Ce:Cu:SBN晶体的生长及其自泵浦位相共轭效应的研究

在铌酸锶钡中掺入ＣｅＯ２和ＣｕＯ，生长了Ｃｅ：Ｃｕ：ＳＢＮ晶体，测试了该晶体的衍射效率、自泵浦位相共轭反射率和响应时间。以Ｃｅ：Ｃｕ：ＳＢＮ晶体作为自泵浦位相共轭镜，以Ｚｎ：Ｆｅ：ＬｉＮｂＯ３晶体作为存储介质，实现了实时关联存储。     

Ce：Cu：SBN晶体的生长及其光折变效应的研究

简述了Ｃｅ：Ｃｕ：ＳＢＮ晶体的生长,测试了晶体的衍射效率、简并四波混频位相共轭反射率和响应时间,以Ｚｎ：Ｆｅ：ＬｉＮｂＯ３晶体作为存储介质,以Ｃｅ：Ｃｕ：ＳＢＮ晶体作为自泵浦位相共轭镜,实现了实时关联存储。     

Ce：Eu：KNSBN晶体位相共轭效应的研究

在KNSBN晶体中掺进CeO2和Eu2O3,以硅钼棒作加热体,利用Czochralski法生长Ce:Eu:KNSBN晶体,测试18度切和0度切晶体的自泵浦位相共轭反射度和响应时间,18度切的样品自泵浦位相共轭性能位于0度切的样品,采用自泵浦位相共轭镜,In:Fe：LiNbO3晶体作为存储介质,实现了关联存储。     

钾钠铌酸锶钡系列晶体自泵浦位相共轭镜的研究

报道了钾钠铌酸锶（ＫＮＳＢＮ）晶体系列自泵浦位相共轭反射镜的最新研究结果。ＫＮＳＢＮ：Ｃｕ、ＫＮＳＢＮ：Ｃｏ和ＫＮＳＢＮ：Ｃｅ自泵浦位相共轭反射镜的反射率分别可达７３％、７３％和８４．３％，ＫＮＳＢＮ：Ｃｕ自泵浦位相共轭反射镜的响应时间在低功率下达２００ｍｓ。     

双掺杂LiNbO3晶体的生长及其实时图象微分的研究

采用Ｃｚｏｃｈｒａｌｓｋｉ Ｚｎ：Ｆｅ：ＬｎＮｂＯ３晶体和Ｃｅ：Ｎｄ：ＬｉＮｂＯ３晶体。测试了晶体的抗光致散射能力、衍射效率和响应时间。以双掺杂ＬｉＮｂＯ３晶体作为全息记录材料,Ｃｅ：Ｃｕ：ＫＮＳＢＮ晶体构成自泵浦位相共轭镜,进行了实时图象边缘增强的研究,并探讨了不同的记录晶体对实验结果的影响。     

Pr:Fe:LiNbO3晶体光折变性能的研究

在Fe∶LiNbO3中掺进Pr6011生长Pr∶Fe∶LiNbO3晶体。对晶体进行氧化－还原处理。测试晶体的指数增益系数、衍射效率、响应时间、光电导和信噪比。测试结果Pr∶Fe∶LiNbO3晶体的响应时间缩短,信噪比提高,克服了Fe∶LiNbO3响应时间长,光电导和信噪低的缺点。以Pr∶Fe∶LiNbO3晶体作为存储元件实现了全息关联存储。     

汽车零部件包装用PP/SBN复合材料的性能研究

目的 研究单层氮化硼（Single-layer Boron Nitride, SBN）对聚丙烯（Polypropylene, PP）力学性能和摩擦性能的影响。方法 首先利用超声剥离和硅烷偶联剂KH550表面改性方法制得SBN,用高速混合机将PP、马来酸酐接枝聚丙烯（PP-g-MAH）和SBN混合均匀;然后利用注塑机通过熔融共混,制备PP/SBN复合材料。结果 当SBN质量分数低于1.6%时,PP/SBN的表面硬度和耐磨性能得到了进一步改善;当SBN质量分数高于1.6%时,PP/SBN的力学强度和摩擦性能降低;当SBN质量分数为1.6%时,PP/SBN的拉伸强度和冲击强度分别达到最大值（35.27 MPa, 34.69 kJ/m2）,较纯PP分别提高了10.7%, 18.8%。此时,PP/SBN的摩擦因数和磨损率较纯PP分别降低了15.1%, 32.4%。结论 当SBN质量分数为1.6%时,对PP具有增强增韧作用,复合材料的力学性能和耐磨性能都得到明显提高。     

提拉法Tm:YAG晶体的生长缺陷研究

采用提拉法(CZ)生长了质量优异的Tm:YAG晶体.部分晶片在1000℃的空气气氛中退火25h.借助光学显微镜、扫描电子显微镜(SEM),结合化学腐蚀法,对Tm:YAG晶体退火前后(111)面的缺陷特征进行了研究. Tm:YAG晶体(111)面的位错腐蚀坑呈三角形. 在偏光显微镜下观察了退火前后Tm:YAG晶体(111)面的应力双折射.同时应用高分辨X射线衍射法测定了晶体的完整性.实验结果表明,长时间空气气氛下高温退火有效降低了晶体中总的位错密度,提高了晶体质量.     

前驱体凝胶法制备SrxBa1-xNb2O6铁电薄膜的研究

以羟基羧酸作为配位剂与金属离子配位,以乙二醇为交联剂促进聚合反应并以碳酸盐为反应原料,采用前躯体凝胶法在水溶液中制备铌酸锶钡(SrxBa1-xNb2O6,SBN)前驱体溶胶.将此溶胶在预热的Si/SiO2/Ti/Pt基片上旋转涂膜得到了平整均匀的SBN铁电薄膜.研究了pH值、乙二醇(EG)/柠檬酸(CA)(质量比)、热处理温度对SBN凝胶相组成、相结构以及SBN薄膜形貌的影响规律.结果表明当pH≥7且EG:CA=60:40时,可以获得稳定性良好的溶胶.对SBN薄膜热处理和红外光谱分析表明:随温度升高,SBN相衍射峰逐渐增强,晶型转变明显.同时COO-基团也逐渐消失,Sr-O、Ba-O和Nb-O峰显著增强.在800℃时,可得到单一钨青铜相的铌酸锶钡;SBN薄膜的SEM微观组织表明在750℃退火条件下可以获得晶粒为纳米级的表面均匀、无裂纹的SBN薄膜.     

铌酸锶钡薄膜制备及椭偏光谱研究

用溶胶-凝胶法成功地制备出了退火温度分别为500、600、700、800、900℃的铌酸锶钡(SBN)薄膜;对制备出SBN薄膜分别进行了椭偏光谱测量研究,得到了不同退火SBN薄膜椭偏光谱参数曲线;并对测得的椭偏光谱进行了数值反演计算,得到了不同退火温度的SBN薄膜的光学常数谱.结果发现SBN薄膜的折射率和消光系数都随着退火温度的增高而增大.     

Phase Formation During Nonisothermal Decomposition of the Freeze-Dried Bi:Pb:Sr:Ba:Ca:Cu = 1.8:0.4:1.8:0.2:1.2:2.0 Complex Nitrate Powder

Nitrate powder with cation composition Bi:Pb:Sr:Ba:Ca:Cu = 1.8:0.4:1.8:0.2:1.2:2.0 was obtained by spray-frozen, freeze-drying technique. Samples of the nitrate precursor powder were placed in a heated furnace (heating rate 100°C/min) and extracted in air when temperature of the powdered samples attained values of 439, 495, 550, 600, 640, 647, 717, 766, 814, and 850°C. Samples have been investigated by X-ray diffraction analysis. The obtained data allow us to propose and discuss phase formation and decomposition processes and reactions that occur in non-isothermal conditions at different temperatures during thermal decomposition of the nitrate powder.     

Flash-lamp-pumped Ho:Tm:Cr:YAG and Ho:Tm:Er:YLF lasers: modeling of a single, long pulse length comparison

Two methods of producing the long pulse lengths that promote efficient extraction of energy from low-gain, quasi-four-level lasers are analyzed. A long pulse length output can mitigate laser-induced damage effects and can be generated in quasi-four-level lasers by two disparate methods. One method utilizes Q-switching techniques in resonators designed to extend the pulse length and another utilizes the first pulse in a relaxation oscillation pulse train. Models for quasi-four-level lasers are derived here taking into account the nonnegligible thermal population of the lower laser level. Closed-form expressions are derived for both modes of operation of quasi-four-level laser systems so the parametric dependencies of both forms of operation become obvious, allowing facile comparison. In addition, a combined absorption and quantum efficiency, germane for flash-lamp pumping, is calculated for both Cr and Er sensitizers. Although the former has the advantage of broad absorption bands, the latter has the advantage of a quantum efficiency approaching 3.     

Flash-lamp-pumped Ho:Tm:Cr:YAG and Ho:Tm:Er:YLF lasers: experimental results of a single, long pulse length comparison

Flash-lamp-pumped, room-temperature Ho:Tm:Cr:YAG and Ho:Tm:Er:YLF are compared for single but long pulse operation, with pulse lengths of approximately 1.0 mus. Under similar operating conditions in normal-mode operation, a slope efficiency of 0.0331 was observed for Ho:Tm:Er:YLF compared with 0.0047 for Ho:Tm:Cr:YAG. For Q-switched operation, Ho:Tm:Er:YLF yielded a slope efficiency of 0.0075. In comparison, a slope efficiency of 0.0012 was obtained for Ho:Tm:Cr:YAG. Two methods of producing long pulse lengths are compared: pulse selection of normal-mode relaxation oscillations and Q-switching in a long resonator. Theoretical models developed in a companion paper for normal-mode relaxation oscillations and Q-switching in quasi-four-level solid-state lasers are in agreement with the experimental results.     

Electroluminescence of (Zn:Cd)S:Mn:Sm:Cl phosphors

The effect of field strength and frequency on electroluminescence brightness has been investigated for the binary systems (Zn:Cd)S:Mn:Cl and (Zn:Cd)S:Mn:Sm:Cl. The voltage dependence of the time averaged electroluminescent brightness shows the relation B = B_o exp ($\text{?}\text{C}\text{√}\text{v}$ and holds good over a wide range of frequencies, thus indicating that the mechanism of excitation is acceleration collision. The dependence of constants B_o and C on frequency of the applied field shows that the brightness of the electroluminescence is found to saturate at higher frequencies. It has been observed that EL peak emissions for these phosphors were found to be at 560 nm and 580 nm.     

Growth of YLF:Yb:Tm:Nd for optical applications

The focus of this study is the behavior of Tm, Yb and Nd ions in the LiYF₄ (YLF) crystal. One YLF crystal was successfully grown by the Czochralski method; it was doped with 20 mol% Yb, 1.3 mol% Nd and 0.05 mol% Tm. The segregation coefficients of the dopants and lattice parameters were determined. The spectroscopic properties of samples with different amounts of Nd were obtained from absorption and emission studies.     

Optical and EPR spectroscopy of Zn:Cr:ZnSe and Zn:Fe:ZnSe crystals

Optical and EPR characterization of Cr and Fe doped ZnSe crystals annealed in Zn vapor revealed a strong bleaching of the divalent state of transition metal ions. Photo induced EPR kinetics were studied in 20–80 K temperature range. Analysis of time-dependent data reveals Cr¹⁺ signal rise time decreases with increasing temperature. The non-exponential decay of Cr¹⁺ concentration were analyzed using Auger-type recombination process. The photoluminescence quantum yield of Cr²⁺ ions at ⁵E(D) → ⁵T₂(D) mid-IR transition excited via chromium ionization process was measured to be close to 100%.