Yb：GdVO₄系列激光晶体的生长及其性能研究

【作者】 于永贵；

【导师】 王继扬； 张怀金；

【作者基本信息】 山东大学 ， 材料学， 2006， 硕士

【摘要】 由于将半导体和固体激光器相结合，激光二极管（LD）泵浦的固体激光器（DPSSL）将两者的优点结合到一起：具有体积小、寿命长、全固化、泵浦效率高、输出稳定等优点，被广泛应用于军事、医疗、光通讯、材料加工、激光测距和激光核聚变等领域。激光工作物质作为DPSSL的重要组成部分是设计全固态激光器的关键因素，并决定着激光器的性能及其应用价值，因而，探索性能优异的激光材料成为研究全固态激光器的热点之一。 钒酸盐系列晶体被证明是性能优良的激光工作物质。其中，研究最多的是Nd：YVO₄、Nd：GdVO₄和Nd：LuVO₄。在中小功率中，Nd：YVO₄是应用最为成功的一种。而相对于YVO₄具有更高热导率的GdVO₄晶体，则在高功率应用中占有优势。同属三价稀土离子的Yb³⁺也因其自身特点，使得Yb³⁺激光器在若干应用上将明显优于Nd³⁺激光器。目前对掺Yb³⁺钒酸盐晶体的研究还不是很多，也不很全面，因此，有必要开展对Yb：GdVO₄晶体的研究工作。 本论文对Yb：GdVO₄晶体的生长、结构、缺陷、热学性质、光谱性质及激光性能进行了系统的研究，主要包括以下几个方面的工作： 一、晶体生长 以纯度为99.99％的V₂O₅、Yb₂O₃和Gd₂O₃通过液相反应合成出晶体生长所需要的多晶料。采用提拉法及选取适当的生长工艺生长出不同掺杂浓度的Yb：GdVO₄晶体。讨论了生长工艺参数、温场、固液界面等因素对晶体生长的影响以及提高晶体质量的途径与方法。 二、结构测定 分析了晶体的结构与生长形貌。用X射线荧光法测量了晶体中Yb³⁺，Gd³⁺和V⁵⁺离子的分凝系数，结果表明Yb³⁺离子的分凝系数与Nd：GdVO₄晶体中Nd³⁺离子的分凝系数相差不大，Yb³⁺离子可进行较高浓度的掺杂。通过X-ray粉末衍射法测定了Yb：GdVO₄晶体的结构、计算了晶胞参数，为四方晶系，I4₁／amd空间群，晶胞参数随Yb³⁺离子掺杂浓度的增加而减小。高分辨X射线衍射实验对晶体的单晶性进行了检验。锥光干涉图表明Yb：GdVO₄晶体为单轴晶。更多还原

【Abstract】 Merging with both the strongpoints of semiconductor and solid-state lasers, Diode-pumped Solid-state Lasers （DPSSL） have been widely used in the fields of military, medical treatment, optical communication, material processing, laser measurement, etc, due to its advantages such as compactness, long lifetime, all-solid state, high efficiency and high stability. Searching for more efficient laser crystals has become a hotpoint since such materials play important roles both in laser designing and laser application.Single crystals of rare earth orthovanadate （ReVO₄） including Nd:YVO₄, Nd:GdVO₄ and Nd:LuVO₄ have been proved to be excellent laser materials. Nd:YVO₄ crystal has been commercialized in small-medium-power laser systems, while GdVO₄ crystal, with high thermal conductivity, is a promising material in high power laser application. Lasers based on Yb³⁺ -doped materials have some advantages over those based on Nd³⁺ ion. However, studies on Yb:ReVO₄ crystals such as Yb:GdVO₄ are scarce by far, so it is necessary to carry out research work on this promising laser material.In this work, crystal growth, structure, defects, thermal and spectral properties together with laser performance have been systematically investigated, the outline is shown as follows:1. Crystal growthPolycrystalline material for Yb:GdVO₄ single crystal growth was synthesized by a liquid-phase reaction method and the starting reagents were V₂O₅, Yb₂O₃ and Gd₂O₃ with a purity of 99.99%. Deferent doping concentration of Yb:GdVO₄ crystals were grown by the Czochraski method, and influence on crystal growth and quality apposed by such factors as growth parameters, thermal environment and the growth interface were discussed.2. Structure analysisThe structure and growth morphology of Yb:GdVO₄ crystal were analyzed.更多还原