro-electro-mechanical systems(MEMS) and thermo-optical waveguide. Then the basis of thermo-optical attenuator—thermo-optic effect and heat conduction was specially discussed.Thirdly, FD-BPM(Finite Difference-Beam Propagation Method),the method to simulate the variable optical attenuator was introduced. The reliability and its TBC(Transparent Boundary Condition) were also concerned. EIM(Efficient Index Method) was then analyzed which is used to transfer a 3-D waveguide to 2-D waveguide and simplify the simulation.Fourthly, a detailed process to design and optimize a variable optical attenuator was researched. Based on the theory of heat conduction, the heater thermal field was calculated to determine the most efficient position of heater. And the parameters of heater and asymmetric Y branch were decided using FD-BPM method. After the design and optimization, the polarization dependence and wavelength dependence of the attenuator were researched.Finally, the effect of spin coating polymer film error to the attenuator was simulated. Three kinds of errors were considered, which were film thickness, waveguides width and angle of Y branch. This thesis put forward a method to design and simulate a kind of waveguide component and will help to design other integrated waveguide components.更多还原