掺铒钙铝硅玻璃的光学带隙

玻璃中稀土掺杂的离子的光谱性质受其周围的玻璃结构和在玻璃基质中的分布影响很大。利用熔融法制备了组分为9S iO2.26A l2O3.65CaO.1.0Er2O3.0.3Yb2O3和分别加入MgO以及La2O3的掺铒钙铝硅玻璃,并研究了其吸收边和光学带隙。计算得出离子填充比随玻璃的平均摩尔质量的增大而减小,同时利用Judd-O felt模型计算出该玻璃体系的Ω2,Ω4和Ω6参数,并进行了分析。随着MgO或La2O3的加入,吸收边向短波长移动,光学带隙增大,同时Ω2和Ω6值也增大。对ln(α)和ω的曲线进行线性拟合可以计算Urbach能量,其值与光学带隙的变化趋势一致。     

Spectroscopic properties of Er3+-doped AlF3-La2O3-Al2O3-SiO2 glasses

Er3+-doped fluoride lanthanum aluminosilicate glasses with compositions of (65- x/2)SiO2 · (25 -and their glass transition temperatures and spectroscopic properties were investigated. The Ω2, Ω4, and Ω6 intensity parameters of glasses were calculated by Judd-Ofelt theory from absorption curves. It was found that glasses transition temperature and melting temperature decreased with the increase of fluoride content in glass, Ω2 decreased gradually with the increase of AlF3 content, but both Ω4 and Ω6 did not increase until AlF3 content increased to 30 mol%. The quantum efficiency of 4I13/2 to 4I15/2 transition of Er3+ ions increases with the increase of AlF3 content in glass. Fluorescent lifetime is longer in glass containing more AlFa content.     

Novel Tm~(3+)-doped transparent fluorozirconate glass-ceramic containing nanocrystalline

A new transparent Tm3+-doped ZrF4-based nanocrystallized glass with the composition of 55ZrF4-20BaF2-18.8YF3-5AlF5-1.2TmF3 (mol%) (ZBYA) has been prepared by a conventional melting quenching technique and the subsequent heat treatment processes. The glass characteristic temperatures, the apparent activation energy, and the Avrami parameter for crystallization are estimated on the basis of different scanning calorimetry (DSC). The sizes of grown nanocrystals in the glass matrix appear to be 30-36.5 nm and it is studied as a function of the nucleation temperature, also the peak intensity of the nanocrystalline is studied as a function of the nucleation temperature from the X-ray diffraction (XRD) measurement. The rnicrohardness measurement shows that the Vickers microhardness (Hv) values of the heat-treated glass samples are larger than that of the based glass about 17.26%-42.04%.     

Effects of Yb^3＋ in Er^3＋/Yb^3＋ Codoped Fluorophosphate Glasses

For the Er^3＋ /Yb^3＋ codoped fluorophosphate glasses, Judd-Ofelt theory is used to analyse the influence of YbF3 as not a sensitizer but an average component on the spectroscopic properties around 1530nm emission. The double roles of Yb^3＋, as a sensitizer and as an average component, are discussed. It is found that Yb^3＋ as an average component contributes to the increase of fluorescence lifetime, and Yb^3＋ as a sensitizer has the best sensitization when its concentration is 2.4 mol%.     

Ce3+掺杂SiO2-Al2O3-Gd2O3玻璃的闪烁性能

通常, Ce离子掺杂的低密度玻璃有较高的发光效率, 而高密度的Ce离子掺杂玻璃其发光效率很低. 为了解释这一现象, 采用高温熔融法获得了SiO₂-Al₂O₃-Gd₂O₃三元系统的玻璃形成区, 并在还原气氛下制备了Ce³⁺掺杂SiO₂-Al₂O₃-Gd₂O₃以及SiO₂-Al₂O₃-Gd₂O₃-Ln₂O₃ (Ln=Y, La, Lu)闪烁玻璃, 研究了其光谱和闪烁性能. 测试结果显示: 随着Gd₂O₃含量增加, 玻璃紫外截止波长发生红移, 荧光强度降低, 衰减时间缩短; 加入Lu₂O₃, La₂O₃, Y₂O₃后, 紫外截止波长发生红移, 荧光强度降低, 衰减时间变短; 当Gd₂O₃超过10% mol时, X射线荧光积分光产额从相当于锗酸铋 晶体的61%降低到13%. 荧光强度降低、衰减时间缩短的原因是随着玻璃的紫外截止波长红移玻璃的能带宽度变窄, 使得Ce³⁺离子的d电子轨道开始接近玻璃的导带, Ce³⁺离子受辐射后跃迁到d电子轨道的电子会通过导带与玻璃中的空穴复合, 产生电荷迁移猝灭效应.     

Determination of energy constants for Yb3＋/Er3＋ transfer and upconversion codoped phosphate glass

The energy transfer and cooperation upconversion processes are investigated in Yb3＋/Er3＋ codoped phos- phate glass. Based on the measured curves of output power versus incident power, the laser and spectroscopic parameters of the glass are fitted and analyzed. We focus on the resonant energy transfer constant k from Yb3＋ to Er3＋ as well as the cooperation upconversion coefficient Cup from 4113/2 of Era＋. The fitted k and Cup can give almost the same results for different thicknesses of glass disk with the same dop- ing concentrations. The determination of these parameters is helpful for the development of Yb3＋/Er3＋ codoped laser glass.     

Enhancement of up-conversion Yb3＋/Tm3＋/Er3＋ tri-doped tellurite glass luminescence properties in transparent oxyfluoride ceramics

Optically transparent Er3＋/Tm3＋/Yb3＋ tri-doped oxyfluoride tellurite based nano-crystallized glass ceramics with the batching composition of 73TeO2-15ZnO-7ZnF2-3YF3-1.5YbF3-0.3ErF3-0.2TmF3 （mol%） is prepared by a conventional melting quenching and the subsequent heat treatment processes. The sizes of grown nano-crystals in glass matrix appear to be smaller than 100 nm from the scanning electron mi- croscope measurement. Visible up-conversion luminescence of the as melted glass and glass ceramics is investigated. The three-color up-conversion luminescence intensities by 980-nm pumping are increased significantly due to the heat treatment, and the blue intensity increases with a higher magnitude than other wavelengths after heat treatment.     

具有AIE效应的Eu(Ⅲ)-聚(N-乙烯基吡咯烷酮)配位聚合物Pdots的制备及双色肿瘤细胞成像

本研究通过原位引发聚合方法,以合成的4,4'-偶氮（4-氰基戊酸酯基）四苯乙烯（TPE-tetraAZO）为引发剂,引发乙烯基吡咯烷酮单体聚合,并通过侧链含孤对电子的N、O元素与稀土Eu（III）配位,成功制备四臂星型聚合物TPE-tetraPVP-Eu（III）,该双亲性聚合物可自组装成尺寸约为20 nm的非半导体型聚合物量子点（Pdots）.光学性能研究表明：该Pdots在360 nm和395 nm激发下分别发射蓝色（435 nm）和红色（615 nm）荧光,其中,Pdots的蓝色荧光具有典型的AIE特性,并对环境温度和pH具有明显双重响应特性,最低临界温度为37℃,接近人体温度.此外,Pdots表现出低细胞毒性,可通过调节激发波长,实现对HeLa、HepG2及A549三种肿瘤细胞的可逆双色荧光成像,展现出优异的成像效果,有望作为一种活细胞多色荧光示踪探针材料.     

Ag+-Li+离子交换制作Er3+/Yb3+共掺磷酸盐玻璃平面光波导

制备了化学稳定的Er3+/Yb3+共掺的磷酸盐玻璃,并在其中制作了用于光放大器和激光器的平面光波导.这种磷酸盐玻璃的失重速率为4.7×10－5g·cm－2·hr－1,小于Kigre公司商业化的磷酸盐玻璃QX/Er的失重速率.采用Ag+-Li+交换技术制作了平面光波导并用m-线光谱在632.8 nm测量了平面光波导的有效折射率.根据反WKB法得到折射率形貌,计算了离子交换参数如:离子交换深度、表面折射率,折射率改变和扩散系数等.     

2 μm mode-locking laser performances of sol-gel-fabricated large-core Tm-doped silica fiber

High-power ultrafast fiber lasers operating at the 2 μm wavelength are extremely desirable for material processing, laser surgery, and nonlinear optics. Here we fabricated large-core(LC) double-cladding Tm-doped silica fiber via the sol-gel method. The sol-gel-fabricated Tm-doped silica(SGTS) fiber had a large core diameter of 30 μm with a high refractive index homogeneity(Δn=2 × 10~(-4)). With the newly developed LC SGTS fiber as the gain fiber, high-power mode-locking was realized. By using a semiconductor saturable absorber mirror(SESAM) as a mode locker, the LC SGTS fiber oscillator generated mode-locked pulses with an average output power as high as 1.0 W and a pulse duration of 23.9 ps at the wavelength of 1955.0 nm. Our research results show that the self-developed LC Tm-doped silica fiber via the sol-gel method is a promising gain fiber for generating high-power ultrafast lasers in the 2 μm spectral region.