Er3+/Yb3+共掺TeO2-WO3-Bi2O3玻璃的光谱性质和上转换发光

本文制备了Er³⁺/Yb³⁺共掺TeO₂-WO₃-Bi₂O₃(TWB)玻璃. 测试和分析了样品的吸收光谱、荧光光谱及上转换发光. 用Judd-Oflet(J-O)理论计算了Er³⁺在玻璃样品中的光谱强度参数,随着Bi₂O₃含量的增加,Ω₂增加,Ω₄ 关键词： 碲酸盐玻璃 光谱性质 上转换     

B2O3-Na2O-CaO-SiO2玻璃结构的拉曼光谱研究

制备了B₂O₃-Na₂O-CaO-SiO₂四元系若干玻璃样品,通过实验拉曼光谱和量子化学从头计算相结合的方法,对其微观结构进行了定性定量研究。结果表明,随着B₂O₃的加入,硅酸盐转变为硼硅酸盐结构。当质量比CaO/SiO₂=1时,B主要以[BO₃]的形式参与网络形成,并在B₂O₃含量为6 Wt%时迹象明显。拉曼光谱精细结构解谱的结果表明,B的加入使结构复杂化,体系中Q₁相对含量减少,Q₃相对含量增加,整体由以Q₂为主变为以Q₂、Q₃为主。     

Ge28Sb6S(66－x)Sex玻璃系统光学特性与结构

采用熔融-急冷法制备了系列Ge₂₈Sb₆S_(66－x)Se_xSe_x(x=0,10,20,30摩尔比)硫系玻璃样品.分别测试了样品的密度、折射率、可见-近红外透过光谱、红外透过光谱以及喇曼光谱,并分析了在Ge-Sb-S中引入Se对其物理、光学特性的影响.利用喇曼光谱讨论了玻璃的结构与特性之间的关系.结果表明：随着Se含量的增加,样品的密度和线性折射率都增大,可见和红外截止波长都发生红移,纯硫化物玻璃样品主要由GeS₄四面体和SbS₃三角锥组成,随着Se逐渐代替S,硫-硒混合样品中逐渐出现了GeS_4－xSe_x结构单元以及链状和环状的Se-Se键.     

B2O3含量对掺铒碲铌酸盐玻璃光谱性质及热稳定性影响

制备了一系列碲铌酸盐玻璃85TeO₂-(15-x)Nb₂O₅-xB₂O₃-1%Er₂O₃(TNBx=0, 3, 6, 9, 12, 15).根据Judd-Ofelt(J-O)和McCumber理论,讨论和分析了B₂O₃含量对掺铒碲铌酸盐玻璃热稳定性及光谱性质影响.研究发现,玻璃开始析晶温度和玻璃转变温度差值ΔT(T_x-T_g),J-O强度参数,FWHM和峰值受激发射截面的乘积在B₂O₃引入摩尔分数为9%时达到最大值.同时,Er³⁺:⁴I_13/2能级寿命也随着B₂O₃含量的增加而单调增加.结果表明,在掺铒碲铌玻璃中,适量的B₂O₃能较好地提高玻璃的热稳定性能和Er³⁺离子的光谱性质.     

Nonlinear optical properties of 75TeO2－20Nb2O5－5ZnO glasses doped with CeO2

Nonlinear optical properties of 75TeO_2－20Nb_2O_5－5ZnO glasses doped with CeO_2 have been investigated with a self-diffracted time-resolved degenerate four-wave mixing (DFWM) technique at different excitation intensities and lattice temperatures. The DFWM signal exhibits three peaks at higher excitation intensities, where a main peak appears at zero delay time and two rather weak side peaks are located symmetrically at the negative and positive time delay. Due to destructive interferences between the fifth- and third-order polarizations, the line-shape of the main peak around the zero time delay evolves from single peak into a double-peak structure with increasing excitation intensity. Two side peaks emerge at the positive and negative time delay and gradually intensify with increasing excitation intensity or lattice temperature, and their positions are independent of the pulse duration, temperature and excitation intensity, which are attributed to the many-body Coulomb interaction.     

掺杂CeO2的75TeO2-25Nb2O5-5ZnO飞秒激光诱导瞬态光栅的研究

用泵浦探测技术研究了掺杂CeO₂的75TeO₂-25Nb₂O₅-5ZnO玻璃在飞秒激光诱导的瞬态光栅多级自衍射。从拉曼和吸收光谱中研究了玻璃的结构特性，并证明了此玻璃中存在Ce3+离子。这种瞬态光栅起因于光克尔效应，并通过Ce3+离子中1S0?1F3电子能级跃迁形成的激发态粒子数光栅而改善，一级衍射信号的转换效率可达到11%。这些实验结果显示了掺杂CeO₂的75TeO₂-25Nb₂O₅-5ZnO飞玻璃在全转换开关中具有广泛应用。     

镧碲酸盐玻璃的振动模式和结构的拉曼散射

利用拉曼光谱研究xLa₂O₃-(1-x)的TeO₂(x=0、0.05、0.10、0.15、0.20和0.25)镧碲酸盐玻璃,并对镧碲酸盐玻璃形成过程中氧化镧变化引起的结构变化进行了分析. 强度测量表明,在高频的伸缩振动区域,组合物被诱导发生结构变化. 通过混合TeO₄三角双锥和TeO₃三角金字塔单元形成网络结构的镧碲酸盐玻璃. 改变氧化镧的含量导致TeO₄单元向含有不同数目的非桥氧原子的TeO₃单元转换.通过不同的氧桥三角双锥和三角金字塔碲酸盐结构单元的振动拉曼谱带轮廓分析计算出发生结构变化的组合物的相对量. 另外,通过拉曼强度和与碲酸盐网络结构有关的结构估算出末端氧原子的比例. 对改性剂含量高达25％的镧碲酸盐玻璃的模拟结果表明,短程有序的单元足以构建整个玻璃.     

碲酸盐玻璃的拉曼光谱研究

本文测试了TeO2-ZnO和TeO2-BaO两种二元系统不同金属氧化物浓度下玻璃的拉曼光谱,通过比较这两种碲酸盐玻璃系统拉曼光谱的异同,表明碲酸盐玻璃系统中随着金属氧化物浓度的增加,使玻璃网络中的TeO4双三角锥向TeO3三角棱锥转化,并且在TeO2-BaO二元玻璃中出现了非桥氧键。同时初步研究了TeO2-ZnO-Na2O三元玻璃的拉曼光谱,发现当TeO2-ZnO二元玻璃中加入5mol%的Na2O时,其结构并没有发生显著的变化。     

Preparation and spectral characterization of new Er3+-doped TeO2－B2O3－WO3－ZnO－ZnS glasses

Erbium-doped TeO_2-based oxysulfide glasses have been prepared in argon atmosphere in graphite crucibles. The results of thermal analysis and spectroscopic properties of Er^{3+} have been studied in terms of sulfide influence. As a function of composition, we have measured principally the optical absorption, spontaneous emission, and lifetime of the materials. Judd－Ofelt theory was introduced to calculate bandwidth and emission cross-section of Er^{3+}. The results demonstrate that addition of sulfide in tellurite glasses results in broad emission spectra, with high emission cross-section, slightly low emission lifetime and a comparatively high thermal stability as pure oxide glasses.     

Na2O-K2O-Al2O3三元系固体结构研究

制备了xNa₂O-(1-x)K₂O-Al₂O₃(x=0.33, 0.50, 0.66, 1)三元系固体,实验利用拉曼光谱技术获得了xNa₂O-(1-x)K₂O-Al₂O₃三元系固体的常温拉曼光谱和升温拉曼光谱,使用CASTEP软件优化晶体结构和计算拉曼光谱,获得了xNa₂O-(1-x)K₂O-Al₂O₃三元系样品的常温拉曼光谱,结果表明低波数区(100～400 cm^-1)的拉曼特征峰为Na—O键的振动。中波数区(400～700 cm^-1)的拉曼特征峰为铝氧四面体中桥氧键的振动。高波数区(700～1 000 cm^-1)的拉曼特征峰为Al-O_nb的振动。对三元系样品的拉曼特征峰进行有效归属。获得了0.5Na₂O-0.5K<...     

TeO2-Nb2O5-YF3 玻璃系统的形成区及性质研究

制备了一种新型的氧卤碲酸盐玻璃:TeO2-Nb2O5-YF3,给出并研究了TeO2-Nb2O5-YF3三元系统的玻璃形成范围。测试了玻璃的密度、折射率、差热(DTA)、拉曼光谱、红外透射光谱以及紫外吸收光谱,通过光谱分析研究了组分含量的变化对玻璃结构及红外透射特性的影响。实验结果表明,TeO2-Nb2O5-YF3玻璃系统具有优良的成玻璃性能和热稳定性等特性,而且在2.8~3.3μm区域内无明显的[OH]基团吸收,在中红外3~5μm区域具有优良透射性能,因此在中红外透射方面具有潜在应用价值。     

TeO2-TiO2-Bi2O3系统玻璃的热学特性及光学带隙研究

采用熔融淬冷法制备了系列高折射率的TeO2-TiO2-Bi2O3系统玻璃,测试了样品的密度、转变温度、析晶温度、折射率、吸收光谱,利用经典的Tauc方程计算了样品光学带隙允许的直接跃迁、允许的间接跃迁及Urbach能量.讨论了玻璃的热稳定性与组成之间的关系、研究了摩尔折射度、金属标准值、光学带隙、Urbach能量、Bi2O3和TiO2含量及光学碱度对玻璃样品折射率的影响.结果表明TeO2-TiO2-Bi2O3玻璃具有较好的热稳定性、样品的折射率随着摩尔折射度增大而增大,而光学带隙及金属标准值有减小的趋势,此外高的光学碱度对玻璃的高的三阶非线性也有一定的贡献.     

具有高机械强度的掺Er3+∶TeO2-Nb2O5玻璃的光谱性质研究

熔制了掺铒碲铌玻璃样品(100-XTeO2-XNb2O5(X=5,10,15,20 mol%),测试了其密度、折射率、转变温度、析晶温度、维氏机械强度、吸收光谱、荧光光谱、荧光寿命等参量。利用Judd-Ofelt和McCumber理论分别计算了铒离子强度参量Ωt (t=2, 4, 6)和受激发射截面σemi的大小,研究了掺铒碲铌玻璃样品光谱参量对Nb2O5成分的依赖性,并与典型的碲锌钠玻璃（75TeO2-20ZnO-5Na2O）在热学、机械强度、光谱性质和放大品行四个方面进行了比较.     

Raman and infrared structural investigation of (PbO)x(ZnO)(0.6−x)(P2O5)0.4 glasses

The structure of ternary (PbO)_x(ZnO)_(0.6−x)(P₂O₅)_0.4glasses was investigated using Raman scattering and infrared spectroscopy over the compositional range x = 0–0.6. No significant change of the average chain length composed by PO₄ tetrahedral units with the substitution of zinc for the lead cation was observed. The linewidth and wavenumber variations of the Raman high‐wavenumber bands reflect the Zn/Pb substitution in these glasses and are correlated with the metal–oxygen force constant and local disorder. The infrared reflectivity spectra have been fitted with the four‐parameter dielectric function model. The variation in the 1000–1200 cm⁻¹wavenumber range has been attributed to an increase of the oscillator damping Γ_LO(PO₃)₂₋ as with PbO content vibrations rather than a variation of the chain length. Copyright © 2008 John Wiley & Sons, Ltd.     

Broadband 1.5-μm emission of erbium-doped TeO2-WO3-Nb2O5 glass for potential WDM amplifier

Erbium-doped glass showing the wider 1.5-/μm emission band is reported in a novel oxide system TeO2-WO3-Nb2O5 and their thermal stability and optical properties such as absorption,emission spectra,cross-sections and fluorescence lifetime were investigated.Compared with other glass hosts,the gain bandwidthproperties of Er3+ in TWN glass is close to that of bismuth glasses,and larger than those of tellurite,germanatc,silicate and phosphate glasses.The broad and flat 4I13/2 → 4I15/2 emission and the largestimulated emission cross-section of Er3+ ions around 1.5 μm can be used as host material for potentialbroadband optical amplifier in the wavelength-division-multiplexing(WDM)network system.     

镨掺杂碲铌铅玻璃的光学性能

研究了掺稀土离子Pr^3 的碲铌铅玻璃的吸收光谱,色度色散和非线性光学性能。结果表明：高浓度的Pr^3 引入到碲铌铅玻璃系统后,仍能够形成均匀透明的玻璃,该玻璃具有高的折射率和非线性折射率。     

Inelastic light scattering in strontium borate glasses in the systemxSrO.(1−x)B2O3 and (SrCl2) y .[xSrO.(1−y−x)B2O3]1−y

Raman spectra of strontium borate binary glasses in the systemxSrO.(1-x)B₂O₃ forx=0.20, 0.25, 0.30, 0.35, 0.40, and 0.50 and ternary glasses in the system (SrCl₂) _y .[xSrO.(1−y−x)B₂O₃]_1−y fory=0.10, 0.20, 0.30 and 0.40 andx=0.20 and 0.35, are reported. Raman spectra of the glasses show experimental evidence of glass network modifying nature of SrO in borate matrix. SrO causes a change of boron atom coordination number from 3 to 4 resulting in the complex structural groupings comprising of BO₄ and BO₃ units. Strontium cations are not easily accommodated in the glass structure and tend to break up the network at high concentration (x) of SrO, causing non-bridging oxygens. The effect of temperature variation of binary glasses has also been studied. The introduction of SrCl₂ to the binary stronium borate glass causes a large change in intensity of low frequency Raman scattering whereas there is no change in the vibrational dynamics in the high frequency region. The temperature reduced Raman spectra represents true vibrational density of states. Martin-Brenig model developed for the low frequency region has been discussed to obtain the structural correlation range in the glass.     

Nd3+掺杂B2O3-Nb2O5-BaO-La2O3玻璃光谱性质的研究

 用高温熔融法制备了Nd³⁺(物质的量分数2％）掺杂40B₂O₃-(15-χ)Nb₂O₅-45BaO-χLa₂O₃玻璃，测量了样品的吸收光谱、发射光谱和差热分析（DTA）曲线。根据Nd3+光学跃起矩阵的特点，应用Judd-Ofelt理论，从吸收光谱获得了Nd³⁺光学跃起的强度参数。并计算了Nd³⁺离子的自发辐射跃迁几率、总自发辐射几率、荧光分支比、辐射能级寿命和受激发射截面。结果表明：该体系玻璃中，随着Nb₂O₅ 含量的增加和La₂O₃₂增大，说明材料的对称性降低；而Ω₆减小，说明Nd-O键的共价性和键强增强；受激发射截面减小。DTA实验表明，随着Nb₂O₅含量的增加，材料的热稳定性提高。     

掺Er3+玻璃的光限幅特性研究

利用波长为532 nm的皮秒脉冲激光,研究了掺Er3 玻璃的光限幅特性和反饱和吸收.当入射功率不断增加且超过一定阈值时,透射功率不再随着入射功率快速增大,而是逐渐趋向于较稳定状态,从而实现了对强激光的光限幅效应.进一步利用布居速率方程讨论了其机制并给出了激发态的吸收截面,结果表明激发态吸收是其主要的光限幅机理.