一种可用于可调谐环行Ti：Al_2O_3激光器的宽带单向器

本文介绍一种宽带单向器的原理及设计。选用ＴＧＧ作磁旋光介质，旋光石英晶片作补偿片，所设计的色散补偿型宽带单向器预计可在７００～１０００ｎｍ波长范围内实现环行激光腔中的单向行波运行；将其应用在可调谐环行Ｔｉ：Ａｌ２Ｏ３激光器中，获得了良好的实验结果。     

可调谐钛宝石双波长激光在β－BaB2O4晶体中和频

本文用矩阵光学推导出了相位共轭腔的热稳条件。     

自启动、低功率泵浦的自锁模Ti：蓝宝石激光器和它的高效连续运转

报道了一台自启动、长时间稳定、低功率泵浦的自锁模Ｔｉ：蓝宝石激光器和它的高效连续运转的实验结果．实验中观测到５３ｎｍ的光谱带宽（ＦＷＨＭ）．此谱宽可支持１３ｆｓ的激光脉冲．受自相光仪测量仪器的限制．测得的脉宽为２４．６ｆｓ．实际脉冲脉宽可能小于２０ｆｓ．此激光器在自启动锁模、低功率泵浦时．脉宽小于５０ｆｓ．激光器在连续运行时获得０．２Ｗ的泵浦阈值．３５％的斜率效率和１．１Ｗ的激光输出（４Ｗ泵浦）．     

掺钛蓝宝石晶体激光放大实验研究

报道了掺钛蓝宝石晶体激光放大实验研究，实验中得到最大的单程放大和双程放大增益分别为１４．７６和２６．３１，对应双程放大的增益系数为１．８１ｃｍ－１，并由此推算出掺钛蓝宝石晶体的增益截面为２．７４×１０－１９ｃｍ２，饱和能量密度为０．９３Ｊ／ｃｍ２．并给出不同的泵浦能量密度所对应的最佳放大介质长度。实验表明小信号近似下，放大增益只与泵浦功率密度有关．与注入种子能量无关。实验还测量了掺钛蓝宝石晶体对不同波长种子光的放大增益。     

YAG激光器泵浦钛宝石激光器和光学参量振荡器

采用一台调Q脉冲式Nd：YAG激光器同时泵浦Ti：蓝宝石激光器和光学参量振荡器（OPO），在重复频率30Hz下获得了Ti：蓝宝石可调谐激光波长为700～890nm，转换效率28．8％及440～2600nm的连续可调谐窄线宽的光参量激光输出，能量转换效率达23％。     

（Ti,Al）N薄膜光学性能的研究

研究了（Ｔｉ，Ａｌ）薄膜的光学特性，对其反射和透射光谱作了仔细分析。运用Ｈａｄｌｅｙ方程，算出一定成分（Ｔｉ，Ａｌ）Ｎ膜的折射率ｎ，消光系数ｋ随波长的变化关系。又根据透射曲线，计算出了（Ｔｉ，Ａｌ）Ｎ膜的光隙能。     

Study of Optically Stimulated Luminescence of LiF:Mg,Ti for beta and gamma dosimetry

Modern advances in radiation medicine – radiodiagnosis, radiotherapy and interventional radiography – each present dosimetry challenges for the medical physicist that did not exist previously. In all of these areas a constant balance has to be made between the treatment necessary to destroy the tumor and the unnecessary exposure of healthy tissue. Innovative applications of OSL dosimetry are now appearing in each of these areas to help the medical physicist and oncologist design the most effective, and least deleterious, treatment for their patients. High sensitivity, precise delivery of light, fast readout times, simpler readers and easier automation are the main advantages of OSL in comparison with TLD.This work aimed to study the application of OSL technique using lithium fluoride dosimeters doped with magnesium and titanium (LiF:Mg,Ti) for application in beta and gamma dosimetry.     

Electrochemical and Structural Characterisation of Dip-Coated Fe/Ti Oxide Films Prepared by the Sol-Gel Route

Thin solid films of mixed Fe/Ti oxide composition (Fe/Ti molar ratios: 0.5∶1, 1∶1, 1.5∶1) have been made from Fe(NO₃)₃ alcoholic solution to which Ti(OiPr)₄ was added. Films have been deposited by the dip-coating technique and heat-treated at 300°C and 500°C. Powders of Fe/Ti oxide heat-treated at 300°C are amorphous, while powders annealed at 500°C for 40 hours transformed to mixed rutile, pseudobrookite and hematite phases. The structure of the XRD amorphous films was identified with the help of near-normal reflection absorption (6°) (IRRA) and near-grazing incidence angle (NGIA) spectroscopy. NGIA FT-IR spectra of films are characterised with a single phonon mode appearing in the spectral range 600–950 cm⁻¹ which shifts with increasing Ti concentration from 675 cm⁻¹ (Fe₂O₃) to 904 cm⁻¹ (TiO₂) thus exhibiting one-mode behavior. Electrochemical investigations made with the help of cyclic voltammetry (CV) and chronocoulometry (CPC) performed in 0.01M LiOH and in 1M LiClO₄/propylene carbonate electrolytes revealed that films are able to uptake reversibly Li⁺ ions with a charge capacity (Q) per film thickness (d) in the range 0.1–0.26 mC/cm²nm and 0.06 mC/cm²nm, respectively. The temperature at which the films were prepared alters the rate of Li⁺ insertion which is faster for less compact films obtained at 300°C. In situ UV-VIS spectroelectrochemical measurements revealed that Fe/Ti oxide films bleached in the UV spectral region (300 nm<λ<450 nm) and colored in the VIS spectral region (450 nm<λ<800 nm), thus exhibiting mixed anodic and cathodic electrochromism.     

Theoretical studies on the infrared spectrum of the tetrahedral molecules R<Subscript>2</Subscript>MH<Subscript>2</Subscript> (R = D(H), CH<Subscript>3</Subscript>, OH; M = Ti,Zr, Hf)

Using Stuttgart/Dresden effective core potentials MWB28, MWB60, and GTO valence basis sets (8s7p6d)/[6s5p3d], (8s7p6d)/[6s5p3d] for Zr and Hf atoms and 6-311++G(3df,3pd) basis set for C, H, O, and Ti atoms, tight convergence criteria geometry optimizations and harmonic frequency calculations are performed at B3LYP and B3LYP/IEF-PCM levels of theory so as to model the gas phase and argon matrix infrared spectra of the tetrahedral molecules R₂MH₂ (R = D(H), CH₃, OH; M = Ti, Zr, Hf). Influence of the transition metal and/or substituent group on the symmetric and asymmetric stretching frequencies of the MH₂ fragment of the R₂MH₂ molecules is investigated at both the levels of theory. The modelling of the argon matrix effect improves the agreement between the calculated frequencies and the experimental ones. The calculated argon matrix to gas phase frequency shifts is compared reasonably to the experimental argon to neon matrix shifts.     

烧结温度和升温速率对Pb(Sb1/3Mn2/3)0.05Zr0.47Ti0.48O3压电陶瓷性能的影响

采用传统固相法制备了Pb(Sb1/3 Mn2/3)0.05Zr0.47Ti0.48 O3 (PMS-PZT)压电陶瓷.利用XRD、SEM和EDS等研究PMS-PZT陶瓷体系在烧结过程中形成的过渡液相和形成过渡液相温度(1100℃)附近的升温速率对陶瓷结构、压电和介电性能的影响.结果表明:不同烧结温度下,所有样品均为单一的钙钛矿四方相,过渡液相不会对相的结构有影响,但是当烧结温度较低时,过渡液相在烧结后期以玻璃相在晶界附近富集,对陶瓷的压电和介电性能有很大影响.随着烧结温度和升温速率的升高,PMS-PZT晶粒尺寸增大,晶粒均匀性和规则性得以改善,晶化质量得到提高;d33测试和阻抗分析测试结果表明PMS-PZT样品在1100℃附近以7 ℃·min-1升温速率并在1250℃烧结时具有最好的压电和介电性能:d33 =313 C/N,kp=0.59,Qm=1481,εr=1437,tanδ=0.53;.