混合形成体对掺铒碲酸盐玻璃的热力学稳定性和发光性能的影响

研究了混合形成体效应对掺铒碲酸盐玻璃热力学稳定性、1.53 μm发光特性和上转换发光强度的影响.通过拉曼光谱测试,分析了WO₃,Nb₂O₅,GeO₂等氧化物对Er³⁺离子配位场结构,以及对发光谱的非均匀展宽机理的作用.结果表明,通过掺杂适当声子能量的网络形成体氧化物,不但可获得热力学稳定性较好的玻璃,还可有效降低Er³⁺离子⁴I_11/2能级的寿命,在抑制Er³⁺离子在可见光波段的上转换发光的同时不致劣化其在1.53 μm的发光特性.本文制得的碲酸盐玻璃具有较大的受激发射截面((9.64—10.96)×10^-21cm²)和荧光半高宽(FWHM)(50—67 nm),热力学稳定性良好,是一种理想的掺Er³⁺宽带有源光纤用基质玻璃. 关键词： 掺铒碲酸盐玻璃 混合形成体 1.53 μm发光 声子能量     

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}     

GeO2含量对掺铒锗碲酸盐玻璃物性和光谱特性的影响

本文研究了x GeO₂-(70-x)TeO₂-5K₂O-5Na₂O-10Nb₂O₅-10ZnO-0.2Er₂O₃(x=0,10, 25, 50, 70(摩尔百分数))玻璃的物性和光谱特性，讨论GeO₂含量对锗碲酸盐玻璃物性和光谱特性的影响.研究发现：GeO₂的加入提高了碲酸盐玻璃热稳定性， 关键词： 锗碲酸盐玻璃 玻璃热稳定性 荧光     

Yb3+敏化的Er3+/Ho3+共掺碲酸盐玻璃的上转换发光研究

用高温熔融法制备了系列Er³⁺/Yb³⁺共掺，Ho³⁺/Yb³⁺共掺，和Er³⁺/Yb³⁺/Ho³⁺三掺碲酸盐玻璃，在975nm激光抽运下三种掺杂玻璃中都出现了较强的绿光和红光上转换.研究了Yb³⁺离子对Er³⁺和Ho³⁺离子上转换发光强度的影响以及Yb³⁺→Er关键词： 3+/Yb³⁺/Ho³⁺共掺')" href="#">Er³⁺/Yb³⁺/Ho³⁺共掺 碲酸盐玻璃 光谱性质 上转换     

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     

一种新型掺铒碲酸盐玻璃的光谱性质研究

研究了一种新型掺Er³⁺碲酸盐玻璃的光谱性质；应用Judd-Ofelt理论计算了碲 酸盐玻璃中Er³⁺离子的强度参数Ω(Ω₂=479×10^-20 cm²,Ω₄= 152×10^-20cm²,Ω₆=066×10^-20cm2)，计算了离子的自发跃迁概 率，荧光分支比；应用McCumber理论计算了Er³⁺的受激发射截面(σ_{e=1040×1 0^-21cm²)，Er³⁺离子⁴I13/ 2→⁴I15/2发射谱的 荧光半高宽(FWHM=655nm)及各能级的荧光寿命(⁴I13/2 能级为τrad =399ms)；比较了不同基质玻璃以及不同类型碲酸盐玻璃中Er³⁺离子的光谱 特性， 结果表明该掺铒碲酸盐玻璃具有更好的光谱性能，更适合于掺Er³⁺光纤放大 器实现宽带和高增益放大. 关键词： 碲酸盐玻璃 光谱性质 Judd-Ofelt理论}     

Er3+/Ce3+共掺TeO2-Bi2O3-TiO2玻璃的热稳定性和光谱特性研究

用高温熔融法制备了Er³⁺/Ce³⁺共掺新型碲酸盐玻璃(TeO₂-Bi₂O₃-TiO₂).采用差热分析方法研究了玻璃的热稳定性,测试并分析了不同Ce³⁺离子掺杂浓度下Er³⁺离子的吸收光谱、上转换光谱和荧光光谱特性.研究结果表明,制备的碲酸盐玻璃具有很好的热稳定性,玻璃析晶温度Tx与玻璃转变温度Tg之差(ΔT=Tx-Tg)达到了185 ℃,高于其它文献的报道|同时,Ce3+离子共掺引入的能量转移(Ce³⁺∶2F5/2+Er³⁺∶4I11/2→Ce³⁺∶2F7/2+Er³⁺∶4I13/2)有效地抑制了Er³⁺离子上转换发光并显著增强了1.53 μm波段荧光强度,而发射截面随着Ce³⁺离子掺杂浓度相应增大.优异的热稳定性以及光谱性能揭示Er³⁺/Ce³⁺共掺碲酸盐玻璃是一种潜在的制备宽带掺铒光纤放大器的理想增益介质.     

WO3对掺铒碲酸盐玻璃光谱性质的影响

制备了掺铒碲钨酸盐玻璃(80-x)TeO₂-(10+x)WO₃-8BaO-2Na₂O-0.5Er₂O₃(x=0,5,10,15,20)玻璃,研究了WO₃对掺铒碲钨酸盐玻璃的光谱性质. 研究发现：随着WO₃含量的增加,Ω₄,Ω₆先增加后减小,受 关键词： 碲钨酸盐玻璃 3+光谱性质')" href="#">Er³⁺光谱性质 Judd-Offelt理论     

Unusual Ln substitutional defects: The local chemical environment of Eu and Er in nanocrystalline Nb2O5 by Ln-K edge EXAFS

The local chemical environment of the trivalent lanthanide cations in Nb₂O₅ nanopowders doped with 1 mol% of Eu³⁺ and Er³⁺, prepared via a Pechini approach, has been studied by means of EXAFS at the Ln-K edge. It can be demonstrated that the lanthanide ions enter the Nb₂O₅ structure as substitutional defects with respect to Nb, giving rise to a very large amount of disorder: both Eu³⁺ and Er³⁺ ions substitute Nb in the nine-fold coordinated site, with clustering of oxygen vacancies around the substitutional defects. Valence bond calculations have been used to validate the Ln-O distances obtained by the EXAFS fitting. The Er³⁺-doped nanocrystalline Nb₂O₅ sample shows efficient luminescence in the near infrared region around 1.5 μm. The emission and excitation spectra are affected by significant inhomogeneous broadening, in agreement with the presence of strong disorder around the dopant ions in nanosized Nb₂O₅.     

Upconversion emission in Er<Superscript>3+</Superscript>-doped lead niobium germanate thin-film glasses produced by pulsed laser deposition

Thin films of Er³⁺-doped lead–niobium germanate have been produced by pulsed laser deposition from Er³⁺-doped 25PbO₂–25Nb₂O₅–50GeO₂ (mol%) transparent glasses with an Er content in the range 0.5–3 wt%. The room-temperature infrared to visible upconversion properties of these thin films have been investigated under 800-nm laser excitation. An energy transfer upconversion mechanism has been identified to be responsible for the population of the ⁴S_3/2:²H_11/2 excited level, from which an intense green emission occurs. A rate equation analysis supports the proposed mechanism.     

掺铒高硅氧玻璃光谱性质的研究

应用Judd-Oflet理论计算了新型掺铒高硅氧玻璃中铒离子的强度参量Ω_t(t=2,4,6)，Ω₂=8.15×10^-20，Ω₄=1.43×10^-20，Ω₆=1.22×10^-20，相比于其他氧化物玻璃，表现出较大的Ω_2,6值，反映了铒离子周围的近邻结构不对称性和Er-O键的离子键成分较高.利用McCumber理论计算得到了能级^{关键词： 掺铒高硅氧玻璃 Judd-Ofelt理论 量子效率}     

Er3+/Ce3+共掺碲铋酸盐玻璃的制备及光谱特性提高研究

采用高温熔融退火法制备了系列 80TeO₂-10Bi₂O₃-10TiO₂-0.5Er₂O₃-xCe₂O₃ (x=0,0.25, 0.5,0.75,1.0 mol%)和(80-y) TeO₂-10Bi₂O₃-10TiO₂-yWO₃-0.5Er₂O₃-0.75Ce₂O₃ (y=3,6,9,12 mol%)的碲铋酸盐玻璃.测试了玻璃样品400-1700 nm范围内的吸收光谱, 975 nm抽运下的上转换发光谱和1.53 μm波段荧光谱, 以及808 nm激励下的Er³⁺离子荧光寿命和无掺杂玻璃样品的Raman光谱, 并结合Judd-Ofelt理论和McCumber理论计算了Er³⁺离子光谱参数.结果表明, 在掺Er³⁺碲铋酸盐玻璃中引入Ce³⁺离子进行Er³⁺/Ce³⁺共掺, 通过Er³⁺离子⁴I_11/2能级与Ce³⁺离子²F_5/2 能级间基于声子辅助的能量传递过程,可以有效抑制Er³⁺离子上转换发光并明显增强其 1.53 μm波段荧光;同时,在现有Er³⁺/Ce³⁺共掺玻璃组分基础上引入WO₃, 可进一步提高1.53 μm波段荧光并展宽其荧光发射谱. 研究结果对于获取优异光谱特性的宽带掺Er³⁺光纤放大器玻璃基质具有实际意义.     

可紫外激光刻写的掺铒铋硅酸盐玻璃光谱性质研究

报道了可紫外激光刻写的掺铒Na₂O-Bi₂O₃-SiO₂和Na₂O-B₂O₃-Bi₂O₃-SiO₂玻璃的光谱特性. 测量和计算了玻璃的光谱参数，分析、讨论了Bi₂O₃和B₂O₃含量变化对光谱参数的影响.实验表明基质玻璃中Bi₂O₃和B₂O₃含量改变可有效调节掺铒铋硅酸盐玻璃光谱参数.Bi₂O₃和B₂O₃含量增加，玻璃的光吸收和荧光性质改善，但Er³⁺离子的⁴I_13/2能级寿命降低.在B₂O₃含量为40%(Bi₂O₃/SiO₂＝0.67)时，Er³⁺离子峰值发射截面、⁴I_13/2能级的荧光寿命和荧光半高宽分别为8.49×10^－21cm²，0.52ms和78nm.结果表明掺铒铋硅酸盐玻璃是有前途的紫外光敏有源玻璃材料之一.     

Judd–Ofelt analysis and improvement of thermal and optical properties of tellurite glasses by adding P2O5

Er³⁺ and Er³⁺/Yb³⁺ co-doped tellurite glasses, suitable for developing optical fiber laser and amplifier, have been elaborated from the conventional melt-quenching method. Results of differential scanning calorimetry (DSC) measurements indicate a good thermal stability of tellurite glasses. The DSC measurements show an improvement of thermal stability of glass hosts after adding P₂O₅. Absorption spectrum from near infrared to visible was obtained and the Judd–Ofelt (J–O) intensity parameters (Ω₂, Ω₄, and Ω₆) were determined. Spontaneous emission probabilities of some relevant transitions, branching ratio, and radiative lifetimes of several excited states of Er³⁺ have been predicted using intensity J–O parameters. Absorption cross-section and calculated emission cross-section, using the McCumber method, for the ⁴I_13/2→⁴I_15/2 transition, were determined and compared for the doped and co-doped glasses. Energy transfer (ET) and effect of changing concentration of P₂O₅ and Yb³⁺ ions on spectroscopic properties were investigated. It was found that the addition of P₂O₅ can increase the symmetry of the Er³⁺ ion. As a consequence, PL lifetime becomes more longer.The spectroscopic properties and the efficient infrared luminescence indicate that Er³⁺ doped TeO₂–ZnO–Na₂O–Er₂O₃(TZNE) is a promising laser and amplifier materials and may be a potentially useful material for developing upconversion fiber optical devices.     

掺铒铋酸盐玻璃的光谱性质研究

研究了掺铒铋酸盐玻璃的吸收和荧光光谱性质,应用Judd-Ofelt理论计算了玻璃的三个强度参量Ω_t=(t=2,4,6),分别为Ω₂=3.71×10^-20cm²,Ω₄=1.86×10^-20cm²,Ω₆=1.28×10^-20cm²,计算了Er³⁺离子的自发跃迁几率、荧光分支比等光谱参量.经荧光谱测试发现掺Er³⁺铋酸盐玻璃的荧光半高宽可达70nm.应用McCumber理论计算1.53μm处的受激发射截面可达9×10^-21cm².对Er³⁺离子在不同基质玻璃中光谱特性的比较发现,Er³⁺在铋酸盐玻璃中具有相对较高的受激发射截面和宽的荧光半高宽.     

Tm3+/Yb3+共掺铋碲酸盐玻璃中的高效蓝色上转换荧光

制备了高折射率Tm³⁺/Yb³⁺共掺杂铋碲酸盐玻璃，利用棱镜耦合法测量出玻璃在632.8和1550nm波长处的折射率分别为2.0365和1.9795. 对玻璃的吸收、荧光和红外透过光谱展开了测试与分析，根据Judd-Ofelt理论对吸收光谱进行拟合，求得Tm³⁺的振子强度参数Ω_t(t=2，4，6)分别为3.90×10^-20, 2.03×10^-20和9.03×10^{-2 关键词： 3+}/Yb³⁺共掺')" href="#">Tm³⁺/Yb³⁺共掺 铋碲酸盐玻璃 光谱参数 上转换荧光     

Judd-Ofelt parameters of Er in transparent TeO2-based nanocrystallized glasses

Transparent Er³⁺-doped bulk nanocrystallized (size of nanocrystals: ∼40 nm) glasses of 15K₂O·15Nb₂O₅·70TeO₂·0.5Er₂O₃ and 10BaO·10Gd₂O₃·80TeO₂·0.5Er₂O₃ are prepared, and the Judd-Ofelt parameters, (t=2, 4, 6), of Er³⁺ are evaluated from optical absorption spectra. The change in the molar polarizability due to the nanocrystallization is small in both samples, but a clear decrease in the mean atomic volume due to the nanocrystallization, i.e. more close atom packing, is observed. In both systems, a large decrease is observed in the parameter due to the nanocrystallization, indicating that the degree of the site symmetry of Er³⁺ ions in nanocrystallized glasses is much higher than that in the precursor glasses. The decrease in the and parameters due to the crystallization is small, suggesting that the covalency of Er³⁺-O bonds in nanocrystals is not so different from that in the precursor glasses.     

Enhanced optical activation of Er in Er-doped Al2O3 powders by Y codoping in a sol-gel method

Enhanced photoluminescence (PL) mechanism of Er³⁺-doped Al₂O₃ powders by Y³⁺ codoping at wavelength 1.53 μm has been investigated through PL measurements of 0.1 mol% Er³⁺- and 0-20 mol% Y³⁺-codoped Al₂O₃ powders prepared at a sintering temperature of 900 °C in a non-aqueous sol-gel method. PL intensity and lifetime of Er³⁺-Y³⁺-codoped Al₂O₃ powders composed of γ-(Al,Er,Y)₂O₃ and θ-(Al,Er,Y)₂O₃ phases increased with increasing Y³⁺-codoping concentration. The 10-20 mol% Y³⁺ codoping in 0.1 mol% Er³⁺-doped Al₂O₃ powders intensified the PL intensity by about 20 times, with a PL lifetime prolonged from 3.5 to 5.8 ms. A maximal increase of the optical activity of Er³⁺ in 0.1 mol% Er³⁺-Y³⁺-codoped Al₂O₃ powders about one order was achieved by 10-20 mol% Y³⁺ codoping. It is found that the improved PL properties for Er³⁺-Y³⁺-codoped Al₂O₃ powders are mainly attributed to enhanced optical activation of Er³⁺ in the Al₂O₃ by Y³⁺ codoping, and to the slightly increased radiative quantum efficiency of Er³⁺ in the Al₂O₃.     

Optical properties of Er in MoO3-Bi2O3-TeO2 glasses

Erbium-doped MoO₃−Bi₂O₃−TeO₂ (MBT) glasses suitable for broadband optical amplifier applications have been fabricated and characterized optically. The maximum phonon band of undoped glasses is at 915 cm⁻¹, and the emission from the Er³⁺: ⁴I_13/2 → ⁴I_15/2 transition locates around 1.53 μm with a full width at half maximum (FWHM) of ∼80 nm. The lifetime and quantum efficiency of the ⁴I_13/2 level are 2.13 ms and ∼90%, respectively. Under the same measurement condition, the upconversion emission intensities at 550 nm in Er³⁺-doped MBT glasses is about 30 times weaker than that in Er³⁺-doped Na₂O−ZnO−TeO₂ (NZT) glasses.     

Energy transfer and infrared-to-visible upconversion luminescence of Er/Yb-codoped halide modified tellurite glasses

We report on the energy transfer and frequency upconversion spectroscopic properties of Er³⁺-doped and Er³⁺/Yb³⁺-codoped TeO₂-ZnO-Na₂O-PbCl₂ halide modified tellurite glasses upon excitation with 808 and 978 nm laser diode. Three intense emissions centered at around 529, 546 and 657 nm, alongwith a very weak blue emission at 410 nm have clearly been observed for the Er³⁺/Yb³⁺-codoped halide modified tellurite glasses upon excitation at 978 nm and the involved mechanisms are explained. The quadratic dependence of fluorescence on excitation laser power confirms the fact that the two-photon contribute to the infrared to green-red upconversion emissions. And the blue upconversion at 410 nm involved a sequential three-photon absorption process.