Er/Yb共掺体系的光致荧光行为及相关物理过程研究

采用固相反应方法，制备了Er₂O₃浓度固定为0.5mol%，Yb₂O₃浓度范围为0.0mol%—5.5mol%的Er/Yb共掺激光玻璃.通过吸收光谱、光致荧光光谱和上转换荧光光谱，研究了Yb₂O₃浓度对Er³⁺荧光特性的影响，并探讨了相关的物理机制.研究结果表明：Yb³⁺共掺对Er³⁺的⁴ 关键词： Er/Yb共掺 光致荧光 能量传递 合作上转换     

Er/Yb共掺硅酸盐玻璃的光致发光

采用固相反应方法，制备了Er³⁺离子浓度为0.5 at.%，Yb掺杂浓度范围为0.0— 6.0 at.%的Er/Yb共掺激光玻璃，并对激光玻璃的吸收光谱和光致荧光光谱进行了分析.研究 结果显示，Yb³⁺掺杂对Er³⁺在980 nm附近的吸收起到了非常显著的 增强作用.在 980 nm的激光抽运下，激光玻璃在1530 nm处的光致发光强度随着Yb离子浓度 的增加而先增大后减小， 当Yb³⁺离子浓度为Er³⁺离子浓度6倍时光 致发光强度达到最大值.同时还发现了Yb³⁺对Er³⁺的光致荧光光谱 的展宽作用，并讨论了荧光光谱的展宽机理. 关键词： Er/Yb共掺玻璃 光致发光 吸收光谱     

Er3+/Yb3+共掺的氧化镧钇透明陶瓷的光谱性能研究

采用传统无压烧结工艺制备了Yb³⁺/Er³⁺共掺的氧化镧钇透明陶瓷并对其光谱性能进行了研究.样品具有较大的吸收和发射截面.La₂O₃的添加使样品的荧光寿命(τ_s)与玻璃接近，当Yb³⁺和Er³⁺的掺杂量分别为5at%和0.5at%时，测得τ_s=9.65　ms.这种荧光寿命长、发射截面大和线宽窄的特性有利于微型、可集成化和大功率激光输出的实现. 关键词： 透明陶瓷 吸收光谱 发射光谱 荧光寿命     

TeO2-ZnO-Na2O-K2O玻璃中Er3+离子掺杂浓度对其发光及荧光寿命的影响

测量了不同掺杂浓度下Er³⁺离子在碲酸盐玻璃中的吸收光谱、发射光谱和Er3+离子的荧光寿命，计算了Er³⁺离子的发射截面σ_e,分析 了Er ³⁺离子掺杂浓度对其发光强度和荧光寿命的影响.结果表明，Er³⁺离子掺 杂浓度较低时，对其荧光强度和荧光寿命没有显著的影响；掺杂浓度高时，出现了浓度猝灭 效应，使Er³⁺离 子荧光光强度降低，荧光寿命下降.实验确定了掺杂浓度最优值，同时对浓度猝灭机制进行 了分析. 关键词： 碲锌碱玻璃 3+离子')" href="#">Er³⁺离子 掺杂浓度 发光和荧光寿命     

掺铒矾酸钇晶体上转换荧光研究

使用波长为808和658nm的半导体激光器和染料激光器作为激发源，测量了Er³⁺：YVO₄晶体的波长在553和410nm附近的上转换荧光.对激发过程的分析表明，贡献于上转换荧光的主要激发机制为激发态吸收.在不同浓度下对上转换荧光的寿命测量结果显示，随Er³⁺浓度的提高，553nm绿光的荧光寿命随浓度的增加而减小，但410nm的荧光寿命随Er³⁺浓度无明显变化.结合绿光强度随掺杂浓度增加而减小的结果，认为在所测浓度范围内 关键词：     

退火温度对Er/Yb共掺Al2O3薄膜的光致荧光光谱的影响

通过对不同退火条件下Er/Yb共掺Al_２O_３薄膜光致荧光(PL)光谱的 系统分析，研究了高Er/Yb掺杂浓度所导致的晶体场变化对薄膜PL光谱的影响，并结合薄膜结构分析，探讨了Al_２O_３薄膜的结晶状态在Er^３＋激活、PL光谱宽化 中的作用及可能的物理机理.研 究结果表明：退火处理所导致的Er^３＋ PL光谱的变化与薄膜的微观状态之 间有着密 切的联系.在600—750℃范围内，薄膜呈非晶态结构，薄膜荧光强度的增加主要是薄膜内缺 陷减少所致；在800—900℃范围内，γ-Al_２O_３相的出现是导致荧 光强度明显增加的主 要原因；当退火温度为1000℃时，Er，Yb的大量析出致使荧光强度的急剧下降.此外，对PL 光谱线形分析表明，各子能级跃迁的相对强度变化是导致荧光光谱宽化的主要因素. 关键词： Er/Yb共掺 ２O_３薄膜')" href="#">Al_２O_３薄膜 光致荧光     

Er3+及Er3+/Yb3+共掺铋酸盐玻璃光谱性质研究

制备了Er³⁺及Er³⁺/Yb³⁺共掺铋酸盐玻璃，测试了样品的吸收光谱、荧光光谱.应用Judd-Oflet理论计算了Er³⁺在铋酸盐玻璃中的光谱强度参数，分别为Ω₂=(5.47—2.92)×10^-20cm²，Ω₄=(2.16—1.22)×10^-20cm², 关键词： 3+')" href="#">Er³⁺ 铋酸盐玻璃 3+/Yb³⁺共掺')" href="#">Er³⁺/Yb³⁺共掺 光谱性质     

荧光俘获效应对掺饵氧化物玻璃光谱性质的影响

测试了不同掺杂浓度和样品厚度下掺铒磷酸盐和碲酸盐玻璃的吸收光谱、荧光光谱和荧光寿 命，计算了Er³⁺离子在1.53 μm处的吸收截面(σ_a)、发射截面(σ _e)、自发辐射跃迁概率(A_rad)、辐射跃迁寿命(τ_rad) 、以及辐射跃迁量子效率(η)等光谱参数.讨论了荧光俘获效应对掺铒磷酸盐和碲酸盐玻璃 光谱性质及光谱参数的影响.结果表明即使在铒离子低掺杂浓度(0.1 mol% Er₂O ₃)下，荧光俘获效应也普遍存在于掺铒玻璃材料中，使得荧光寿命(τ_{f)和荧光半高宽(FWHM)随样品的厚度和铒离子掺杂浓度增加而增大，导致碲酸盐和磷酸 盐玻璃中τf分别增加11%—37％和6%—17%，FWHM分别增加15%—64%和11%—55% ，使得掺铒玻璃材料的放大品性参数(σe×FWHM) 也相应被估高.由于铒离子在 碲酸盐玻璃中在1.53 μm处吸收和发射截面重叠面积较大，加之铒离子在前者基质中的发射 截面高于后者，使得掺铒碲酸盐玻璃中的荧光俘获效应高于磷酸盐玻璃. 关键词： 荧光俘获 铒离子 碲酸盐玻璃 磷酸盐玻璃}     

低温下Er3+/Yb3+共掺碲酸盐玻璃的发光特性研究

研究了在8—300K温度范围中, Er³⁺/Yb³⁺共掺碲酸盐玻璃的15μm荧光光谱、上转换光谱与温度的关系. Er³⁺:⁴I_13/2→⁴I_15/2跃迁发射光谱通过高斯拟合和简单的四能级系统估计了Er³⁺离子⁴I_13/2和⁴ 关键词： 碲酸盐玻璃 上转换发光 低温 荧光特性     

Er,Yb:YAG微晶玻璃发光特性的研究

高温熔制Er³⁺，Yb³⁺离子掺杂CaO-Y₂O₃-Al₂O₃-SiO₂系统玻璃，并进行微晶化处理，研究了微晶玻璃中Er³⁺离子的发光及上转换发光特性，分析了微晶玻璃上转换发光机理.结果表明：原始玻璃经热处理得到了Er,Yb:YAG微晶玻璃，微晶玻璃中Er³⁺离子在室温下⁴I_13/2→⁴I_15/2跃迁产生横盖1450—1650nm区间的超宽带荧光，荧光半高宽达180nm，这可能由于YAG微晶相中Er³⁺离子与玻璃相中残留Er³⁺离子的共同发光；Er³⁺与Yb³⁺离子局域基质声子能量的降低使微晶玻璃Er³⁺离子上转换发光强度与原始玻璃相比显著提高，绿光、红光上转换荧光强度比玻璃样品分别增强约7和3倍；微晶化后Er³⁺，Yb³⁺离子局域环境发生变化也导致微晶玻璃中Er³⁺离子绿光、红光上转换发光相对强度发生变化. 关键词： 铒 镱:钇铝石榴石 微晶玻璃 荧光光谱     

Optical and electronic polarizability investigation of Nd-doped soda-lime silicate glasses

This paper reports on different physical and optical properties of Nd³⁺-doped soda-lime silicate glass. The glasses containing Nd³⁺ in (65−x)SiO₂:25Na₂O:10CaO:xNd₂O₃ (where x=0.0-5.0 mol%) have been prepared by the melt-quenching method. In order to understand the role of Nd₂O₃ in these glasses the density, molar volume, refractive index and optical absorption were investigated. The results show that the density and molar volume of the glasses increase with an increase in Nd₂O₃ concentration and consequently generate more non-bridging oxygen (NBOs) into glass matrix. The optical absorption spectra were measured in the wavelength range from 300 to 700 nm and the optical band gaps were determined. It was found that the optical band gap decreases with an increase in Nd₂O₃ concentration. On the basis of the measured values of density and refractive index, the Nd³⁺ ion concentration in glasses, the polarizability of oxide ions and optical basicity were theoretically determined.     

Effect of Nd concentration on structural and optical properties of Nd:Y2O3 transparent ceramic

Y₂O₃ transparent ceramics with different Nd concentration (0.1-7.0at%) were fabricated using ZrO₂ as additive. All the samples exhibit high transparency over a broad spectral region. The elements (Y, O and Nd) are uniformly distributed in the ceramic body, and the average grain size increases with Nd content. Based on the absorption spectrum, the Judd-Ofelt intensity parameters are calculated (Ω₂=4.364×10⁻²⁰ cm², Ω₄=3.609×10⁻²⁰ cm² and Ω₆=2.919×10⁻²⁰ cm²). The absorption coefficients increase linearly with Nd³⁺ doping concentration. The absorption cross-section at 804 nm and stimulated emission cross-section at 1078 nm are calculated to be 1.54×10⁻²⁰ and 7.24×10⁻²⁰ cm², respectively. All the emission bands exhibit the highest emission intensities with 1.0at% Nd³⁺ ion content, while the lifetime decreases dramatically from 321.5 μs (0.1at% Nd) to 17.9 μs (7.0at% Nd). According to the emission spectra and measured lifetime, the optimum doping concentration of Nd³⁺ ion in Y₂O₃ transparent ceramic might be around 1.0at%.     

Near-infrared emission bands of Er-doped YAP and LSO crystals

The ground state absorption (GSA), photoluminescence (PL) and photoluminescence excitation (PLE) spectra for Er(1.0 at%):YAP and Er(0.5 at%):LSO were measured at room temperature. Based on the GSA spectra, the radiative transition rates and luminescence branch ratios of erbium ions were determined by the Judd-Ofelt (J-O) method. In the range of 1400-1700 nm Er(1.0 at%):YAP has intense absorption at 1509 nm (0.96×10⁻²⁰ cm²), which is almost two times larger than the peak absorption of Er(0.5 at%):LSO. From the PL and PLE spectra, four intense emission bands around 850 nm (⁴S_3/2→⁴I_13/2), 980 nm (⁴I_11/2→⁴I_15/2), 1230 nm (⁴S_3/2→⁴I_11/2) and 1520 nm (⁴I_13/2→⁴I_15/2) were observed. The stimulated emission cross-sections of the four bands were calculated by the Fuchtbauer-Ladenberg (F-L) equation. The results suggest that Er(1.0 at%):YAP has potential to realize laser oscillation at 858 nm because of the relatively large simulated emission cross-section (1.76×10⁻²⁰ cm²). The temperature dependences of the PL spectra for the two crystals were also investigated in the range of 290-12 K. The ∼1520 nm emission presents continuous increase with temperature, while the emissions around 850, 1230 and 980 nm firstly increase with temperature, then reach their own largest values at the transition temperatures (about 100 K), and finally decrease with temperature. These results were well interpreted by the temperature dependence of multi-phonon process.     

Optical properties of sol-gel fabricated Mn/SiO2 nanocomposites: Observation of surface plasmon resonance in Mn nanoparticles

Manganese nanoparticles were grown in silica glass and silica film on silicon substrate by annealing of the sol-gel prepared porous silicate matrices doped with manganese nitrate. Annealing of doped porous silicate matrices was performed at various conditions that allowed to obtain the nanocomposite glasses with various content of metallic Mn. TEM of Mn/SiO₂ glass indicates the bimodal size distribution of Mn nanoparticles with mean sizes of 10.5 nm and 21 nm. The absorption and photoluminescence spectra of Mn/SiO₂ glasses were measured. In the absorption spectra at 300 nm (4.13 eV) we observed the band attributed to the surface plasmon resonance in Mn nanoparticles. The spectra proved the creation of Mn²⁺ and Mn³⁺ ions in silica glass as well. The absorption spectra of Mn/SiO₂ glasses annealed in air prove the creation of manganese oxide Mn₂O₃. The measured reflection spectra of Mn/SiO₂ film manifest at 240-310 nm the peculiarity attributed to surface plasmons in Mn nanoparticles.     

钕离子掺杂和钕铝共掺高硅氧玻璃的光谱性质研究

基于多孔玻璃烧结的方法制备了钕离子掺杂和钕铝共掺高硅氧玻璃，测量了掺钕高硅氧玻璃的吸收光谱、荧光光谱和荧光寿命. 利用Judd-Ofelt理论计算得到了钕离子在高硅氧玻璃中的强度参数，计算并对比了掺钕高硅氧玻璃和钕铝共掺高硅氧玻璃的理论荧光寿命、受激发射截面和发光量子效率.讨论了钕铝共掺高硅氧玻璃中铝离子的掺入对玻璃发光性质的影响. 通过与其他掺钕氧化物玻璃和一些商用硅酸盐玻璃的主要光谱性质的比较，掺钕高硅氧玻璃显示了较好的光谱性质，有可能成为一种应用于高能和高频激光领域的新型激光材料. 关键词： 掺钕高硅氧玻璃 钕铝共掺 光谱性质 Judd-Ofelt理论     

Ti: LiAlO2新型晶体的结构分析

通过研究提拉法生长的掺杂Ti浓度为0.2at%的LiAlO₂晶体吸收光谱，荧光光谱和红外光谱，来分析此新型晶体的结构.分析发现光谱中仅出现了四价Ti离子的196nm的特征吸收峰, 用235nm光激发得到384nm的特征发射峰；针对吸收光谱中660—820nm出现的四个弱小吸收峰提出了一个色心模型，从而解释了空气和富Li气氛处理后吸收峰消失的现象；对比纯LiAlO₂晶体的红外光谱发现，Ti的掺入仅影响了［AlO₄］键强，而［LiO_{4 关键词： 2}')" href="#">Ti: LiAlO₂ 色心 光谱     

用于S波段放大器的掺铥重金属氧化物玻璃发光性质研究

制备了不同Tm³⁺离子浓度的PbO-Bi₂O₃-Ga₂O₃-GeO₂重金属氧化物玻璃，根据吸收光谱计算了JO强度参量以及Tm³⁺离子在玻璃中的自发辐射概率、荧光分支比及荧光辐射寿命等光谱参数.通过测量1470nm波段发射光谱，计算表明该玻璃系统在S波段有较宽的荧光半高宽和较大的峰值受激发射截面，但玻璃中荧光寿命随稀土离子浓度增加呈线性下降，而交叉弛豫速率随浓度的平方迅速增加.研究结果仍可表明掺铥重金属氧化物玻璃是一种理想的S波段宽带光纤放大器用基质材料. 关键词： 重金属氧化物玻璃 3+离子')" href="#">Tm³⁺离子 S波段光纤放大器 光谱性质     

Structure–property correlations in lead silicate glasses and crystalline phases

Lead silicate glasses containing 40–65?mol% of PbO were prepared at two melt-quenching rates and characterized by X-ray diffraction, UV-Visible absorption spectroscopy, density, microhardness, thermo-mechanical analysis, differential scanning calorimetry and Raman scattering studies. On increasing the PbO concentration, density increases, glass transition temperature decreases and the optical absorption edge shifts towards longer wavelength. An intense optical absorption band was observed just below the absorption edge in glasses with 55?mol% and higher concentration of PbO. Dilatometric measurements show an unusual property that glasses do not show any abrupt increase in volume near the glass transition temperature but transform directly into the liquid state. Raman spectroscopy confirmed that the concentration of SiO₄ tetrahedra containing one or more NBOs increase with PbO mol%. Devitrification studies on lead silicate glasses found that samples with 40–45?mol% of PbO do not crystallize, whereas samples with higher PbO concentration produce multiple crystalline phases like PbSiO₃, Pb₃₃Si₂₄O₈₁, Pb₂SiO₄ and Pb₃Si₂O₇ on heat treatment.