二氧化硅对铒/铈共掺碲酸盐玻璃光谱性质的影响(英文)

为进一步提高Er3+1.53μm波段的光谱特性,在Er3+:4 I11/2→4 I13/2和Ce3+:2 F5/2→2 F7/2跃迁间存在能量失配(1 400cm-1附近)的Er3+/Ce3+共掺碲酸盐(TeO2-Bi2O3-TiO2)玻璃中引入了高声子能量SiO2组分。测试分析了不同SiO2组分含量下的Er3+吸收光谱、上转换发光谱、1.53μm波段荧光谱、荧光寿命、放大品质因子和玻璃样品的热性能。结果表明:由于增强的Er3+/Ce3+离子间能量传递,当玻璃样品中SiO2含量达到9%(摩尔分数)时,Er3+的1.53μm波段荧光强度得到显著提高。同时,荧光半高宽随SiO2组分含量相应展宽,而玻璃热稳定性随之提高。     

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.     

Yb3+/Er3+共掺碲钨酸盐玻璃的能量传递与频率上转换发光

在970nm LD激发和Er^3 离子浓度几乎不变情况下，研究了Yb^3 ／Er^3 共掺碲钨酸盐玻璃中的能量传递和其上转换发光特性。结果表明：随掺Yb^3 浓度的增加，Yb^3 ／Er^3 间能量传递效率也增加，其值在0．52到0．60之间。在Yb^3 ／Er^3 共掺碲钨酸盐玻璃中观察到峰值分别位于533，547nm和668nm的上转换绿光和红光，它们分别来源于Er^3 离子^2H11/2→^4I15／2(533nm)，^4S3／2→^4I15／2(547nm)和^4F9/2→^4I15／2(668nm)辐射跃迁。上转换红光和绿光均为双光子过程，且随Yb^3 离子掺杂浓度的增加，上转换红绿光强度和其强度比值Ic／Ig也增加，这被认为是与激发态Er^3 与激发态Yb^3 之间的能量传递过程有关。     

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。     

Synthesis and Optical Properties of Er^3＋-Doped CaF2 Nanopowder

采用直接沉淀法制备掺铒氟化钙（Er3＋：CaF2）纳米粉体,通过 X 射线衍射仪、场发射扫描电子显微镜、透射电镜、分光光度计和电感耦合等离子发射光谱仪等分析手段研究了不同反应溶液浓度对 Er3＋：CaF2纳米粉体结构、形貌、粒径和 Er3＋真实掺入量的影响。结果表明：随着反应溶液浓度的增大,粉体颗粒尺寸逐渐减小,团聚程度加剧,Er3＋的真实掺入量逐渐减少。反应溶液浓度为 0.5mol/L 时合成粉体分散性最好,颗粒平均尺寸约为32 nm,有利于制备性能优异的 Er3＋：CaF2透明陶瓷。在 978 nm 激光二极管激发下,该粉体实现了绿色（530～550 nm）和红色（650～660 nm）两种上转换发光,与之对应的 Er3＋辐射跃迁分别属于2H11/2、4S3/2→4I15/2和4F9/2→4I15/2,相对绿光而言红光发射强度较强     

Ho~(3+)/Yb~(3+)共掺TeO_2-ZnO-ZnX_2(X=F,Cl,Br)玻璃的结构和红外发光特性(英文)

采用熔融法制备TeO2-ZnO-ZnX2(X=F,Cl,Br)系统氧卤玻璃块体,并测定了玻璃的各项特征温度。通过Raman光谱和X射线光电子能谱分析了卤化物的引入对玻璃网络结构稳定性的影响。结果表明,加入ZnF2比加入ZnCl2或ZnBr2对Ho3+/Yb3+共掺的碲酸盐玻璃的近红外荧光输出有更明显的效果和规律性。与加入ZnCl2和ZnBr2相比,加入ZnF2对Ho3+/Yb3+共掺的碲酸盐玻璃近中红外的荧光输出影响更加明显和规律。ZnF2虽会抑制1μm处发光但能增强1.2和2μm的发光,同时2μm处荧光输出的量子效率也得到大幅提升。比起使用ZnBr2,使用ZnF2和ZnCl2替代ZnO能更好地提高玻璃的光学性能和热稳定性。在这3种卤化锌中,氟化锌对稀土发光的增强起着更为重要的作用。     

铒/镱共掺硼酸钙镧晶体的生长和光谱性质

在CaO-Li2O-B2O3助熔体系中,生长了掺铒和镱的硼酸钙镧(Er3 :Yb3 :La2CaB10O19,Er:Yb:LCB)晶体.Er:Yb:LCB晶体中Er3 ,Yb3 的分凝系数分别为0.50,0.25.X射线衍射分析表明:Er:Yb:LCB和LCB具有相同的晶体结构.Er:Yb:LCB晶体的熔点大约为1046℃.Er:Yb:LCB晶体的吸收光谱和荧光光谱的测试结果表明:与Er:LCB相比,Er:Yb:LCB晶体在970 nm的吸收系数显著提高,在1 531 nm的发射强度也显著增强,其荧光寿命为0.48 ms.     

Growth and Spectral Analysis of Pr^3＋-Doped KYb（WO4）2 Laser Crystal

以 K2W2O7为助熔剂,采用泡生法生长出了 Pr3＋掺杂量为 5% （摩尔分数）的 KYb（WO4）2（Pr：KYbW）自激活激光晶体。X 射线衍射分析表明：生长的晶体为单斜晶系的 Pr：KYbW,晶格常数为 a = 1.065 nm、b = 1.031 nm、c = 0.753 nm、β = 130.65°。由样品的 Raman 光谱和红外光谱确认 Pr：KYbW晶体内共有 WO6和 YbO8两种畸变多面体结构,验证了晶体中钨氧桥键的存在。吸收光谱表明：在 945、975nm 处出现了 2 个最强的吸收峰,对应于Yb3＋的2F7/2→2F5/2能级跃迁。晶体的上转换荧光谱表明：在 481nm 处的蓝光来自于 Pr3＋的3P0→3H4能级跃迁;在 645nm 处的红光来自于 Pr3＋的3P0→3F2能级跃迁。     

Ho3+/Yb3+掺杂铋镓酸盐光学玻璃的上转换发光

制备了高折射率Ho3 /Yb3 掺杂铋镓酸盐玻璃,用Brewster原理测量玻璃的折射率为2.296.用倒易法计算Yb3 的发射截面面积为2.109×10-20 cm2.在室温,用974nm激光器激发玻璃样品,观察并记录到强烈的双光子上转换荧光.分析认为:铋镓酸盐玻璃中Yb3 直接敏化Ho3 的上转换发光的激发机理是Yb3 到Ho3 的高效能量传递.上转换过程中红光相对强度较强的原因为:玻璃声子能量特性、最大能量声子密度降低和玻璃绿光区强吸收3方面因素增加了5F5能级上的粒子数布居,使5F5→5I8能级的跃迁几率升高,导致红光强度大于绿光强度.     

Gd3+/Ce3+对Tb3+掺杂氟氧化物玻璃发光敏化作用的影响

本文采用高温熔融法制备了Gd/Tb、Gd/Ce、Gd/Ce/Tb掺杂的SiO₂-B₂O₃-BaF₂组分氟氧化物玻璃,通过测试X射线衍射光谱确定了其物相,通过测试其不同波段激发下的荧光光谱研究了不同Gd₂O₃掺量下Tb³⁺的发光性能,并确定了Gd₂O₃更精确的最佳掺量范围。此外,文中通过改变气氛制备了Gd/Ce/Tb共掺杂氟氧化物玻璃,对比研究了Gd³⁺和Ce³⁺对Tb³⁺的敏化作用。结果表明,本文所制备的氟氧化物玻璃都呈稳定的玻璃态;Gd³⁺和Ce³⁺对Tb³⁺的发光都具有敏化作用,且Gd₂O₃掺量为7%(摩尔分数,下同)时敏化效果相较于其他掺量最为显著,超出7%则造成猝灭;Ce₂O_3<...     

Spectroscopic Properties and Thermal Stability of Er3+-Doped Germanotellurite Glasses for Broadband Fiber Amplifiers

The thermal stability and spectroscopic properties of Er₂O₃-doped TeO₂–GeO₂–ZnO–Na₂O–Y₂O₃ glasses for 1.5 μm fiber amplifiers were investigated. The thermal stability of the 75TeO₂·20ZnO· 5Na₂O glass was improved by introducing GeO₂ and Y₂O₃. The radiative transition and the nonradiative transition have a dominant influence on the ⁴I_13/2 level lifetime of Er³⁺ in high- and low-GeO₂ regions, respectively. Adding Y₂O₃ increases the ⁴I_13/2 level lifetime of Er³⁺ significantly. The Judd–Ofelt (J-O) parameter Ω₆ shows a strong correlation with the 1.5 μm emission bandwidth; and the larger the Ω₆, the wider the bandwidth.     

Vibrational Spectra of Water- and Ammonium-Chloride-Related Residues and Upconversion Fluorescence of Er3+ in ZnCl2-Based Glasses

Chloride glasses of the ZnCl₂ and 20KCl-20BaCl₂-60ZnCl₂-0.5ErCl₃ systems were prepared using NH₄Cl as a dehydrating and chlorinating agent, under the melt-quenching method. Water- and ammonium-chloride-related residues in ZnCl₂ glasses were investigated by infrared and near-infrared absorption spectra. Water, Zn—OH, ClO, ClO₂⁻, Zn²⁺-coordinated water, free NH₃, NH₄⁺, and Zn²⁺-coordinated NH₃ were identified in ZnCl₂ glasses. 20KCl-20BaCl₂-60ZnCl₂-0.5ErCl₃ glasses prepared by melting at 500°C for 20 min, under reduced pressure, contained the smallest amounts of water, Zn—OH, and Zn²⁺-coordinated NH₃ and showed strong Er³⁺ upconversion fluorescence.     

Spectroscopic Properties of Er3+-Doped Na2O–La2O3–Al2O3–SiO2 Glasses

Er³⁺-doped sodium lanthanum aluminosilicate glasses with compositions of (90− x )(0.7SiO₂·0.3Al₂O₃)· x Na₂O·8.2La₂O₃· 0.6Er₂O₃·0.2Yb₂O₃·1Sb₂O₃ (in mol%) ( x = 12, 20, 24, 40, 60 mol%) were prepared and their spectroscopic properties were investigated. Judd–Ofelt analysis was used to calculate spectroscopic properties of all glasses. The Judd–Ofelt intensity parameter Ω _t ( t = 2, 4, 6) decreases with increasing Na₂O. Ω₂ decreases rapidly with increasing Na₂O while Ω₄ and Ω₆ decrease slowly. Both the fluorescent lifetime and the radiative transition rate increase with increasing Na₂O. Fluorescence spectra of the ⁴ I _13/2 to ⁴ I _15/2 transition have been measured and the change with Na₂O content is discussed. It is found that the full width at half-maximum decreases with increasing Na₂O.     

Optical properties of Er3+/Yb3+ co-doped phosphate glass system for NIR lasers and fiber amplifiers

In this research, the optical properties of Er³⁺/Yb³⁺ co-doped phosphate glass have been studied to explore the potential of this glass system in laser and electronic amplifiers. The Judd–Ofelt (J-O) intensity parameter (Ω_t) in the J-O model was established to determine the absorption intensity of the glass. The optical properties of the glass can be evaluated by various radiation parameters such as the radiative transition probabilities (A_rad), stimulated emission cross sections (σ_e), branching ratios (β_JJ'), maximum half-width values (Δλ_p), and the radiation lifetime (τ_rad) of the glass. It was found that in the case of Yb³⁺ as a sensitizer, the spectral properties of the Er³⁺ doped glass can be maximized. The data of A_rad, β_JJ', τ_rad, σ_e and Δλ_p obtained by Er³⁺/Yb³⁺ co-doping can find that the Er³⁺-doped sample undergoes ⁴I_13/2–⁴I_15/2 transition at 1.56?µm, and the stimulated emission cross section is greatly improved. The application prospects of the glass in solid near-infrared laser and electronic communication was discussed. According to the comprehensive discussion and analysis, the glass has great application potential.     

Pr3+/Er3+ Codoped Ge-As-Ga-S Glasses as Dual-Wavelength Fiber-optic Amplifiers for 1.31 and 1.55 μm Windows

Fluorescence emissions at both 1.31 and 1.55 μm communication windows were observed from Pr³⁺/Er³⁺ codoped Ge-As-Ga-S glasses with a single wavelength pumping at 986 nm. The lifetime of the Er³⁺:⁴ I _11/2 level decreased as the Pr³⁺ concentration increased, and that of the Pr³⁺:¹ G ₄ level increased as the Er³⁺ concentration increased. Energy transfer from the Er³⁺:⁴ I _11/2 level to the Pr³⁺:¹ G ₄ level was responsible for emission of the 1.31 μm fluorescence from the Pr³⁺:¹ G ₄ level. Ge-As-Ga-S glasses that have been doped with Pr³⁺ and Er³⁺ cations are promising amplifier materials for both 1.31 and 1.55 μm communication windows.     

Energy Transfer and Population Inversion in Heavy Metal Oxide Glasses Doped with Tm3+ and Tb3+

Emission properties and energy transfer of PbO–Bi₂O₃–Ga₂O₃–GeO₂ glasses codoped with Tm³⁺ and Tb³⁺ ions were investigated. The 1.48-μm emission due to the Tm³⁺:³H₄→³F₄ transition can be used to amplify the S-band (1460–1530-nm) signal light. With Tb³⁺ addition, the lifetime and emission intensity of the Tm³⁺:³F₄ level decreased sharply via the Tm³⁺:³F₄→Tb³⁺:⁷F_0,1,2 energy transfer. Population densities of the ³F₄ and ³H₄ levels in Tm³⁺ calculated from rate equations clearly verified that population inversion in Tm³⁺ ions became possible with as little as 0.1 mol% of Tb³⁺ addition.     

Dispersion and Upconversion Fluorescence of Nd3+ Ions in Zinc Chloride-Based Glasses

Nd³⁺-ion-doped ZnCl₂-based glasses were prepared via the melt-quenching method. The Nd³⁺-ion upconversion excitation mechanism and the ability to disperse Nd³⁺ ions into ZnCl₂-based glasses were investigated using absorption and upconversion fluorescence spectra of Nd³⁺ ions. The ZnCl₂-based glass that had an average cationic radius equal to the ionic radius of Nd³⁺ (98 pm) had the greatest ability to disperse Nd³⁺ ions. The 20KCl·25BaCl₂·55ZnCl₂glass, which had the average cationic radius nearest to 98 pm, dispersed Nd³⁺ ions the most, and it had the strongest upconversion fluorescence.     

Energy Transfer Process for the Blue Up-Conversion in Calcium Aluminate Glasses Doped with Tm3+ and Nd3+

Excitation of Tm³⁺ to ³ H ₄ using the 791 nm pump source showed the frequency up-converted blue emission (∼480 nm) due to the Tm³⁺:¹ G ₄→³ H ₆ transition in Tm³⁺/Nd³⁺ codoped CaO·Al₂O₃ glasses. Intensity and lifetime changes with rare-earth concentrations suggested the efficient energy transfer of Tm³⁺:³ H ₄→ Nd³⁺:⁴ F _5/2 and Nd³⁺:⁴ F _3/2→ Tm³⁺:¹ G ₄. The latter transfer enabled Tm³⁺ to reach its ¹ G ₄ level, and the blue emission became possible through the ¹ G ₄→³ H ₆ transition. Quantitative analysis with rate equations proved that these two transitions were the most efficient among all the possible energy transfer routes between Tm³⁺ and Nd³⁺. Calculated up-conversion efficiency of the Tm³⁺/Nd³⁺ combination in CaO·Al₂O₃ glass was 6.6 × 10⁻³, and it was ∼4 orders of magnitude larger than those reported for other oxide glasses.     

Tb3＋自敏化效应与Gd3＋-Tb3＋能量转移对硅酸盐玻璃发光性能的影响

研究了Tb3+自敏化效应与Gd3+-Tb3+能量转移对硅酸盐玻璃发光性能的影响.结果表明,随着Tb3+掺杂量的增加,Tb3+的400～450 nm蓝色荧光发射减弱,而485 nm和545 nm绿光发射增强.Tb3+掺杂硅酸盐玻璃中,Tb3+之间存在能量转移,产生自敏化效应,这种转移是由Tb3+之间电偶极-电四极的相互作用引起的共振能量转移.Gd3+通过Gd3+-Tb3+间的能量转移对Tb3+的发光起敏化作用,这种能量转移主要是偶极与偶极相互作用引起的共振转移.