Tm3+掺杂锗铌酸盐玻璃及其红外光谱特性

用高温熔融法制备了相同质量百分比浓度4%Tm₂O₃掺杂浓度下(90-x)GeO₂-xNb₂O₅-10Na₂O(其中数字为摩尔百分比x=1,2,4,6,8)以及Tm₂O₃掺杂浓度分别为质量百分比1%,2%,3%,4%下86GeO₂-4Nb₂O₅-10Na₂O(其中数字为摩尔分数)系列玻璃.研究了Nb₂O₅组分对玻璃热稳定性,荧光强度和J-O参数的影响.应用Judd-Ofelt理论,计算了Tm³⁺离子在Nb₂O₅浓度不同时的J-O强度参数(Ω₂,Ω₄,Ω₆)及Tm³⁺离子各激发态能级的自发跃迁概率、荧光分支比以及辐射寿命等光谱参量.根据McCumber理论,计算了Tm³⁺离子能级³F₄→³H₆(1.8 μm)跃迁的吸收截面和受激发射截面.从获得的吸收截面、发射截面与离子掺杂浓度计算了1.8 μm荧光波段的增益截面曲线.在808 nm波长光的激发下,研究了Tm³⁺掺杂玻璃在1.47与1.8 μm附近的荧光特性.发现当Tm₂O₃掺杂浓度为质量百分比3%时,在1.8 μm处的荧光强度达最大,然后随着掺杂浓度的增大,其荧光强度反而降低;当Nb₂O₅摩尔分数含量大约在2%时,Tm³⁺在1.8 μm处的荧光强度最强.并讨论了Nb₂O₅组分变化对玻璃结构与光谱特性的影响情况.关键词：3+掺杂锗铌酸盐玻璃')" href="#">Tm³⁺掺杂锗铌酸盐玻璃红外光谱性质交叉弛豫2O₅')" href="#">Nb₂O₅

Germanium-niobate glasses doped with Tm3+ and their Infrared spectral properties

Glasses with the compositions of (90-x)GeO₂-xNb₂O₅-10Na₂O(x=1,2,4,6,8 molar ratio)doped with Tm₂O₃ at the same concentration (4wt%) and 86GeO₂-4Nb₂O₅-10Na₂O dore at different concentrations were fabricated respectively by conventional melting method.The effects of Nb₂O₅ content on glass stability,fluorescence strength and J-O strength parameters were studied.According to the Judd-Ofelt theory,the J-O strength parameters (Ω₂, Ω₄, Ω₆) of Tm³⁺ in different Nb₂O₅ concentration were calculated,with which the radiative transition probabilities,branching ratios and radiative lifetime were obtained.Meanwhile,according to the McCumber theory,the absorption and emission cross-sections corresponding to the ³F₄→³H₆ transitions of Tm³⁺ at 1.8 μm were obtained.The gain cross section was calculated by using the emission cross-section,absorbtion cross section and Tm³⁺ concentration.The fluorescence features (under 808 nm LD excitation) at ～1.47 and ～1.8 μm of Tm³⁺-doped glasses of different concentrations were studied.The fluorescence intensity at ～1.8 μm reached to the maximum when the Tm₂O₃-doping concentration was about 3wt%,and then decreased as the doping concentration increased further.The fluorescence intensity at ～1.8 μm reached to the maximum when the Nb₂O₅ content in glass composition was about 2 mol%.The effects of Nb₂O₅ content on the glass structure and the spectra properties were also discussed.