【作者】 张焱冰；

【导师】 曾晓雁；

【作者基本信息】 华中科技大学 ， 光学工程， 2009， 硕士

【摘要】 光波导是光器件的最基本结构单元,因此对光波导理论、波导材料的合成和波导的制备工艺开展研究具有十分重要的意义。氟化聚酰亚胺因其损耗低、折射率可调、热稳定性与机械性能好而被广泛用于制作条形光波导材料。本文利用含氟二胺和二酐合成了含氟聚酰亚胺光波导材料,并通过微笔直写工艺制备出了条形光波导。采用有限折射率法对条形波导进行了理论分析,利用BPM(光束传播方法)方法模拟了光能量的分布,计算出当波导下包层厚度大于3.5μm时,能有效的约束光的传输。由于微笔直写具有效率高、工艺简单、可以一次成型等优点,选择它作为条形光波导的制作工艺。通过“两步法”,利用含氟二胺与二酐,合成出了氟化聚酰亚胺材料,并对其相关性能进行了分析与表征。DSC和TGA分析表明,其玻璃化温度大约为380℃,起始分解温度大于480℃;通过改变含氟量,其折射率可以在1.521~1.672之间调节。将其中间产物聚酰胺酸配制成浓度为0.2g/ml的溶液,通过称重量的方法可以较定量地确定溶液的黏度。直写出了条形光波导,并对其形貌进行了分析。实验表明,直写施加气压(P)、微笔的平移速度(V)和微笔头到基板的高度(H)等工艺参数对波导形貌有较大影响。当聚酰胺酸与其配制的溶液抽黏后的质量比为4和3.7时,分别在V=4mm/s、P=9KPa、H=18μm和V=3mm/s、P=11KPa、H=20μm时,热固化后能得到宽高比分别约为11和5且形貌良好的条形波导。更多还原

【Abstract】 Optical waveguide is the basic unit of optical device. It is meaningful to study on the waveguide theory, synthesis of waveguide material, fabrication process of waveguide. Fluorinated polyimide has been widely applied to prepare strip optical waveguide because of its low absorption, controllable refractive index, high thermal stability and excellent mechanical properties. In this thesis, the fluorinated polyimide was synthesized from diamine and dianhydride, and the strip optical waveguide was fabricated through micropen direct-wring process.Theoretical analysis was conducted to the strip waveguide by the effective refractive index method, and the distribution of optical intensity was stimulated with BPM(Beam Propagation Method). It was calculated out that the optical field can be constrained in the strip waveguide only when the thickness of the undercoating was more than 3.5μm. The micropen direct-writing was applied to dispense strip waveguide owing to its high efficiency, simple process and rapid prototyping.Fluorinated polyimide was synthesized from diamine and dianhydride by two-step method, and its properties were characterized. Thermal analysis by DSC and TGA showed that its glass transition temperature was about 380℃and its starting decomposition temperature was higher than 480℃. The refractive index could be ranged by the content of fluorine from 1.521 to 1.672. The viscosity of polyamic acid solution could be relatively quantitated through weighing.The strip waveguide was fabricated and its shape was tested. Experiments demonstrated that the processing parameters such as the exerted gas pressure(P), velocity of micropen tip(V)and height from micropen to substrate(H)affected the shape of the dispensed waveguide. When the weight ratios of fluorinated polyimide to polyamic acid solution were 4 and 3.7, the optimal parameters were V=4mm/s, P=9KPa, H=18μm and V=3mm/s, P=11KPa, H=20μm, respectively. The shapes of the dispensed waveguides were perfect with the width/height ratios of approximately 11 and 5, respectively.更多还原