| Lithium niobate (LiNbO3, LN) crystal is one of the most promising synthetic materials, Since it has goog electro-optic, acousto-optic, thermal-optic, ferroelectric, piezoelectric and photorefractive properties. It is considered as a major contender for the role of "optical silicon". At present, a main breakthrough of the optical damage resistance in lithium niobate is the tetravalent dopents. It has been reported that hafnium and Zirconium are new elements with high resistance to photorefraction.In this dissertation, we investigate the peoperties tetravalent tin doped Lithium niobate crystal.Chapter one introduces the basic physical properties of lithium niobate crystals and give a brief overview of it's defect structure.Chapter two, we introduce the conventional Czochralski method and grow LN:Sn series crystals along the c axis. With 1.0,2.0,2.5,3.0,4.0 and 5.0 mol% SnO2 added into the melt.Chapter three, the experimental results show that the optical damange threshold of LiNbO3:Sn crystal is about 3×105W/cm2; the threshold concentration of doped Sn is about 2.5 mol%; and near the threshold value,the distribution coefficient is 0.98.Chapter four, we investigate the UV photorefractive properties of LiNbO3 doubl doped with Fe and Sn. The diffraction efficiency of LiNbO3:Fe:Sn can reach as high as 70% while the response time is shortened to 1.12s. LiNbO3:Fe:Sn is a good candidate for holographic storage.Chapter five, we summarize this dissertation and give an outlook for further studies in this field.
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