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题名	镁钕/铥双掺钽酸锂晶体的生长与性能研究
作者	弓娟
学位类别	硕士
答辩日期	2012
授予单位	中国科学院上海光学精密机械研究所
导师	杭寅
关键词	钽酸锂晶体 提拉法 光损伤 光学性能 激光自倍频
其他题名	Studies on the growth and properties of Mg and Nd/Tm co-doped in the LiTaO3 Crystals
中文摘要	钽酸锂（LiTaO3，简称LT）晶体作为性能优良的多功能晶体，被广泛地应用于声表面波、电光、声光、集成电子、信息存储等方面。随着准相位匹配技术的发展，在钽酸锂晶体中掺杂稀土离子以实现激光自倍频输出，是钽酸锂晶体的重要发展方向之一。研究表明，掺杂Mg可以提高钽酸锂晶体质量，尤其在光损伤方面能大幅提高晶体的抗损能力。将Mg与稀土离子双掺，旨在获得高质量自倍频激光晶体。 本文主要内容包括以下几个方面： （1） 详细记述了提拉法生长 Nd,Mg:LT 晶体的工艺过程，包括配制原料、混 料、烧料、晶体生长、极化等工艺参数，并成功生长出了1%Nd:LT、1%Nd,2%Mg:LT、1%Nd,3%Mg:LT、1%Nd,4%Mg:LT和0.5%Tm,4%Mg:LT晶体。 （2） 使用X-射线粉末衍射实验对Nd,Mg:LT系列晶体和0.5%Tm,4%Mg:LT晶体进行分析，结果表明晶体结晶度非常好，掺杂并没有改变晶体的结构。结合锂空位模型，分析晶胞参数的变化，我们认为单掺晶体中掺杂离子占位主要以锂空位 或反位钽 为主，形成 ；而双掺晶体中Mg2+离子优先进入锂空位 或反位钽 ，形成 ，同时Nd3+离子进入正常Ta5+位，形成 ，在LT晶体内部形成 - - 结构。 （3） 使用红外透射谱对Nd,Mg:LT系列晶体进行了分析，结果表明随着Mg掺杂的升高，LT晶体在3500cm-1左右的峰位发生了轻微的红移，分析后认为是掺杂取代位置变化引起的，随低浓度掺杂时杂质优先取代反位钽，随着掺杂浓度的升高逐渐取代正常Ta、Li位。 （4） 使用拉曼光谱对Nd,Mg:LT系列晶体进行了分析，结果表明随着掺杂浓度的升高，与锂空位相关的振动模式消失，占位规律与红外透射谱一致。 （5） 对Nd,Mg:LT系列晶体和0.5%Tm,4%Mg:LT晶体的吸收谱、荧光谱、荧光寿命等进行了测试与分析，进行了光谱参数计算，并评估了 LT 晶体作为激光基质以及在激光自倍频方面的应用前景。 （6） 使用光斑形变法对Nd,Mg:LT系列晶体的抗光损伤能力进行了判定，结果表明随着Mg掺杂浓度的提高，晶体的抗损伤阈值也随之提高。 （7） 对1%Nd,2%Mg:LT晶体进行了激光实验，实现了斜率效率为22%的激光输出。并通过连续输出和调Q输出两种方式进行了分析。
英文摘要	As the excellent performance in multi-function, Lithium tantalate ( LiTaO3, LT ) has been used in surface acoustic wave, electro-optic, acousto-optic, integrated electronic, holographic storage and so on. Along with the development in quasi-phase matching method, the LT crystal has been the potential self-frequency-doubled generation laser host with doped rare earth. This is one of the most important research development directions for LT crystals. At the same time, studies show that Mg-doped LT crystals can significantly improve their performance in photodamage aspects. So co-doped in the crystals, aim at getting high quality self-frequency-doubled laser crystals. In this paper, Nd,Mg:LT crystals and 0.5%Tm,4%Mg:LT crystal were successfully grown by Czochralski method. Their structures and properties were studied by a variety of methods. The research work is summarized as the following: (1) The growth process of Nd,Mg:LT crystals and 0.5%Tm,4%Mg:LT crystal were detailed recorded, including raw matetial preparation, crystal growth and poling process. 1%Nd:LT、1%Nd,2%Mg:LT、1%Nd,3%Mg:LT、1%Nd,4%Mg:LT、0.5%Tm,4%Mg:LT were successfully grown by Czochralski method. (2) XRD results indicated a very good crystallization of the crystals. The doped ions in the crystals resulted a little change in lattice parameters, the crystals still remain their own structure. (3) Infrared absorption spectra of Nd,Mg:LT crystals were measured. The result indicated that with the increasing of Mg doped, the peak in 3500cm-1 appeared a slight red shift, which was caused by the changing of the doped position. (4) Micro-Raman spectra of Nd,Mg:LT crystals were also measured. The result indicated that with the increasing of Mg doped, some Li-vacant related mode disappeared. This phenomenon prsented the same trend with the infrared absorption spectra. Basised on the Li-vacant model, we discussed the doped ions’ locations in LT crystals. (5) The absorption spectra, fluoeresence spectra and lifetime of Nd,Mg:LT crystals and 0.5%Tm,4%Mg:LT crystal were measured, and the optical parameters of Tm3+ were calculated by J-O theory. Furthermore, we assessed the LT crystal’s potential applications in self-frequency-doubled laser hosts and devices. (6) Photodamage resistance thresholds of the crystals were obtained by laser damage test. The result indicated that doped-Mg could increase the photodamage resistance thresholds of the crystals. (7) Under LD pumping with 2.19W, we got 126mW output power in 1%Nd,2%Mg:LT crystal.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16705]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	弓娟. 镁钕/铥双掺钽酸锂晶体的生长与性能研究[D]. 中国科学院上海光学精密机械研究所. 2012.

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