Tm^(3+)掺杂锗铌酸盐玻璃及其红外光谱特性  

Germanium-niobate glasses doped with Tm^(3+) and their Infrared spectral properties

作　　者：王勇超[1] 夏海平[1] 章践立[1] 张勤远[2] 

机构地区：[1]宁波大学光电子功能材料重点实验室,宁波315211 [2]华南理工大学光通信材料研究所特种功能材料教育部重点实验室,广州510640

出　　处：《物理学报》2010年第8期5808-5816,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60777030);宁波市重点实验室开放基金(批准号:2007A22010);宁波大学王宽诚幸福基金资助的课题~~

摘　　要：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(1.8μm)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1.8μm荧光波段的增益截面曲线.在808nm波长光的激发下,研究了Tm3+掺杂玻璃在1.47与1.8μm附近的荧光特性.发现当Tm2O3掺杂浓度为质量百分比3%时,在1.8μm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1.8μm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.Glasses with the compositions of （90 - x）GeO2 -xNb2 O5 -10Na2 O（x = 1,2,4,6,8 molar ratio）doped with Tm2 O3 at the same concentration （4wt% ） and 86GeO2 -4Nb2 O5 -10Na2 O dore at different concentrations were fabricated respectively by conventional melting method. The effects of Nb2 O5 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 Nb2 O5 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 3 F4 → 3 H6 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 Tm2 O3 -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 Nb2 O5 content in glass composition was about 2 mol% . The effects of Nb2 O5 content on the glass structure and the spectra properties were also discussed.

关 键 词：Tm^3+掺杂锗铌酸盐玻璃 红外光谱性质 交叉弛豫 NB2O5 

分 类 号：TQ171.1[化学工程—玻璃工业]