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题名	稀土掺杂氟化铅激光晶体生长及性能研究
作者	尹继刚
学位类别	博士
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	氟化物晶体 晶体生长 光谱性能 激光性能
其他题名	Study on the growth and performance of rare earth ions doped lead fluoride laser crystals
中文摘要	高功率全固态激光器是激光器发展的一个重要方向。立方结构氟化铅晶体由于具备性能稳定、光学各向同性、低声子能量和容易实现大尺寸生长等优点，能够使激光器在大平均功率下工作，因而有望成为高功率大能量固体激光器理想的基质材料。Yb3+具有不存在激发态吸收、无上转换、可实现高掺杂浓度、量子效率高和荧光寿命长等优点；Tm3+发射的2μm激光在军事、通信、医疗和激光雷达等方面均有重要应用；因此Yb3+和Tm3+掺杂的立方结构的氟化铅晶体将有望成为高功率大能量固体激光器重要的激光增益介质，因此对其生长及各种性能的研究尤为重要。本文系统研究了稀土掺杂（镱和铥）立方结构氟化铅激光晶体的生长、光谱与激光性能。主要包括如下几个方面的内容： 第一部分：氟化铅及铥掺杂氟化铅晶体的生长及性能的研究 1.通过分析各个工艺参数（温度梯度、生长速度）和生长条件（除氧剂含量）对晶体生长的影响，成功生长出直径为30 mm透明完整的PbF2晶体，通过XRD、SEM、XPS和化学腐蚀等方法对得到的PbF2晶体进行了相应的质量分析，实验结果表明，用该方法生长出的PbF2晶体具有较高的光学质量，晶体的杂质元素（Pt、C和O）含量很少，不影响晶体在光学方面的应用。 2.对得到纯PbF2晶体的物理性质（密度、比热、热扩散系数和热导率）进行了实验研究，在晶体的热学性质上得到了与参考文献很大差别的实验结果(即室温下纯PbF2晶体的热导率仅为3.15 W/m•K)。首先通过理论推导总结出了适用于大量绝缘晶体材料热导率计算的公式，并通过对大量的不同结构的晶体热导率的计算结果与实验结果的比较，证明了该公式的准确和有效性后，对PbF2晶体进行计算并得到了与实验值很接近的结构(室温下纯PbF2晶体的热导率为4 W/m•K)。通过分析得出，PbF2晶体由于具有较小的德拜温度(仅为CaF2晶体的一半)，所以其具有较小的热导率，而并没有参考文献中介绍的那样优异。通过对PbF2晶体拉曼光谱的测量，确定了其声子能量的范围和最大的声子能量。 3.成功生长出Tm(2mol%): PbF2晶体，晶体的双晶摇摆曲线半高宽为108", XRD实验结果表明Tm3+的掺入没有改变PbF2基质晶体结构，但使得晶格常数和晶胞体积比纯PbF2晶体略有减小。同时还系统分析了Tm:PbF2晶体中填隙氟离子对Tm离子电荷补偿的方式和在晶体中对称结构。 4.根据J-O理论进算了Tm离子在PbF2晶体的中强度参数Ω2，4，6及振子强度fJ,J''、自发辐射跃迁几率AJ,J''、辐射寿命rad和荧光分支比J。并对Tm:PbF2晶体荧光光谱和荧光寿命进行了表征，对晶体中的自吸收现象进行了合理的解释。在Tm:PbF2晶体中首次实现了激光输出，当激光二极管泵浦功率为8.5W时，获得1.17W的连续激光输出，斜率效率为23%。 第二部分：镱和钠(钾)共掺氟化铅晶体的研究 1.成功生长出Yb:PbF2晶体，并对Yb:PbF2晶体的热学性能进行了系统研究，从理论上分析了掺杂对PbF2晶体热导率的影响。Yb:PbF2晶体的紫外吸收和荧光光谱的实验结果表明在Yb单掺的PbF2晶体中，Yb2+离子不可避免，PbF2晶体在可见波段较强的荧光是源自Yb3+离子与原料中的Tm3+和Er3+的杂质离子的上转换，而并非Yb3+离子的团簇发光。 2.生长了不同掺杂浓度的Na(K),Yb:PbF2晶体，首先研究了Na(K)离子共掺对Yb:PbF2晶体结构的影响，XPS的实验结果表明Na(K)离子共掺可以有效的抑制填隙氟离子在Yb:PbF2晶体中的浓度。晶体的紫外吸收、荧光光谱，实验结果表明Na(K)离子共掺可以有效的抑制Yb2+离子在晶体中的浓度，而Na离子的效果要优于K离子的。 3.系统研究了Na,Yb:PbF2晶体中Na和Yb离子不同摩尔比共掺对Yb离子的影响，实验结果表明通过调节Na和Yb离子的摩尔比，可以改变Yb离子在近红外波段的吸收和荧光光谱的谱带宽度和形状，并从理论上给予了相应的解释。同时还发现随着Na和Yb离子的摩尔比的增加，Yb离子的荧光寿命也不断增加。通过对相同掺杂浓度Na(K),Yb:PbF2晶体的光谱和激光参数对比发现，Na(2 mol%),Yb(2 mol%):PbF2晶体的综合性能最优越。 4.研究了温度对Na,Yb:PbF2晶体在近红外波段吸收、荧光和寿命的影响，借助低温的光谱，给出了Yb离子在Na,Yb:PbF2晶体中的能级分裂情况。 5.对不用掺杂浓度的Na,Yb:PbF2晶体进行了激光实验，976nmLD泵浦作用下获得了输出功率高达2.65W，中心波长在1045nm的激光输出，斜效率高达41%。采用单棱镜进行光谱调谐实验， 获得了从1017nm到1078nm的调谐激光输出。 关键词：氟化物晶体；晶体生长；光谱性能；激光性能
英文摘要	High power and large energy solid state laser is important for the development of lasers. Due to their merits such as stable performance, big rigidity, optical isotropy and high thermal conductivity, etc., which allow laser devices to work under big average power, fluoride crystals with cubic structure are usually the better choice as host materials apllied in high power and large energy solid state laser devices. Yb3+ has many attractive characteristics including no excited state absorption and upconversion loss, high doping concentration, high quantum efficiency and long radiative lifetime of the upper laser level. 2μm laser which emitted by Tm3+ has important applications in military, communication, medical therapy and laser radar. So Yb3+ and Tm3+ ion doped these crystals are important laser-active media for high power and large energy solid state lasers, and the study on the crystal growth and performance characterization of these crystals is necessary, especially for PbF2 crystals with cubic structure. In this thesis, we studied growth, spectral and laser performance of Tm and Yb ions doped PbF2 crystals. Results are described as follows: Part One: Study on the PbF2 and Tm doped PbF2 crystals. 1. Through the analysis of various process parameters (temperature gradient, growth rate) and growth conditions (oxygen agent content) to the influence of crystal growth, grow a success for 30 mm in diameter PbF2 complete transparent crystal, by XRD, SEM, XPS and chemical corrosion and other methods to get PbF2 crystal the corresponding quality analysis, the experimental results show that, with the method of crystal growth out PbF2 high optical quality, crystal of impurity element (Pt, C and O) content rarely, do not affect crystals in optical applications. 2. To get the physical properties of pure PbF2 crystals (density and heat capacity, thermal diffusion coefficient and thermal conductivity) the study the thermal properties of pure PbF2 crystals are a big difference with references to our experimental results (that is pure PbF2 crystal at room temperature of the thermal conductivity of just 3.15 W/m•K). First through the theory is summarized for bulk insulation crystal materials thermal conductivity calculation formula, and through to a lot of different structure of the crystal of the thermal conductivity calculation results and experimental results, it is demonstrated that the formula of the accurate and effectiveness after, to PbF2 crystal is calculated and obtained and compared with the experimental value is very close to the structure (room temperature PbF2 pure crystal of thermal conductivity is 4 W/m•K). Through the analysis, the conclusion PbF2 crystal because it has a small DE worship temperature (only for CaF2 crystal half), so it has the smaller thermal conductivity, and didn''t references as excellent introduction. Through to Raman of the PbF2 crystal spectroscopy measurement, confirmed the phonons energy range and the largest phonon energy. 3. Success grows out of Tm (2 mol%) : PbF2 crystals, crystal of FWHM is 108 ", XRD experimental results show that Tm3+ mixed not change PbF2 matrix, but makes the crystalline structure of the crystal lattice constant cell volume than pure PbF2 crystals. And at the same time decrease slightly system analysis the Tm: PbF2 crystals interstitial fluorin ion for Tm ion charge compensation and the way and in the crystal structure of the symmetrical. 4. According to J-O theory into calculate Tm ion in the PbF2 crystal of the strength parameters Ω2，4，6, oscillator strength fJ,J'', transition of the spontaneous radiation chance AJ,J, radiation rad rad, and fluorescence branch J. The fluorescence spectrum and fluorescence life of Tm: PbF2 crystal characterized, absorbing phenomena of crystals in since the reasonable interpretation. In Tm: PbF2 crystal first realized the laser output, when laser diode pumped power of 8.5 W, Tm: PbF2 crystal get 1.17 W continuous laser output, slope efficiency is 23%. Part Two: Study on the Yb doped PbF2 and Na, Yb co-doped PbF2 crystals. 1.Success grows out of Yb: PbF2 crystals, and Yb: PbF2 crystals of systemic research on the thermal properties, theoretically the doping PbF2 crystal to the influence of thermal conductivity. The ultraviolet absorption and fluorescence spectrum of the experimental results show that the Yb2+ ion is inevitable in the PbF2 , in the visible spectrum strong fluorescence in PbF2 crystals is derived from Yb3+ ions and Tm3+ and Er3+ impurity ions of the conversion in the raw material, and not Yb3+ ion clusters to shine. 2.The different growth doping concentration of Na(K), Yb:PbF2 crystal, first studied Na(K) ion were mixed on Yb:PbF2 crystal structure, the influence of the XPS experimental results show that Na(K) ion were mixed can restrain interstitial fluorin ion in Yb:PbF2 crystals in concentration. Crystal of ultraviolet absorption, fluorescence spectrum, the experimental results show that Na (K) ion were mixed can restrain Yb2+ ions in the crystals in concentration, and Na ion is superior to the effect of K ion. 3.The systematic study of the Na, Yb: PbF2 crystals Na and Yb ion different than the total of Yb with Moore ion influence, the experimental results show that by adjusting the Na and Yb ion the molar ratio of, can change Yb ion in near-infrared wavelengths of absorbing and fluorescence of the spectral bandwidth and shape, and the theoretical offers some explanation. It is also found that with Na and Yb ion of the molar ratio increases, Yb ion of fluorescent life is on the increase. Through the same for doping concentration Na (K), Yb: PbF2 crystal of spectrum and laser parameters that contrast, Na (2 mol %), Yb (2 mol %): PbF2 crystal the comprehensive performance of the most superior. 4.The research of temperature on the Na, Yb: PbF2 crystals in near-infrared wavelengths absorption, fluorescence, and the influence of the life, with the aid of the spectrum of low temperature, and gives the Yb ion in Na, Yb: PbF2 crystals in the energy-level splitting. 5. Without the doping concentration of Na,Yb:PbF2 crystal on the laser experiments, 976 nm LD pump function gained power output as high as 2.65 W, center in 1045 nm wavelength of the laser output, the efficiency is as high as 41%. The single prism spectral tuned experiment, won the 1017 nm to 1078 nm from the tuning laser output. Key words: PbF2 crystal; Crystal growth; Spectral properties; Laser performance
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15683]
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	尹继刚. 稀土掺杂氟化铅激光晶体生长及性能研究[D]. 中国科学院上海光学精密机械研究所. 2012.

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