Preparation And Optical Properties Of New Erbium-doped Optical Materials And Optical Waveguide Studies

The EDWAs (Erbium Doped Waveguide Amplifiers) are important optical elements. They will play key roles in the development of FTTH (Fiber To The Home) technology in future, Fabrication of EDWAs has become a hot subject in photonics. Several different and competing techniques have been developed to prepare EDWAs. Therefor investigation on erbium doped materials, EDWA fabrication techniques, and optical properties of various kinds of erbium doped materials and EDWA are part of the most basic and important research fields.This Ph.D thesis reports on research works in the subject of "The study of novel erbium doped optics materials, waveguides preparing, and their optical properties". The research works included: preparing bulk erbium doped sol-gel glass materials and erbium doped planar optical waveguides by sol-gel technique, the study of organic complexes of erbium and their fluorescence properties, and writing optical waveguides in erbium doped silicate glasses by the femtosecond laser pulses. Three open questions were paid more attentions. They are the fluorescence quenching problem of the erbium doped xerogel samples due to the residual hydroxyl groups, the problem of the very low fluorescence quantum efficiencies of the erbium organic complexes, and the physical mechanism of writing optical waveguides in glasses by femtosecond laser pulses. The main results of the research works are as follows:1. The erbium doped bulk sol-gel glass samples with good optical quality were prepared. Annealing the samples in CCl₄/O₂ atmosphere was used as the chemical dehydration process. The 1.55 μm fluorescence lifetimes of these samples were as long as 6.2 ms, which was one of the longest results for the bulk sol-gel glasses as we know. And the mechanism in the dehydration process was discussed.2. Six erbium organic complexes were designed and synthesized. Their fluorescence properties were measured and compared. The results showed that both the OH and CH groups in the complexes could quench the erbium ions heavily. Since the CH groups exist in almost all the organic materials, it should be a key factor to be responsible for the low quantum efficiency. Moreover, Er(perfluorooctylate)3, a novel organic complex of erbium which contains neither OH nor CH groups was obtained for the first time. Its quantum yield was found to be as high as 1%, 100 times higher than that ever reported. The result takes a great step for the application of the erbium doped organic materials.