Study On Nanostructure Formation And Third-order Optical Nonlinearities Of Gold Doped Chalcogenide Glasses

With the approaching of information age, the development of all optical switch with high-speed has become a hotspot of communication materials. In the influence of thrid-order nonlinear optical properties of optoelectronic materials, the refractive index changed nonlinearly by the effect of ultrafast femtosecond laser pulse, as to realize the process of optical switch.Third-order nonlinear properties material played the most important fact for this behavior, so many studies on different optical materials were conducted to develop thrid-order nonlinear materials with high performance. Chalcogenide glasses have attracted extensive attention and research because of their unique optical and semiconductor properties. They had advantages of good chemical stability and thermal stability in the most transparent band, excellent optical damage threshold, fast nonlinear response time et al, and the most important merit was their high third-order nonlinear coefficient, so that chalcogenide glasses had a very broad application prospect and potential.The purpose of this paper was to develop optcial materials with high third-order nonlinear coefficient. Through measuring and data analysis, the oxide glasses were studied to find excellent mechanical properties, but their uniformity and nonlinearity were in an inferior position to chalcogenide glasses. Then, the work was focused to develop chalcogenide glass with high third-order nonlinear coefficients.The paper described the production process of glass and the measurement of glass performanc. It included the thermal stability analysis, the absorption and transform data analysis, measurement and calculation of Z scanning, and the glass structure analysis method. Bi2O3-Ge O2-Ba O(BGB) oxide glasses were prepared to discover that after Ba was doped, glass density and refractive index decreased, while Raman scattering intensity showed a contrary tendency. By analysing the Raman scattering spectra, the evolution of glass structures was presented. Two groups of Ge Sb S glass were prepared by using the clear identification of cause and effect to change one factor. The GSS matrix of chalcogenide glass were studied by this method. The Ge-Sb and Sb2S3 bonds played important roles in the glass structure.Ga10Ge25S65(GGS) chalcogenide glass doped with various amounts of gold were prepared. Both density and refractive index showed an increase trend with the increasing of gold content. Raman spectra informed that the main vibration modes of the glasses came from [Ge S4] tetrahedra, gold was a glass modifier for the GGS glasses. Z-scan measurements were employed to discover that the third-order optical nonlinearity of glasses were improved with addition of gold. Transparent chalcogenide glass ceramics were prepared by thermally treating gold-doped germanium-gallium-sulfur glass. The gold ions, as nucleating agents, modified the crystallization process of the glass, resulting in the formation of nanocrystals belonging to a single α-Ga2S3 phase. Z-scan measurements revealed the performance improvement of the α-Ga2S3 nanocrystals to third-order optical nonlinearities.We concluded all results of the present work and pointed out some shortages which should be improved in the future at last.