Study On Preparation And Second Harmonic Generation Of Nanosized Sb₂S₃ Doped PMMA/TEOS Glasses Made By The Sol-gel Process

Due to the potential application in the optical communication,nonlinear optical glasses,as one of nonlinear materials,have been studied for many years.As one kind of nonlinear optical glasses,crystallite doped glasses was also studied due to its big second and third order nonlinear optical susceptibility.According to the previous researches,the materials with high refractive index will own better nonlinear properties.Therefore,a fundamental study on sol-gel preparation and nonlinear optical properties of Sb₂S₃ doped PMMA/SiO₂ glasses was performed in this paper.Organic-inorganic hybrid materials became one of promising materials due to its applications in many fields such as mechanics,thermodynamics,optics, electromagnetism,chemistry and biology.With the advantages of mild reaction conditions and multiplex synthesis routines,Sol-gel method has greatly facilitated the manufacture of PMMA/SiO₂ hybrid materials.However,two serious shortcomings must be overcome in preparing bulky hybrid materials:1.Due to the poor miscibility of the two phases,the macroscopic phase separation easily occurs,and thus deteriorate the performances of the materials.2.The volume shrinkage during the preparing processes is inevitable, which makes the shape and size controlling of the materials difficult.In this paper,MMA and TEOS as the primer materials are selected to produce low shrinkage,high light performance bulky PMMA/SiO₂ hybrid material.Sb₂S₃ is introduced into the hybrid material by sol-gel method.In order to reduce the possible volume shrinkage,a method have been adopted:minimizing the quantity of water as possible in TEOS hydrolyzing,pre-polymerization the organic monomers,mixing inorganic pre-cursors and pre-polymerized organic monomers under a non-co-solvent condition and the small molecular species are removed with annealing.Furthermore, in order to improve the miscibility of the organic and inorganic species,one type of silane coupling agent(KH-570)which hydrolyzed simultaneously with TEOS has been introduced into the system.With the measurements of TG-DSC,XRD and HRTEM,the process of preparation is systematically conducted.Utilizing the PL spectra,the Maker fringe methods,nonlinear properties of these glasses were studied.Main conclusions were obtained as follows:The Sb₂S₃ crystallite doped PMMA/SiO₂ glasses have been prepared.The maximum of the dopant in the glasses was up to 9wt%.The crystallite size in the glasses increased with the increasing of annealing time.After electron beam irradiation,Maker fringe pattern was observed and the maximum value was obtained around±50～60°of incidence degrees.The Second Harmonic(SH)intensity was strongly related to the irradiation conditions and the size of crystallites.After irradiation,the SH intensity decreased.The maximum of second order nonlinearity susceptibility was up to 1.64pm/V.The depth of poling domain was under the surface of the sample about 10μm after irradiation.