【作者】 张学建；

【导师】 刘景和；

【作者基本信息】 长春理工大学 ， 材料物理与化学， 2009， 博士

【摘要】 激光材料与元器件是激光技术发展的核心和基础,具有里程碑的作用和意义。世界上第一台激光器诞生于1960年,半个世纪以来,激光技术得到迅速发展,现已广泛应用于战术激光武器(硬杀伤、软杀伤)、激光制导、激光测距、激光通讯、先进制造技术(激光加工、激光焊接)、激光医疗、激光显示等各个领域,并进入高速发展期,将造就二十一世纪的支柱产业,世界各主要国家均将其作为国家战略高技术发展计划。目前,激光器技术向着一泵(LD)、两高(高功率、高能量)、三化(小型化、智能化、集成化)、三超(超短、超快、超强)方向发展,而激光材料是激光技术发展的核心和先导。因此,激光材料在高新领域将拥有规模巨大的激光及元器件应用市场需求。Yb:YAG激光材料(晶体、陶瓷),具有优良的物理与光学特性,吸收峰(941nm)靠近发射峰(1030nm),具有低的量子缺陷和宽的泵浦吸收带；电子结构简单,没有受激态吸收、上转换或浓度猝灭；荧光寿命长,储能比Nd:YAG高；它产生的百分比热量几乎比Nd:YAG增益介质低4倍,被证明在所有介质中它产生的热效应最小。实践证明,激光性能、可靠性和成本等方面都明显优于Nd:YAG激光基质材料。本文对Yb:YAG晶体生长、陶瓷制备及性能进行了系统的研究。(1)提出了低真空充保护气氛的新工艺,采用中频感应加热提拉法,设计合理的温场,选择最佳工艺参数,生长了Φ20-35mm×40-100mmYb:YAG激光晶体。(2)采用XRD、TG-DTA、吸收光谱、荧光光谱等测试技术,对Yb:YAG晶体的性能进行了研究。同时,还对晶体缺陷进行了系统的分析与讨论。(3)首次提出一次性退火工艺,给出了最佳的退火工艺参数,研究了一次退火和二次退火工艺对晶体质量的影响。(4)对尺寸为Φ3mm×10mmYb:YAG晶体消光比进行了研究,消光比为48.6dB。对Φ3mm×10mm激光元件进行了光学均匀性测试,干涉条纹≤0.095条／25mm,达到了国内先进水平。(5)采用3mm×8mm×1mmYb:YAG激光微片,分别利用绿光输出镜和黄光输出镜实现1030nm波长室温运转,结果表明采用黄光输出镜时,激光性能较好。在泵浦功率为2W时,阈值功率为189 mW,输出功率为152.5mW实际功率为213.5 mW。光—光转换效率为11.79%,斜效率为11.87%。(6)采用2mm×2mm×10mmYb:YAG激光微片,研究Yb:YAG晶体的倍频激光性能。结果表明：使用绿光出镜时,激光性能较优。阈值功率为461mW,输出功率为72.27mW,因此实际输出功率为101.18 mW。光—光转化效率为6.57%,斜效率为7.02%。(7)采用溶胶—凝胶法(sol-gel)和碳酸盐共沉淀法,合成了Yb:YAG激光陶瓷粉体,探讨了反应机理及影响因素。利用TG-DTA、XRD、IR、TEM及光谱分析等测试手段,研究了粉体的结构、形貌及光谱性能等。(8)通过前驱体的煅烧、成型和烧结等工艺过程,制备高性能的Yb:YAG陶瓷材料,并通过一系列的测试表征对制备的样品进行结构分析,得出它们的微观结构信息,并对影响透明陶瓷的因素和激光特性进行了深入地研究和分析。更多还原

【Abstract】 Laser materials and components are the core and foundation of the development of laser technology, which has the significance of milestone. The first laser in the world was born in 1960. During half a century, laser technology has been developed rapidly, and has been widely applied in tactical laser weapon (hard and soft killing damage), laser guidance, laser range finder, laser communications, advanced manufacturing technology (laser processing and laser welding), laser medical treatment, laser display fields and so on, and entered the high-speed developing period. It will make the pillar industry of 21st century. All the main countries take it as an national strategy high technology development plan.At present, laser technology has developed towards the direction to one pump (LD), two high (high power, high energy) and three more (more miniaturing, more intelligent, more integrating), three super (super short, super fast, super strong). In addition, laser materials are the core and forerunner of the development of laser technology. Therefore, laser material has the large scale of applied market demand on laser and components in high-tech fields.Yb:YAG laser materials (crystal and ceramic) have excellent physical and optical properties. The absorption peak (941nm) is close to the emission peak (1030nm), and have low quantum defects and wide pumping absorption bands. Its electronic structure is simple, having not excited state absorption, upconversion or concentration quenching. Moreover, it has longer fluorescence life and higher energy than Nd:YAG. The percent heat Yb:YAG generates can be four times lower than that of, and Yb:YAG has the least heat effect of all the mediumms. It is proved that Yb:YAG laser matrix materials are superior to Nd:YAG in aspects of laser performance, reliability and cost, etc.In this paper, the crystal growth, ceramic preparation and performance of Yb:YAG were studied systematically.(1). The new technics that is filling protective atmosphere in the lower vacuum has been presented firstly. According to designing reasonable temperature field and selecting the optimum technical parameters, the Yb:YAG laser crystal with a dimension ofΦ20-35mm×60-100mm was grown by Czochralski method to medium frequency induction heating.(2). The performance of Yb:YAG crystal were investigated by using several measurements, such as XRD, TG-DTA, absorption spectrum, fluorescence spectrum and so on. Meanwhile, the defects of Yb:YAG crystal were analyzed and discussed systematically.(3). The one-time annealing process has been presented firstly, and the optimum annealing technical parameters can be obtained. In addition, the influence of one-time and second-time annealing process on crystal quality was studied.(4). The extinction ratio of Yb:YAG crystal with a dimension ofΦ3mm×10mm was studied, and the extinction ratio is equal to 48.6dB. The optical uniformity of laser components was tested, and the interference fringes less than or equal to 0.095 article per 25mm, which has reached the international advanced level.(5). Using 3mm×8mm×1mmYb:YAG laser micro-chip, respectively, the use of green light and yellow light output mirror appearance to achieve room temperature operation of 1030nm wavelength, results show that the laser performance is better when the yellow light output mirror was used. The pumping power is 2W, the threshold power is 189 mW, the output power is up to 152.5mW, The real output power is equal to 213.5mW. Light-light conversion efficiency and slope efficiency is 11.79%,11.87%, respectively.(6). Using 2mm×2mm×10mmYb:YAG laser micro-chip,the Yb:YAG crystal frequency doubling laser performance was studied.The results showed that:in condition of the use of green light output mirror, the laser performance is better. Threshold power is 461mW, the output power and actual output power is 72.27mW,101.18 mW, respectively. Light-light conversion efficiency is up to 6.57%, slope efficiency is equal to 7.02%.(7). The laser ceramic powders were synthesized by using sol-gel and carbonate altogether precipitation methods, and reaction mechanism and influencing factors were discussed. The structure, morphology and spectral properties were studied by several measurements, such as TG-DTA, XRD, IR, TEM, spectral analysis and so on.(8). The Yb:YAG ceramic material of high quality was prepared through the technics of calcining, forming and sintering to precursor. The structures of prepared samples were analyzed through a series of measurements, and the microstructure of information was obtained. Moreover, the factors to affecting transparent ceramic and laser properties have been analyzed and studied deeply.更多还原