Study On Preparation And Nonlinear Optical Properties Of Sb₂S₃ Doped Sol-gel-derived Silica Glasses

Due to the potential application in the optical communication field, nonlinearoptical glasses, as one of nonlinear materials, have attracted great attention in fields ofresearch and application. As one type of nonlinear optical glasses, crystallite dopedglasses also attract people' sight due to great second and third order nonlinear opticalsusceptibility. According to the previous research, the material with high refractiveindex is helpful to enhance the nonlinear properties. Therefore, a fundamentalresearch on sol-gel preparation and non-linear optical properties of Sb₂S₃ doped silicaglasses was made in this thesis.With the analysis methods of TG-DSC, XRD and HRTEM, the process ofpreparation is systematically conducted. Utilizing the UV-Vis-NIR spectra, PL spectra,OKE and Maker fringe methods, nonlinear properties of these glasses were studied.Main conclusions are as follows:Firstly, the Sb₂S₃ crystallite doped silica glasses has been prepared. Themaximum of the dopant in the glasses is up to 6wt%. The crystallite size in the glassesis about 2～5nm and increases with increasing heat treatment time and temperature.Secondly, the UV cut-off edge of glass shifts towards short wavelength with thedecreasing size of crystallite which shows the quantum size effect. The fluorescence isobserved in the PL spectra. The intensity decreases and the peaks of PL spectra shifttowards long wavelength with increasing heat treatment temperature and time.Thirdly, third order optical nonlinearity is observed in the Sb₂S₃ crystallite dopedsilica glasses. The response time and third order nonlinearity is 260fs and3.848×10^-13esu, respectively, which is ascribed to combination of the intrabandtransition in the semiconductor crystallite and localized charge effect.Lastly, after thermal poling and electron beam irradiation, Maker fringe pattern isobserved and the maximum is around±50～60°of incidence degrees. The optimumtemperature is 170℃during thermal poling. The SH intensity has great dependenceon the irradiation conditions and the size of crystallites. After irradiation, the SHintensity can decrease with delay. The maxiumum of second order nonlinearitysusceptibility is up to 2.21pm/V. The depth of poling domain is under the surface ofthe sample about 10μm after irradiation.