Preparation And Properties Of The Fluorinated Polyimide Polymer Optical Waveguide

As the basic structure of integrated optics, any kind of waveguide has been receiving much research in many cases. In many materials for fabricating waveguides, macromolecule polymers are focused on research due to their advantages which are low transmission loss, high thermo-optic coefficient, low thermal conductivity, and high heat resistance. So the fluorinated polyimide optics waveguide with rigid link and Semi-flexible link is fabricated on Quartz glass. The main contents of the thesis are as follows.First of all, the model theory of thin-film waveguide is detailed derived, and the way of surveying thickness and the refractive index is prism coupling. And furth-ermore, a series of processes of preparing and testing waveguide are systematically introduced, and it mainly consist of cleaning the substrate, compounding fluorinated polyimide solution, spinning coating, annealing and testing and so on.Second of all, rigid fluorinated polyimide thin film containing the solute ODA,6FDA and PMDA is fabricated in the first part of this article, and the Semi-flexible fluorinated thin film containing the solute ODA,6FDA and BTDA is fabricated in the second part this article. And through many experiments of this thesis, the main effecting factor are annealing temperature, F-ion concentration, time of annealing and the rate of spinning coating. Moreover, the relation between waveguide’s properties and process factor is obtained. F-ion concentration, annealing temperature, time of annealing mainly affect the refractive index and the rate of spinning coating mainly affect the thickness of thin film. After thermal imidization, the reason of refractive index trends in the following temperature is due to different solute molecular structure and different mixing ratio,and then there is a linear relationship between F-ion concentration and refractive index, however, before thermal imidization there is not such relationship. Shortening the annealing time may improve the temperature of completing thermal imidization. After a series of experiment the formula is found between the rate of spinning coating and thickness of thin film. Last, Spinning coating four times on Quartz glass by the way of piling up multi-layer structure is used to obtain a kind of waveguide which has smooth surface as well as thick thickness. This method not only reduce the scattering loss but also make different thicknesses to meet different needs.