Yb∶Y3Al5O12晶体晶格振动光谱的研究

采用提拉法生长Y3Al5O12(YAG)晶体和Yb3+掺杂原子数分数分别为5%, 10%, 15%, 20%, 25%, 50%和100%的Yb∶Y3Al5O12(Yb∶YAG)晶体。系统表征和分析了Yb3+掺杂浓度对拉曼光谱的影响。随着Yb3+掺杂浓度的增加,晶体的振动模式没有明显的变化,晶体结构没有改变;在370 cm-1和785 cm-1附近,振动吸收峰的半峰全宽逐渐增大。分析得出,Yb3+掺杂浓度对晶体的晶格、对称性、荧光寿命均有影响,从而可能影响到晶体的光谱和激光性能。

掺Yb^3＋氧化镧钇透明激光陶瓷的光谱特性

采用传统陶瓷烧结工艺,在无压还原气氛下低温制备出透明性良好的掺Yb^3＋氧化镧钇透明激光陶瓷,测试了其在室温下的吸收光谱、发射光谱和荧光寿命.结果表明,掺Yb^3＋氧化镧钇透明激光陶瓷的吸收系数随着Yb^3＋掺杂浓度的增加而增大,最强吸收峰974 nm处的吸收截面为0.90～1.12×10^-20 cm^2;主发射峰1 032 nm和1 075 nm处的发射截面分别为1.05×10^-20 cm^2和0.87×10^-20 cm^2; Yb^3＋掺杂浓度为5at.%时荧光寿命为1.38 ms,并随Yb^3

Spectroscopic properties of Yb:YAP crystal

The 10at% Yb-YAP crystal has been grown by the Czochralski method. The absorption and emission spectra and fluorescence lifetime of Yb:YAP crystal at room temperature were studied. There is a strong absorption band centered at 959 nm and the absorption cross-section of 1.51 × 10^-20 cm². The emission cross-section at 1040 nm is 0.6 × 10^-20 cm² and the fluorescence lifetime is about 1.2 ms. The effects of O₂-annealing on the spectral properties were studied. The spectroscopic properties strongly depended on the axis direction and b axis was the best direction for laser output. The spectrum parameters of Yb:YAP and Yb:YAG crystal were compared.}

Yb：YAG透明陶瓷的制备和激光输出

制备了高质量的Yb：YAG透明陶瓷．Yb：YAG透明陶瓷的晶粒尺寸为10μm左右且分布均匀，晶界处和晶粒中没有杂质、气孔的存在．Yb：YAG样品中所有元素分布均匀，不同的晶粒间，晶粒和晶界间成分是一致的，没有出现成分的偏析．4mm厚样品的透过率为80％．LD泵浦获得了波长为1030nm，最大功率为268mW的连续激光输出．

Er^3＋／Yb^3＋共掺的氧化镧钇透明陶瓷的光谱性能研究

采用传统无压烧结工艺制备了Er^3＋／Yb^3＋共掺的氧化镧钇透明陶瓷并对其光谱性能进行了研究．样品具有较大的吸收和发射截面．La2O3的添加使样品的荧光寿命（τs）与玻璃接近，当Yb^3＋和Er^3＋的掺杂量分别为5at％和0．5at％时，测得τs=9．65ms．这种荧光寿命长、发射截面大和线宽窄的特性有利于微型、可集成化和大功率激光输出的实现．

共掺Na^＋的Yb^3＋：CaF2晶体的荧光分析与低阈值激光运转

基于975nm激发的室温下荧光光谱测量，系统地研究了在新型钠、镱共掺的氟化钙晶体中钠离子的作用机理，分析了掺钠离子浓度与激光阈值的关系，获得了具有最低激光阈值的掺杂浓度优化配比．激光实验表明对于2％Yb^3＋离子浓度的氟化钙，掺入3％的钠离子能够获得最低阈值的激光运转，这与理论和荧光分析完全一致．

La2O3对Yb：Y2O3透明陶瓷光谱性能的影响

研究了La2O3对Yb：Y2O3透明陶瓷光谱性能的影响，添加适量La2O3以后，Yb：Y2O3透明陶瓷的吸收峰和发射峰的位置不变，但由于La^3＋的离子半径大于Y^3＋的离子半径，在Y2O3中引入La^3＋离子后，导致Y2O3晶格常数变大，晶场强度变弱，同时降低了Y2O3晶体的有序度，致使发射峰强度有所下降，发射截面变小．过量的№La2O3（x=0．16）造成yb^3＋激活离子发射强度明显下降；其荧光寿命在添加La2O3后总体增大45％-60％.

国产Yb∶YAG透明陶瓷实现激光输出

YAG单晶是高功率激光的重要材料，近年来高透明度多晶陶瓷作为激光介质引起人们广泛的注意。YAG陶瓷相对单晶具有易制造大尺寸、掺杂浓度高、易批量生产等优点。在Nd：YAG陶瓷获得长足发展的同时，Yb掺杂的陶瓷也得到了越来越多的关注。Yb：YAG陶瓷与Nd：YAG陶瓷相比具有许多优点：Yb掺杂的激光介质无交叉弛豫振荡和激发态吸收，有较宽的吸收带，较长的荧光寿命及较高的量子效率等。因此，高质量的Yb：YAG陶瓷将是非常理想的高功率激光材料。

Yb:YAP与Yb:YAG晶体光谱性能比较

应用中频感应提拉法生长出掺杂浓度为10 at.-%的Yb:YAG与Yb:YAP晶体，对比了室温下两种晶体的吸收和发射光谱特性。结果表明，Yb:YAG晶体比Yb:YAP晶体有更好的激光性能和低的阈值；同时对比发现，Yb:YAP晶体的吸收截面是Yb:YAG晶体的2.16倍，它容易实现LD泵；由于Yb:YAP晶体的各向异性，它有轴向效应明显，它可以产生偏振激光。

Yb∶Y_3Al_5O_(12)/Y_3Al_5O_(12)复合晶体的制作和光谱性能

采用热键合技术,制作中运用不同的工艺参量制作出12片Yb∶Y3Al5O12/Y3Al5O12(Yb∶YAG/YAG)复合晶体。利用偏光显微镜对其键合界面进行了观察,研究了样品的透射光谱,从而确定出复合晶体合适的制作工艺。通过透射光谱的形状和透射率来表征复合晶体键合界面的质量。研究表明Yb∶YAG/YAG复合晶体键合质量较好,可实现一体化。

Effects of gamma-irradiation and air annealing on Yb-doped Y3Al5O12 single crystal

The effects of gamma-irradiation on the air-annealed 10 at.% Yb:Y3Al5O12 (YAG) and air annealing on the gamma-irradiated 10at.% Yb:YAG have been studied by the difference absorption spectra before and after treatment. The gamma-irradiation and air annealing led to opposite changes of the absorption properties of the Yb:YAG crystal. After air annealing, the gamma-irradiation induced centers were totally removed and the concentration of Fe3+ and Yb3+ were lightly increased. For the first time, the gamma-irradiation induced valence changes between Yb3+ and Yb2+ ions in Yb:YAG crystals have been observed. (C) 2007 Elsevier B.V. All rights reserved.

Growth and spectral properties of Yb,Tm:YAG crystal

The YAG crystal codoped with Yb3+ and Tm3+ has been grown by Czochralski (Cz) method. The crystal structure of the crystal has been determined by X-ray diffraction analysis. The absorption and emission spectra of Yb,Tm:YAG crystal at room temperature have also been studied. The emission cross-sections have been calculated by Fuechtbauer-Ladenburg formula and reciprocity method. (C) 2007 Elsevier B.V. All rights reserved.

Luminescence characteristics of Yb3+, La3+ codoped yttrium oxide nanopowders

Luminescence characteristics of Yb3+, La3+ codoped yttrium oxide nanopowders were investigated. The grain size and the crystallinity of (Yb0.05Y0.90La0.05)(2)O-3 nanopowders increase with the increase of calcination temperature. The average grain size of the nanopowders calcined at 1100 degrees C is 66 nm and its cooperative up-conversion luminescence centered at 498 nm was detected due to nanometer size effect and perfect crystallinity. However, the cooperative up-conversion luminescence of (Yb0.05Y0.90La0.05)(2)O-3 transparent ceramics was not detected. (c) 2008 Elsevier B.V. All rights reserved.

Bonding quality of Yb : Y3Al5O12/Y3Al5O12 composite crystals

The Yb:Y3Al5O12/Y3Al5O12 (Yb:YAG/YAG) composite crystals were prepared by thermal bonding method with different technological parameters. The bonding interface of the composite crystals were observed by optical microscope, scanning electron microscope, and atom force microscope. The light scattering experiments for bonding interface of the composite crystals were measured by the laser and transmission spectra. All experiments show that high-quality Yb:YAG/YAG composite crystals without space transition layer and light scattering on the bonding interface can be obtained by thermal bonding method under appropriate technological parameters.

Spectral investigation of Yb-doped calcium pyroniobate crystal

Ytterbium-doped calcium pyroniobate single crystal has been grown for the first time. Spectral properties of Yb: Ca2Nb2O7 were investigated by emission and absorption spectra. Its cooperative luminescence and fluorescence lifetime were also studied. Yb ions in Ca2Nb2O7 showed very broad absorption and emission bandwidth and relatively large absorption and emission cross-sections. Along with other optical properties, this Yb-doped crystal would be a potential self-frequency doubling femtosecond laser gain material. (C) 2007 Published by Elsevier B.V.