Er3+,Er3+-Yb3+和Er3+-Na+掺杂CaF2透明陶瓷的光学性能（英文）

以Ca(NO3)2、Er(NO3)3、Yb(NO3)3、KF和NaF为原料,采用热压烧结方法制备出Er3+,Er3+-Yb3+和Er3+-Na+掺杂CaF2透明陶瓷。测试了样品室温吸收光谱和发射光谱。利用Judd–Ofelt理论分析了样品的光学性能,并对吸收光谱进行计算拟合,得到光谱参数t(t=2,4,6),根据光谱参数t计算出Er3+某些能级的的跃迁几率、荧光分支比、辐射寿命和品质因子,讨论并比较了Er3+-Yb3+和Er3+-Na+共掺对CaF2透明陶瓷光学性能的影响。结果表明:掺杂Yb3+和Na+改变了Er3+光谱参数;Er3+-Yb3+共掺有利于提高样品的荧光强度;Er3+-Na+共掺有利于提高荧光寿命。     

Er,Yb:CaF2透明陶瓷的制备及其性能研究

首先以(Ca(NO3)2·4H2O、Er(NO3)3·5H2O、Yb(NO3)3·5H2O和KF·2H2O等试剂为原料,选择化学沉淀法合成了Er,Yb:CaF2纳米粉体,采用XRD和FE-SEM技术对纳米粉体特性进行了测试与表征.以合成的纳米粉体为原料,采用真空热压烧结技术,在800℃、30 MPa条件下制备了Er,Yb:CaF2透明陶瓷,并对陶瓷样品的元素组成与分布、显微结构及热导率等特性进行了测试与表征.结果表明:合成的Er,Yb:CaF2纳米粉体为单相立方萤石结构,平均尺寸在20～40 nm,并易形成尺寸为3～5μm的团聚体;Er与Yb元素在陶瓷样品中分布均匀,陶瓷的平均晶粒尺寸为1μm左右,并由于不均匀烧结,样品中存在大尺寸的孔洞结构,随着Yb掺杂浓度的增加,陶瓷样品的热导率逐渐降低.     

基于Er3+/Yb3+掺杂的上转换玻璃陶瓷材料的制备和性能

采用熔融-晶化法在ZnO-Al2 O3-SiO2系玻璃陶瓷的基础上,用GeO2取代部分SiO2成功制备出Er3+/Yb3+共掺ZnO-Al2 O3-GeO2-SiO2系玻璃陶瓷,并通过对样品的硬度及上转换荧光测试分析确定了GeO2的最佳取代量为7.5wt％.研究发现在980 nm波长光的激发下,样品产生了绿色(524 nm、546 nm)和红色(659 nm)上转换发光,且当Er3+/Yb3+掺杂比为2.5:6.5时样品上转换荧光强度最强.     

Yb~(3+)/Ho~(3+)共掺Ge_(25)Ga_5S_(70)玻璃中红外发光特性

用熔融急冷法制备了系列Yb3+/Ho3+共掺Ge25Ga5S70硫系玻璃,测试了样品的吸收光谱以及980nm激光泵浦下中红外荧光光谱特性,用Judd–Ofelt理论计算分析了单掺Ho3+在Ge25Ga5S70玻璃中的强度参数Ωi(i=2,4,6)、自发辐射跃迁几率、荧光分支比和辐射寿命等光谱参数。研究了Yb3+/Ho3+共掺样品在980nm激光泵浦下获得的Ho3+:2.9μm中红外荧光光谱性质,表明Yb3+/Ho3+之间存在能量共振转移。当固定Yb3+掺杂浓度为0.5%(质量分数,下同),随着Ho3+掺杂浓度从0增加为0.7%,Yb3+:2F5/2能级寿命明显单调下降,说明Yb3+/Ho3+之间有效的能量传递主要来源于Yb3+:2F5/2能级向Ho3+:5I6能级的共振能量传递。运用Futchbauer-Ladenburg公式计算比较了不同掺杂浓度下Ho3+:5I6→5I7跃迁的受激发射截面。     

Er3+掺杂TeO2-WO3-ZnO玻璃的发光性质

制备了不同组成和掺Er3 量的TeO2 WO3ZnO(TWZ)玻璃样品 ,测量了样品的吸收光谱和 970nmLD激发下的荧光光谱、荧光寿命。对制得的Er2 O3掺杂摩尔分数为 0 .6%的玻璃样品 ,由吸收光谱测得的 1.5 μm峰值吸收截面及计算的受激发射截面分别为 0 .74～0 .77pm2 和 0 .86～ 0 .90pm2 ,且玻璃的组成对其影响很小 ;Er3 在摩尔组成为 75TeO2 2 0WO35ZnO的TWZ玻璃中具有较大的荧光发射半高宽 (fullwidthathalfmaximum ,FWHM) ,且随掺Er3 量的增加 ,Er3 1.5 μm发射荧光强度和FWHM总体呈增加趋势 ,实验得到掺Er3 量为 3 .3 4× 10 2 0 /cm3时的FWHM为 80nm。研究同时发现Er3 在TWZ玻璃中具有很好的溶解性且其浓度猝灭效应较小     

Er3+和Yb3+共掺锗硅酸盐玻璃的上转换发光性能

采用熔融-淬火法制备了基体为30SiO2-20GeO2-15Al2O3-5B2O3-30CaF2的Er3+和Yb3+共掺锗硅酸盐玻璃.采用X射线衍射仪、荧光光谱仪和热分析仪对样品进行了表征.结果表明:Er2O3含量从0.5％(摩尔分数,下同)增加到2.0％时,玻璃转变温度Tg和Tx-Tg(Tx为第一析晶温度)数值均有明显下降.Yb2O3含量从1.5％增加到4.5％时,玻璃上转换红光发光强度数量级由103提高到105,对其中1个样品在740℃热处理12h后发现,微晶化处理并未对Er的上转换发光产生有益影响.     

Er3+:Yb3+:Y3Al5O12单晶中Er3+离子光谱参数的计算

采用提拉法生长出光学质量的Er3 :Yb3 :Y3Al5O12(YAG)单晶,测定了晶体的吸收光谱和上转换荧光光谱,根据Judd-Ofelt理论,计算出Er3 在YAG晶体中的强度参数Ω2=1.074 1×10-20cm2,Ω4=1.295 3×1020cm2,Ω6=0.923 8×1020cm2.由此得到部分波段跃迁的荧光分支比、辐射寿命和积分发射截面积.提出将679 nm波段的4F9/2→4I15/2跃迁作为激光输出进一步研究的新通道.     

掺Yb3+的氧化镧钇透明激光陶瓷的光谱特性

采用传统陶瓷烧结工艺,在无压还原气氛中低温制备了Yb3 掺杂量高达10%(按摩尔计)的透明性良好的氧化镧钇激光陶瓷,研究了其在室温的吸收光谱、发射光谱以及荧光寿命.结果表明:掺Yb3 氧化镧钇透明激光陶瓷具有宽的吸收和发射光谱以及长的荧光寿命.吸收峰位于902,942nm和968nm处,吸收截面分别为0.31×10-20,0.45×10-20cm2和0.53×10-20cm2;主发射峰位于1 032nm和1 075 nm处,发射截面分别为1.05×10-20cm2和0.87×10-20 cm2,上能级荧光寿命分别为1.17ms和1.04ms.掺Yb3 氧化镧钇透明激光陶瓷大的吸收和发射截面以及长的荧光寿命有利于高效吸收泵浦能量,是一种适合于高效、高功率激光二极管泵浦的固体激光介质.     

Yb3+和Ce3+对Er3+掺杂碲酸盐玻璃光谱性质的影响

;在掺Er3 的70TeO2-20ZnO-5La2O3-5Nb2O5(各组成以摩尔比计)玻璃中引入Yb3 和Ce3 ,分析比较了975nm泵浦下Yb3 和Ce3 对于Er3 的1.5μm波段红外荧光和可见上转换发光特性的影响.结果表明:在掺Er3 的碲酸盐玻璃中引入Yb3 ,有效地提高了Er3 的1.5μm波段红外荧光强度、展宽了其荧光谱,也显著增强了可见上转换发光强度.随着玻璃中Ce3 的引入,进一步提高了Er3 的4I11/2→4I13/2能级间无辐射弛豫速率,1.5μm波段红外荧光也得到进一步增强,但可见上转换发光大幅减弱.与Er3 /Yb3 共掺相比,Er3 /yb3 /Ce3 共掺碲酸盐玻璃是一种更为理想的应用于1.5 μm波段宽带放大器的增益介质.     

Spectroscopic Properties and Energy Transfer Mechanism of Er^3＋/Yb^3＋/Ce^3＋ Codoped Tellurite-based Glasses

为进一步揭示多稀土离子共掺低声子能量玻璃中Er3＋的光谱特性及其发光机理,采用高温熔融法制备了Er3＋/Yb3＋/Ce3＋共掺组分为（72.5–x）TeO2–20ZnO–5La2O3–0.5Er2O3–2Yb2O3–xCe2O3（x=0,0.4,0.7,1.0,摩尔分数x%）的碲酸盐玻璃,通过测量吸收光谱、荧光光谱和无掺杂样品的Raman光谱,以及计算相应能级间的吸收截面和受激发射截面,研究并分析了Yb3＋和Ce3＋离子掺杂对于Er3＋的1.55μm波段荧光特性的影响。结果显示：Yb3＋和Ce3＋的引入能显著增强975nm泵浦下Er3＋的1.55μm波段荧光强度。分析表明：Er3＋在1.55μm波段荧光强度的增强主要归结于Yb3＋/Yb3＋、Yb3＋/Er3＋离子间的共振能量传递过程以及基于单声子和双声子辅助的Er3＋/Ce3＋离子间的能量传递过程,并通过计算得到了相应稀土离子间的能量传递微观参数和声子所作的贡献比。     

Er3+ cross-section spectra of Er3+/Pr3+:Gd3Ga5O12 single-crystal: Pr3+-codoping effect

Fluorescence and absorption spectra at 530 nm (²H_11/2→⁴I_15/2), 560 nm (⁴S_3/2→⁴I_15/2), 660 nm (⁴F_9/2→⁴I_15/2), 980 nm (⁴I_11/2→⁴I_15/2), 1530 nm (⁴I_13/2→⁴I_15/2), and 2710 nm (⁴I_11/2→⁴I_13/2) of Er³⁺ in Gd₃Ga₅O₁₂ single-crystal codoped with Pr³⁺ have been measured. Judd-Ofelt analysis yields the intensity parameters Ω₂ = (0.68 ± 0.03) × 10⁻²⁰ cm², Ω₄ = (0.60 ± 0.07) × 10⁻²⁰ cm², and Ω₆ = (0.90 ± 0.17) × 10⁻²⁰ cm². A comparison with previously reported values of Er³⁺-only doping case shows that Pr³⁺-codoping causes slight change of both Ω₂ and Ω₄, while onefold increase of Ω₆. From calculated radiative rates and measured fluorescence spectra, Er³⁺ emission cross-section spectra were calibrated at first. Then, the absorption cross-section spectra were calculated using McCumber relation. In parallel, the absorption cross-section spectra were also obtained from the measured absorption spectrum, and compared with those obtained from the McCumber relation. The comparison shows that both methods give consistent result of absorption cross-section spectrum. Further comparison with Er³⁺-only doping case shows that Pr³⁺-codoping causes considerable change of Er³⁺ cross-section value. In spectrally mixing regions of Er³⁺ and Pr³⁺, Pr³⁺ emission affects little the determination of Er³⁺ emission cross-section as Pr³⁺ fluorescence is much weaker than Er³⁺ fluorescence due to low Pr³⁺ concentration.     

Luminescent Er3+ doped transparent alumina ceramics

We report on successful preparation of Er³⁺ doped transparent alumina (0.1–0.17 at.%) exhibiting visible light photoluminescence using wet shaping method and hot isostatic pressing. The effects of dopant amount, type of doping powder and powder pre-treatment on final microstructure, real in-line transmittance and photoluminescence characteristics were studied.The real in-line transmittance ranged between 28 and 56%, depending on processing parameters. The transparency decreased with increased amount of dopant. The decrease is dependent on the type of doping powder and its pre-treatment.The photoluminescence spectra measured in both visible and NIR region showed typical emission bands due to the presence of Er³⁺ ions. The decay profiles of the ⁴S_3/2 → ⁴I_15/2 transition were fitted with a 2-exponential function, with faster component in the range of 360–700 ns and slower component around 1.6-2.4 μs. The intensity of emissions and lifetime of the ⁴S_3/2 level decrease significantly with increasing concentration of Er³⁺ ions.     

Multifunctional optical thermometry based on the stark sublevels of Er3+ in CaO-Y2O3: Yb3+/Er3+

A conventional high temperature solid state method was utilized to prepare CaO-Y₂O₃, which is a potential candidate for manufacturing crucible material to melt titanium and titanium alloys with low cost. Meanwhile, Yb³⁺ ions and Er³⁺ ions were selected as the sensitizers and activators respectively to dope into CaO-Y₂O₃, aimed at providing real-time optical thermometry during the preparation process of titanium alloys realized using fluorescence intensity ratio (FIR) technology. The results reveal that a high measurement precision can be acquired by using the Stark sublevels of Er^{3+ 4}F_9/2 to measure the temperature with a maximum absolute error of only about 3 K. In addition, by analyzing the dependence of ⁴I_13/2 → ⁴I_15/2 transition on pump power of 980 nm excitation wavelength, it was found that the laser-induced thermal effect has almost no influence on the temperature measurement conducted by using the FIR of the Stark sublevels of Er^{3+ 4}I_13/2, which means that a high excitation pump power can be used to obtain strong NIR emission and good signal-to-noise ratio for optical thermometry without the influence of the laser-induced thermal effect. All the results reveal that CaO-Y₂O₃: Yb³⁺/Er³⁺ is an excellent temperature sensing material with high measurement precision.     

Abnormal upconversion luminescence induced by defects and Er3+–Yb3+ distance change in Cs3GdGe3O9:Er3+/Yb3+ phosphors

A series of Er³⁺/Yb³⁺ co-doped Cs₃GdGe₃O₉ (CGG) phosphors were prepared by solid-phase sintering method, and the microstructure and upconversion luminescence (UCL) properties were tested by variable-temperature X-ray diffractometry and variable-temperature spectrometer. Abnormal UCL phenomena were found, which include UCL intensity continuously increasing under 980 nm laser continuous irradiation and UCL thermal enhancement. After 10 min of continuous irradiation by 980 nm laser at 513 K, the UCL intensity increased 2.91 times compared with the initial UCL intensity. The phenomenon is due to the electron releasing of host defects. The green UCL intensity of CGG:0.1Er³⁺/0.2Yb³⁺ decreases at 303–423 K and increases at 423–723 K, which reaches 13.23 times compared with that at 423 K. The phenomenon is due to Er³⁺–Yb³⁺ distance change by temperature and phonon-assisted transitions. In addition, the absolute temperature sensitivities of samples are calculated by luminescence intensity ratio technology, the maximum absolute sensitivity of CGG:0.1Er³⁺/0.4Yb³⁺ is 0.00691 K⁻¹ at 546 K, and the maximum relative sensitivity of CGG:0.1Er³⁺/0.1Yb³⁺ is 0.01224 K⁻¹ at 303 K. These results indicate that CGG:Er³⁺/Yb³⁺ phosphors can be used as a high-temperature optical thermometer.     

Optical properties of Er3+ and Yb3+/Er3+-doped NaF-Na2SO4-Al(PO3)3 fluoro-sulfo-phosphate glasses

Fluoro-sulfo-phosphate (FPS) glass is of current interest as potential material for laser application due to its good glass-forming ability, thermal, and chemical stability as well as the complicated local environment for incorporated species. Herein, the physical and luminescent properties of Er³⁺ and Yb³⁺/Er³⁺-doped FPS glasses vs S/F ratio are investigated comprehensively. The low melting temperature (750°C) leads to fewer ingredients evaporation and easier operation. The sulfate addition depolymerizes the structure of FPS glasses, leading to either monotonic or nonmonotonic variations of physical properties, while no deterioration in thermal and limited one in chemical stability is caused. The addition of sulfate also modifies the local structure around optical active species and thus, leading to higher emission cross section (1.52 × 10⁻²⁰ cm²), effective linewidth (68.4 nm), figure of merit (5.61 × 10⁻²³ s cm²), gain bandwidth (102.44 × 10⁻²⁷ cm³), and energy-transfer microparameters (51.87 × 10⁻³⁹ cm⁶/s), implying high possibility to serve as 1.5 μm laser application.     

Er3+-Yb3+ ions doped fluoro-aluminosilicate glass-ceramics as a temperature-sensing material

The transparent Er³⁺-Yb³⁺-doped fluoro-aluminosilicate glass-ceramic (GC) was prepared by melt-quenching. The crystal phase, morphology, and up-conversion (UC) luminescence of as-produced GC were characterized by X-ray diffraction, scanning electron microscopy, and fluorescence spectrophotometry, respectively. The results show that BaYF₅ nanocrystals were uniformly distributed in the glass matrix of the as-produced GC. When the as-produced GC was subjected to heat treatment, the crystallinity was increased, but the crystal identity remains unchanged. Such heat-treatment doubled the intensity of the UC luminescence, and this enhancement was ascribed to the increased incorporation of both Er³⁺ and Yb³⁺ ions into the lower phonon energy environment of BaYF₅ nanocrystals. Furthermore, the heat-treated GC was stable against further crystallization, and consequently its UC luminescence was stable at the application temperature. The heat-treated GC was found to possess an outstanding temperature-sensing capability.     

Er~(3+)-Tm~(3+)共掺碲酸盐玻璃中近红外超宽带发光性质

研究了Er~(3+)-Tm~(3+)共掺TeO_2O-Nb_2O_5-Ln_2O_3(TKNL)碲酸盐玻璃的近红外发光光谱以及上转换光谱性质,该碲酸盐玻璃的起始析晶温度与玻璃转变温度之差△T为136℃,表明此玻璃具有良好的热稳定性,有利于拉制光纤。在808 nm半导体激光器的激发下在近红外波段观察到半高宽为185 nm的宽带近红外发光。通过对不同Tm~(3+)浓度以及不同激发波长下TKNL玻璃的近红外发光以及上转换发光的研究,探讨了Er~(3+)m~(3+)之间的能量传递机理。上述玻璃材料有望用作S和C波段光纤放大器的增益介质。     

Effects of Er3+ concentration on down-/up-conversion luminescence and temperature sensing properties in NaGdTiO4: Er3+/Yb3+ phosphors

Usually, Er³⁺ doping concentration effect on the temperature sensing properties of Er³⁺ containing materials is ignored. In this work, we demonstrated the influence of Er³⁺ concentration and excitation path on the spectral and temperature sensing properties in Er³⁺, Yb³⁺ co-doped NaGdTiO₄ system. The NaGdTiO₄: Er³⁺/Yb³⁺ phosphors were prepared by a high temperature solid state reaction method. Different spectral patterns for down- and up-conversion processes were observed and ascribed to the different excitation and population routes. The concentration quenching behaviors for down- and up-conversion processes were explained via cross relaxations between Er³⁺ ions. Most importantly, the Er³⁺ concentration dependent optical temperature sensing performance was observed and experimentally explained as a fact that the optical transition rate of Er³⁺ in different samples was changed with various Er³⁺ doping concentration.