A 4.8-W M^2 = 4.6 Continuous-Wave Intracavity Sum-Frequency Diode-Pumped Solid-State Yellow Laser

A yellow continuous wave with beam quality M^2= 4.6 and output power of 4.8 W at 589nm is generated by intracavity sum-frequency mixing of 1064 nm and 1319 nm radiations of a Nd：YAG laser. To achieve high beam quality at high power, thermally near-unstable flat-flat resonators with two-rod birefringence compensation are designed to obtain the large fundamental mode size inside the Nd：YAG rods and the same beam width inside the KTP crystal. The optimal intracavity power ratio of both 1064nm and 1319nm beams is also considered. The output power fluctuation of the yellow laser remains less than 5% in four hours.     

YAG：Ce^3＋荧光粉的合成及α-Al2O3籽晶对相形成的促进作用

用聚丙烯酰胺凝胶法来合成YAG：Ge^3＋荧光粉，用XRD对煅烧过程粉体的结构进行了跟踪测定。结果发现，当直接煅烧凝胶时，可观察到θ-Al2O3，YAM和YAP等中间相的形成，而当煅烧含有α-Al2O3，YAM和YAP的形成，加速其与Y203的反应而在较低温度下直接生成YAG相。合成YAG：Ce^3＋荧光粉的发射峰为处于550nm的宽峰，其激发光谱有两个主要的吸收峰，主峰位于460nm，可以与GaN LED的蓝色发射相匹配而用于白光LED的组装。一些助熔剂可以提高荧光粉的光致发光特性，这归因于助熔剂对YAG结晶过程的改进作用和对YAG：Ce^3＋中三价铈离子的稳定作用。     

掺杂型BaFBr:Eu2+的热释发光性质的研究

BaFBr:Eu^2 是利用色心存储电子－空穴对并用可见光激励读出存储信息（产生Eu^2 的4f^65d→4f^7的跃迁）的优良的光激励发光材料。通过热释发光技术研究了BaFBr:Eu^2 的热激活行为，对其低温段和高温段的热释发光峰分别进行了归属，通过对BaFBr:Eu^2 以及掺杂Na^ 或Al^3 的BaFBr:Eu^2 的热释发光（TL）谱和光激励发光（PSL）谱的表征，指出在BaFBr:Eu^2 中掺杂Na^ 或Al^3 影响了F（Br^-）色心，使其陷阱深度变涛，并从理论上加以计算，得出的热致激发能量的变化与光致激光能量的变化能很好地吻合。     

液体相位共轭技术应用于高重复频率双通放大器实验

固体激光器运转过程中工作物质的热效应严重地影响着激光器的输出光束质量，20世纪60年代末Ostcrink等从理论和实验上研究了Nd：YAG晶体产生的热效应，相位共轭镜技术能够补偿热效应造成的波前畸变，从而改善了激光器的光束质量。液体相位共轭镜大多数采用了CS2、丙酮、CCL4、SnCL4、HPLCll3（氟里昂）等液体，由于丙酮液体的相对污染少，SBS阈值功率密度低，且市场上容易购买，因而得到普遍运用。文中报道了在重复频率400Hz，脉宽20ns的二极管泵浦Nd：YAG双通放大激光器中用丙酮液体作为相位共轭镜改善光束质量的实验研究。激光器SBS实验光路采用聚焦光斑在液体池里扫描和不扫描两种方式。     

Yb：YAG晶体的热学性质及其对激光性能的影响

对于中频感应加热提拉法（Czochralski Method)生长的高掺杂浓度（原子数分数0.30)Yb:YAG晶体，经退火后采用差示扫描量热计法测量了晶体的比热容，通过激光脉冲法测量了不同掺杂浓度（原子数分数0.05-0.30Yb:YAG晶体的热扩散率和热导率。实验表明，随着Yb^3 离子浓度增加，Yb:YAG晶体在300K温度下的导热性能有明显的降低。原子数分数为0.30的Yb:YAG晶体的激光实验表明，高掺杂浓度Yb:YAG晶体热导率的降低导致了激光阈值的增加。     

Orientation-Enhanced Photorefractive Effect in PVK-PBA：DR1：TNF Polymer

We developed a novel photorefractive (PR) polymer PVK-PBA:DR1:TNF, and its film sample was prepared with outstanding performance by using the method of combination of vacuum saturated vapour resolving with vacuum hot-pressing. The sample exhibits distinctive PR properties with the two-beam coupling coefficient up to 140cm^-1 and four-wave mixing (FWM) diffraction efficiency above 1.5% in the absence of applied external electric field. The designed experiments, including measurements of the second-order nonlinear coefficient and birefringence as well as the relationship between the diffraction efficiencies of the FWM and the external bias field, were performed to understand the underlying mechanism, because this phenomenon cannot be explained by the conventional PR theories. It is presented that because of its high orientational mobility and large dipole moment, the polymer produces the photovoltaic effect under the irradiation of laser to induce a space-charge field so as to engender the PR effect under zero or low external fields. A model based on the assumption was established and the simulation agrees well with the experimental results.     

CsI：T1转换屏的发光灵敏度研究

转换屏在辐射照相系统中具有很重要的作用，它的效率影响整个系统的性能。本文对透明的具有较大厚度的CsI：T1转换屏的效率进行了详细的分析，推导了其效率的表达形式，并得到了实验的证明。     

锗酸镉中镨的长余辉发光特性

通过高温固相法在空气条件下制得cd2Ge7016：Pr3’长余辉发光材料。测其结构为一单相。分析了cd2Ge70…cd2Ge7016：Pr3’的激发光谱和发射光谱，指出Cd2Ge7016：Pr3’的发光是Cd2Ge7016本身和Pr3’离子发射产生，基质的发光是Cd2Ge70．6中有陷阱能级，电子从导带跃迁到陷阱能级而产生，Pr3’的发光是该离子的4f一4f跃迁产生的；并把该材料的长余辉性质归结为基质结构中有电子陷阱和空穴陷阱，电子陷阱和空穴陷阱分别能储存电子和空穴，从而产生余辉。并提出余辉机理模型。     

450W二极管泵浦Nd：YAG薄片激光器

二极管泵浦高平均功率固体激光器在工业、科研和军事等领域具有非常广泛的应用。光学泵浦将在固体激光介质里产生废热并引起介质温度升高。激光器的连续运转要求实时冷却以消除废热。由于固体激光介质的热导率通常较低，因此在激光介质内部和冷却表面之间将产生显著的温度梯度，这就导致了折射率梯度、机械应力和退偏等效应，进而降低光束质量，减小输出功率，甚至造成介质的断裂。这些效应是固体激光器向高平均功率定标的最大挑战。采用薄片激光介质是解决这一问题的有效手段之一。