Spectroscopic properties of Nd—doped phosphate glass with a high emission cross section

Neodymium doped phosphate glasses have been prepared by the semi-continuous melting technique. Their absorption and emission spectra have been recorded at room temperature. The Judd－Ofelt theory has been applied to evaluate the stimulated emission cross sections of ⁴F_3/2→⁴I_11/2 transition for Nd³⁺. The higher stimulated emission cross section, 4.0×10^-20cm², is obtained. The fluorescence decays of the ⁴F_3/2→⁴I_11/2 transition of Nd³⁺ are measured for the samples doped (0.7－10) wt% of Nd₂O₃ at room temperature. The concentration quenching of Nd-doped phosphate glass is mainly attributed to cross-relaxation and energy migration. The site-dependent properties of fluorescence spectra and the fluorescence lifetime of the Nd³⁺-doped phosphate glass (with 2.2wt%Nd₂O₃) are studied using laser-induced fluorescence line narrowing techniques, and the site-to-site variations of optical properties are observed at low temperature.     

Optical parameters of Nd3＋：Er3＋：yb3＋ co-doped borosilicate glasses and their energy transfers at high temperature

This paper reports that a series of Nd³⁺:Er³⁺:Yb³⁺ co-doped borosilicate glasses have been prepared and their absorption spectra measured. The J--O intensity parameters Ω_k (k=2, 4, 6), spontaneous radiative lifetime τ_rad, spontaneous transition probability A, fluorescence branching ratio β and oscillator strength f_ed of the Nd³⁺ ions at room temperature are calculated based on Judd--Ofelt (J--O) theory. The temperature dependence of the up-conversion photoluminescence characteristics in a Nd³⁺:Er³⁺:Yb³⁺ co-doped sample is studied under a 978 nm semiconductor laser excitation, and the energy transfer mechanisms among Yb³⁺, Er³⁺ and Nd³⁺ ions are analysed. The results show that the J--O intensity parameters Ω₂ increase when the Nd³⁺ concentration of the Nd³⁺:Er³⁺:Yb³⁺ co-doped borosilicate glasses increases. The possibility of spontaneous transition is small and lifetimes are long at levels of ⁴F_5/2 and ⁴F_3/2. The intensity of Nd³⁺ emissions at 595, 691, 753, 813 and 887 nm are markedly enhanced when the sample temperature exceeds 400 K. The reasons being the cooperation of the secondary sensitization from Er³⁺ to Nd³⁺ and the contribution of a multi-phonon.     

Spectroscopic properties in Er Er3+/Yb3+Co-doped fluorophosphate glass

Using the technique of high-temperature melting, a new Er³⁺/Yb³⁺ co-doped fluorophosphate glass was prepared. The absorption and fluorescence spectra were investigated in depth. The effect of Er³⁺ and Yb³⁺ concentration on the spectroscopic properties of the glass sample was also discussed. According to the Judd-Ofelt theory, the oscillator strength was computed. The lifetime of ⁴I_13/2 level (τ_m) of Er³⁺ ions was 8.23 ms, and the full width at half maximum of the dominating emission peak was 68 nm at 1.53 τ_m. The large stimulated emission cross section of the Er³⁺ was calculated by the McCumber theory. The spectroscopic properties of Er³⁺ ion were compared with those in different glasses. The full width at half maximum and σ_e are larger than those of other glass hosts, indicating this studied glass may be a potentially useful candidate for high-gain erbium-doped fiber amplifier.     

Structures and luminescence properties of Yb3＋ in the double perovskites Ba2YB＇O6 （B＇=Ta5＋, Nb5＋） phosphors

The Yb³⁺ doped Ba₂YB'O₆ (B'=Ta⁵⁺, Nb⁵⁺) were prepared by high temperature solid-state reaction method, their structures were determined by x-ray diffraction and refined by Rietveld method. The diffuse reflection absorption, excitation and emission spectra of Yb³⁺:Ba₂YB'O₆ (B'=,Ta⁵⁺, Nb⁵⁺) were measured at room temperature. Under the excitation of ultraviolet light, these phosphors exhibit broad charge transfer band emissions of TaO₆ or NbO₆ centre with large Stokes shift. The Yb³⁺ doped into these hosts are situated at Y³⁺ sites of cubic symmetry (O_h). The experimental energy levels of Yb³⁺ in Ba₂YTaO₆ and Ba₂YNbO₆ were determined by photoluminescence and diffuse reflection absorption spectra. Their wavefunctions and theoretical energy levels were obtained by diagonalising the Hamiltonian matrix. The experimental energy levels were fitted by Levenberg--Marquardt iteration algorithm to determine crystal field parameters. Then, the magnetic-pole transition line strengths of Yb³⁺:Ba₂YB'O₆(B'=Ta⁵⁺, Nb⁵⁺) from (²F_5/2)Γ₈^- to the low-energy states were calculated.     

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.     

Er3+单掺及Er3+/Yb3+共掺SiO2-Al2O3-La2O3玻璃光谱性质研究

研究了单掺Er³⁺及Er³⁺/Yb³⁺共掺SiO₂-Al₂O₃-La₂O₃玻璃的光谱性质随稀土离子浓度变化规律,应用McCumber理论计算了玻璃在1.53 μm的发射截面及积分吸收截面.结果表明:在Er³⁺离子掺杂浓度相同时,玻璃在980 nm吸收截面与Yb³⁺掺杂浓度成反比;当样品中Yb³⁺离子掺杂浓度为3.94×10²⁰ cm^-3时,玻璃在1.53 μm的吸收截面和发射截面最大,在1.40～1.60 μm积分吸收截面也最大;Er³⁺/Yb³⁺共掺SiO₂-Al₂O₃-La₂O₃玻璃在1.53 μm的荧光半高宽随Er³⁺掺杂浓度升高而增加,当Er³⁺离子掺杂浓度为2.41×10²⁰ cm^-3时,玻璃的荧光半高宽(FWHM)达到52.5 nm.     

Nonlinearity of refractive index in glasses based on heavy metal oxides with different lead and tellurium contents

We have studied the nonlinearity of the refractive index at a wavelength of 1.08 μm for optical lead silicate and lead phosphate tellurite glasses of different compositions. We have shown that the nonlinear refractive index n₂ increases as the lead content increases in lead silicate glasses and as the tellurium content increases in lead phosphate tellurite glasses, where the latter are typically have higher values of n₂, as high as 24·10⁻¹³ cgs units (47·10⁻¹⁶ cm²/W), and lower Rayleigh losses. We have established a correlation between the nonlinear refractive index and the microstructure of the studied glasses. The highly nonlinear glasses are distinguished by extensive fluctuations in the heavy metal oxide concentration which are “frozen” during cooling of the glass melt. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 6, pp. 780–784, November–December, 2007.     

Er3+/Yb3+共掺碲钨酸盐玻璃的光谱性质和热稳定性的研究

制备了Er³⁺和Yb³⁺共掺的碲钨酸盐玻璃样品65TeO₂-25 WO₃-10R_mO_n(R_mO_n=PbO,BaO),(65+x)TeO₂-(25-x)WO ₃-10La₂O₃ (x=0,5,10), (60+x)TeO₂-(30 -x)WO₃-10Bi₂O₃ (x=0,5,10).测试了玻璃样品的吸收光谱、荧光光谱、能级寿命及热稳定性能.结果表明除含Bi ₂O₃的碲钨酸盐玻璃外，其余玻璃样品均没出现析晶开始温度(T_x)，说明碲钨酸盐 是一种适合于光纤拉制的玻璃基质材料.应用Judd-Ofelt理论计算了强度参数Ω_t(t=2, 4,6)，研究表明Ω₂在碲钨酸盐玻璃中主要受到Er-O键的共价性的影响，而Er^{3 +} 离子周围配位场的非对称性影响可以忽略.测得了Er³⁺在15 μm发射谱的荧光 半高宽 (FWHM=71—77nm)和Er³⁺的⁴I_13/2能级寿命 (τ^m=3—34 ms).应用McCumber理论计算了Er³⁺在15 μm处的受激发射截面(σ^peak=068—103×10^-20 cm²).比较了Er³⁺在不同玻璃基质里 的15 μm荧光带宽和发射截面，研究结果表明碲钨酸盐玻璃是一种制备宽带光纤放大器的理想基质材料.     

CALCULATION OF THE FINE STRUCTURE OF OXYGEN-LIKE IONS USING THE POLARIZATION POTENTIAL FUNCTION

We have calculated the forbidden transition energies and magnetic dipole transition probabilities of 2s²2p⁴(³P₁－³P₂) and 2s²2p⁴ (³P₀－³P₁) of oxygen-like isoelectronic sequences (Z=10－32) by a method of polarization potential correction. The transition energies show good agreement with experiment and are much better than the calculations in the literature. These results also illustrate that it is feasible to use the dipole expansion of the polarization potential to deal with some dynamic and non-dynamic effects in the central field approach. The relation of polarizability and cut-off radius with atomic number is discussed. We also give the fitted formula between the polarizability α₁ and atomic number Z as α₁=0.73429-9.56644×10^-4Z+7.43016×10^-5Z^{2-2.53298×10-6Z3+2.08306×10-8Z4.}     

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     

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+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     

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.     

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.     

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.