Er3+/Yb3+共掺TeO2-WO3-Bi2O3玻璃的光谱性质和上转换发光

本文制备了Er³⁺/Yb³⁺共掺TeO₂-WO₃-Bi₂O₃(TWB)玻璃. 测试和分析了样品的吸收光谱、荧光光谱及上转换发光. 用Judd-Oflet(J-O)理论计算了Er³⁺在玻璃样品中的光谱强度参数,随着Bi₂O₃含量的增加,Ω₂增加,Ω₄ 关键词： 碲酸盐玻璃 光谱性质 上转换     

掺铒碲-钨-钠玻璃基质的光谱性质研究

制备了用于离子交换法制备光波导器件的掺铒碲-钨-钠玻璃基质。应用扎得-奥菲而特(Judd—Ofelt)理论计算了玻璃样品的三个强度参量,由强度参量计算了Er^3 离子的自发跃迁几率、荧光分支比等光谱参量;应用麦克库玻(McCumber)理论,计算了Er^3 离子在1．5μm的受激发射截面,荧光测试发现Er^3 离子的荧光半峰全宽可达65nm。比较了Er^3 离子在不同玻璃基质中的光谱特性。结果表明,Er^3 离子在碲-钨-钠玻璃中具有较高的受激发射截面和较宽的荧光半峰全宽,可以用于宽带光波导器件的制备。     

Yb3+/Er3+共掺杂TeO2-WO3-ZnO玻璃的光谱性质

制备了Yb³⁺/Er³⁺共掺杂的TeO₂-WO₃-ZnO玻璃,测量了Er³⁺在玻璃中的吸收光谱和970nmLD激发下的荧光光谱、荧光寿命和上转换光谱.计算了Yb³⁺/Er³⁺间的能量传递效率和Er³⁺离子1.5μm波段的吸收截面、发射截面,并研究了其荧光强度和上转换发光与Yb³⁺掺杂浓度间的关系.结果表明,Yb³⁺共掺杂可明显提高Er³⁺离子1.5μm发射的荧光强度,实验所得Yb³⁺离子的最佳掺杂浓度为Er³⁺离子浓度的3倍,在7.28×1020ions/cm³左右.Er³⁺离子1.5μm发射的荧光半峰全宽为67～72nm;上转换红、绿光均为双光子过程,随Yb³⁺掺杂浓度的增加,上转换红、绿光强度均增强.     

Ce3+对Er3+/Yb3+共掺TeO2-WO3-ZnO玻璃发光性能的影响

在Er3+/Yb3+共掺TeO2-WO3-ZnO玻璃中引入Ce3+,研究了Ce3+对Er3+1.5μm发射性能及其上转换发光性能的影响.结果表明,随Ce3+浓度的增加Er3+1.5μm波段的荧光强度先增强后降低,优化的Ce3+掺杂浓度在2.07×1020/cm3左右;1.5μm波段的荧光寿命则随Ce3+浓度的增加有轻微降低,从3.4ms降到3.0ms,但Ce3+浓度的增加对1.5μm波段的荧光半高宽基本无影响;Er3+/Ce3+间的交叉弛豫Er3+(4I11/2+Ce3+(2F5/2→Er3+(4I13/2+Ce3+(2F7/2使玻璃的上转换发光强度大大降低,但在过高的Ce3+浓度下,Er3+/Ce3+间的另一交叉弛豫Er3+(4I13/2+Ge3+(2F5/2→Er3+(4I15/2+Ce3+(2F7/2则使Er3+4I13/2能级粒子数减少,导致1.5μm波段荧光强度和荧光寿命降低.     

Electrical properties of films of TeO2-Sb2O3 glasses

It is shown that TeO₂-Sb₂O₃ films may be producted by vacuum evaporation. Stable properties are produced if the films are given an additional treatment in an oxidizing medium. Results are given for , tan , and as functions of temperature and other parameters.     

Spectroscopic properties of Er3+-doped AlF3-La2O3-Al2O3-SiO2 glasses

Er3+-doped fluoride lanthanum aluminosilicate glasses with compositions of (65- x/2)SiO2 · (25 -and their glass transition temperatures and spectroscopic properties were investigated. The Ω2, Ω4, and Ω6 intensity parameters of glasses were calculated by Judd-Ofelt theory from absorption curves. It was found that glasses transition temperature and melting temperature decreased with the increase of fluoride content in glass, Ω2 decreased gradually with the increase of AlF3 content, but both Ω4 and Ω6 did not increase until AlF3 content increased to 30 mol%. The quantum efficiency of 4I13/2 to 4I15/2 transition of Er3+ ions increases with the increase of AlF3 content in glass. Fluorescent lifetime is longer in glass containing more AlFa content.     

Dipole correlations in TeO2-WO3 glass

Capacitance and thermally stimulated depolarization current measurements on TeO₂·0.23WO₃ glass from 4.2–300 K reveal structure at temperatures where phase transitions are observed in crystalline WO₃. These results indicate that the local WO₆-octahedra determine the dielectric properties of this glass and that dipole-dipole correlations contribute to the ferroelectric-like character of this amorphous system.     

Er3+/Yb3+共掺碲硼硅酸盐玻璃的光谱性质和热稳定性研究

制备了系列Er3+/Yb3+共掺碲硼硅酸盐玻璃样品(85-x)TeO2-15B2O3-xSiO2(TBS X=0,5,10,15,20 mol%).测试和分析了样品的吸收光谱、荧光光谱、能级寿命、红外透射光谱及差热特性.并通过对Er3+离子4I13/2→4I15/2跃迁发射谱线的高斯拟合,设计了一个简单的四能级结构估算了Er3+离子4I13/2和4I15/2能级在碲硼硅酸盐中的Stark分裂情况.研究表明SiO2的引入能有效地改善玻璃的热稳定性和光谱性能,玻璃析晶温度Tx与玻璃转变温度Tg之差(△T=Tx-Tg)可达178℃,说明碲硼硅酸盐是一种适合于光纤拉制的玻璃基质材料.比较了不同基质玻璃中Er3+离子的荧光半高宽和受激发射截面,结果表明TBS玻璃系统具有较好的带宽性能,是一种优良的宽带光纤放大器候选基质材料.     

Gamma-ray induced reduction of W6+ into W5+ in the Na2O -WO3 glasses

The ESR spectra of the 38Na₂O · 62WO₃ glasses irradiated with the⁶⁰Co -rays of 10⁵–10⁶ Gy comprised a broad singlet peak (g=1.65, H _pp=28.6 mT), a narrow singlet (g=2.00₁, H _pp=1.36 mT), and a narrow doublet (g=2.00₁, H _pp=0.72 mT,A=4.96 mT). The broad singlet and the two narrow peaks were respectively ascribed to the W⁵⁺ and the W-OHC (oxygen hole center) produced by the -ray irradiation. The _D (360 K) and _E (180 K), obtained from the low-temperature¹¹⁹Sn-Mössbauer measurement of 38Na₂O · 61WO₃·SnO₂ glass, indicated that octahedral Sn⁴⁺ substituted for octahedral W⁶⁺ and played a role of network former (NWF). A gradual increase in the isomer shift () from –0.02 to 0.09 mm s^–1 was observed with an increasing -ray dose, due to the charge transfer from oxygen to the Sn⁴⁺.     

pr3+掺杂透明氟氧化物玻璃陶瓷的光谱特性

根据pr3+掺杂透明氟氧化物玻璃陶瓷(Pr(0.2)∶FOV)样品在室温下的吸收光谱,分别采用了标准和修正的Judd-Ofelt理论拟合出J-O强度三参量Mn.结果表明,此修正的J-O理论应用到Pr(0.2):FOV材料的跃迁强度计算中是合理的和必要的.并由此修正理论计算了各个激发态之间跃迁的振子强度、自发辐射速率、荧...     

Spectroscopic properties of Pr 3+ in anisotropic PbWO4 crystal

The polarized absorption spectra, polarized fluorescence spectra, and fluorescence decay curves of Pr³⁺ ions in anisotropic PbWO₄ single crystal, which was grown by the modified Bridgman method, were measured at room temperature. The standard and modified Judd–Ofelt theories, extended to anisotropic crystal, have been applied to analyze the spectra. The spectroscopic parameters, including the Judd–Ofelt intensity parameters _t(t=2,4,6), spontaneous emission probabilities, fluorescence branching ratios, radiative lifetimes, stimulated emission cross sections, and fluorescence quantum efficiencies, were estimated. The good spectroscopic properties show the possible application of the Pr³⁺-doped PbWO₄ crystal as solid-state and self-stimulated Raman laser materials. PACS 78.20.-e; 42.70.Hj     

Spectroscopic properties of Sm3+ ions in lead fluorophosphate glasses

The Sm³⁺-doped lead fluorophosphate glasses of composition 44P₂O₅–17K₂O–9Al₂O₃–(24?x)PbF₂–6Na₂O–xSm₂O₃, where x=0.01, 0.05, 0.1, 0.5, 1.0 and 2.0 mol%, have been prepared by conventional melt quenching technique and are characterized through differential thermal analysis, Raman, absorption and emission spectra and decay rate measurements. Free-ion Hamiltonian model for energy level analysis and Judd–Ofelt theory for spectral intensities have been used to analyze the spectroscopic properties of Sm³⁺ ions in lead fluorophosphate glasses. The decay rates for the ⁴G_5/2 level of Sm³⁺ ions have been measured and are found to be single exponential at lower concentration (≤0.1 mol% Sm₂O₃) and turn into non-exponential at higher concentrations (≥0.5 mol% Sm₂O₃) due to energy transfer through cross-relaxation. The experimental lifetimes for ⁴G_5/2 level of Sm³⁺ ions are found to decrease from 2.54 to 0.92 ms when the concentration increased from 0.01 to 2.0 mol% Sm₂O₃ due to energy transfer. In order to know the nature of the energy transfer mechanism, the non-exponential decay rates are well fitted to Inokuti–Hirayama model for S=6, which indicates that the energy transfer process is of dipole–dipole type.     

Er3+/Yb3+共掺TeO2-Li2O-B2O3-GeO2玻璃系统的光谱性质和热稳定性研究

制备了Er3+/Yb3+共掺的70TeO2-5Li2O-(25-x)B2O3-xGeO2(x=0,5,10,15,20 mol%)系列玻璃,研究了玻璃的热稳定性能,测试了玻璃的吸收光谱、荧光光谱以及Er3+离子4I13/2能级荧光寿命,并根据McCumber理论计算了Er3+离子4I13/2→4I15/2跃迁的受激发射截面.结果表明:随着GeO2含量的增加,玻璃的热稳定性逐渐提高,荧光谱线半高宽(FWHM)保持在70 nm左右,而荧光强度和Er3+离子4I13/2能级荧光寿命逐渐提高,研究表明这种玻璃系统是一种具有应用潜能的宽带光纤放大器用的基质材料.     

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σe,分析了Er3+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.     

Er3+及Er3+/Yb3+共掺铋酸盐玻璃光谱性质研究

制备了Ed3+及Ed3+/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,Ω6=(1.29-0.80)×10-20cm2.比较了Er3+及Er3+/Yb3+共掺铋酸盐玻璃在980 nm附近的吸收截面和1.5μm的荧光发射光谱强度,Er3+/Yba+共掺铋酸盐玻璃的荧光光谱半高宽达到91 nm,比Er3+单掺铋酸盐玻璃大15 nm.用McCumber理论计算了Ed3+在1.5 μm的受激发射截面σe=1.00×10-20cm2.比较了Ed3+在不同基质中的光谱特性,结果表明铋酸盐玻璃更适合作为掺铒光纤放大器的基质材料.     

Tm3+/Ho3+共掺镓铋酸盐玻璃1.47 μm发光特性和能量传递的研究

报道了Tm3+/Ho3+共掺的镓铋酸盐玻璃14Ga2O3-25Bi2O3-20GeO2-31PbO-10PbF2玻璃1.47μm(S波段)发光和能量传递特征,应用Judd-Ofelt理论计算了玻璃的强度参数Ω,(t=2,4,6),自发辐射概率 A、荧光分支比β,荧光辐射寿命τ等各项光谱参数以及有效荧光线宽△λeff和峰值发射截面σpeake.通过测量荧光光谱和荧光寿命研究了Ho3+离子掺杂浓度对Tm3+离子1.47μm波段发光性能的影响,分析了Tm3+和Ho3+之间的能量传递过程.结果表明一定浓度内Ho3+的共掺迅速降低了Tm3+:3 F4能级的粒子数,而对3H4能级粒子数影响不大,从而降低了3F4和3H4能级间布居数反转的难度,极大地提高了1.47 μm发光效率.研究表明镓铋酸盐玻璃是适用于S波段光纤放大器的一种潜在基质材料,而掺杂一定浓度的Ho3+离子有利于提高Tm3+离子在1.47μm波段的发光效率.     

Spectroscopic properties of Tm3+ in fluorophosphate glasses

The optical properties of Tm³⁺ in a fluorophosphate glass are reported. Oscillator strengths and Ω_λ parameters for Tm³⁺ were calculated. Energy transfer between Ce³⁺ → Tm³⁺, Tm³⁺ → Eu³⁺ and Tm³⁺ → Tb³⁺ were measured at room temperature and interpreted using the Yokota and Tanimoto scheme. Fluorescence decay results seem to support the hypothesis of a diffusion-limited relaxation. The effects of Tb³⁺ and especially Ce³⁺ on the fluorescence of Tm³⁺ ion point out the interest of these dopants for obtaining a better emission of Tm³⁺ at 450 nm.     

Nonlinear Optics properties of Er2O3- doped 75Nb2O5-20TeO2-5ZnO glasses

We have performed time-resolved degenerate four-wave mixing(DFWM)experiments in 75Nb2O5-20TeO2-5ZnO glasses doped by Er2O3 at different excitation intensities and lattice temperatures.DFWM signalexhibits three peaks at high excitation intensities,where a main peak appears at zero time delay and tworather weak side peaks locate symmetrically at the negative and positive time delay,respectively.Themain peak is attributed to local-field effect and two side peaks are attributed to Coulomb interaction(CI).     

具有高机械强度的掺Er3+∶TeO2-Nb2O5玻璃的光谱性质研究

熔制了掺铒碲铌玻璃样品(100-X)TeO2-XNb2O5(X=5,10,15,20 mol%),测试了其密度、折射率、转变温度、析晶温度、维氏机械强度、吸收光谱、荧光光谱、荧光寿命等参量.利用Judd-Ofelt和McCumber理论分别计算了铒离子强度参量Ωt (t=2, 4, 6)和受激发射截面σemi的大小,研究了掺铒碲铌玻璃样品光谱参量对Nb2O5成分的依赖性,并与典型的碲锌钠玻璃(75TeO2-20ZnO-5Na2O)在热学、机械强度、光谱性质和放大品行四个方面进行了比较.     

Spectroscopic and lasing properties of Er3+:Yb3+-doped fluoride phosphate glasses

Er³⁺ emission and lasing properties at 1.5 μm were studied in fluoride phosphate glasses (FP20) with different doping concentrations as well as in a commercial phosphate glass (Kigre QX). Emission decay behaviour at 1 μm and 1.5 μm was examined with respect to energy transfer between ytterbium and erbium. Emission cross-sections were determined using the reciprocity and Füchtbauer–Ladenburg methods. Gain spectra were calculated for the glasses and related to differences in the tuning curves and lasing properties. The temperature rise due to the quantum defect was determined via the ratios of green upconversion luminescence for different pump powers. The results from the laser and tuning experiments indicate that the FP20 glass offers good possibilities in broadband amplification and the generation of ultrashort pulses. Received: 24 August 2000 / Revised version: 27 October 2000 / Published online: 7 February 2001