中文摘要：

设计并制备了一种组分为45Bi2O3—35GeO2—20PbO-0．02Tm2O3-xYb2O3（x=1．0，1．2，1．4，1．6和2．0 mol％）新型Tm^3＋／Yb^3＋共掺的铋锗铅玻璃材料，测量了玻璃的吸收光谱和上转换光谱，分析了玻璃中Tm^3＋的上转换发光机理。应用Judd—Ofelt理论计算了铋锗铅玻璃BGP1.0中Tm^3＋离子的三个强度参量亿（t=2，4，6）、振子强度、自发跃迁辐射几率和荧光分支比等光谱参数。通过975nm的激光二极管激发，在室温下同时观察到强烈的上转换蓝光（476nm）和微弱的红光（653nm），分别是由于Tm^3＋离子^G4→^3H6和^1G4→^3F4跃迁。同时研究了蓝光和红光上转换发光强度随泵浦激发功率的变化，其曲线斜率分别为2．87和2．41，表明蓝光和红光都是三光子吸收过程。研究结果显示，Tm^3＋／Yb^3＋共掺铋锗铅玻璃是一种上转换蓝光激光器的潜在基质材料。

英文摘要：

Novel Tm^3＋ and Yb^3＋ codoped bismuth-germanium-lead glass was fabricated and characterized; the glass sample components are 45Bi2O3-35GeO2-20PbO-0.02Tm2O3- xYb2O3 （x = 1.0, 1.2, 1.4, 1.6 and 2.0 mol%）. The absorption and upconversion spectra of Tm^3＋ and Yb^3＋ codoped in bismuth-germanium-lead glass were investigated, and upconversion mechanisms of Tm^3＋ in the glass were analyzed. The Judd-Ofelt intensity parameters Ωt （t = 2, 4, 6）, oscillator strengths, spontaneous transition probability and fluorescence branching ratio of each levels for Tm^3＋ were calculated by Judd-Ofelt theory. Intense blue and weak red emissions centered at 476 and 653 nm, correspongding to the transitions ^1G4→^3H6 and ^1G4 →^3F4, respectively, were simultaneously observed at room temperature under 975 nm diode laser.excitation. The upconversion emission intensity varies with the power of infrared excitation intensity. A plot of log /UP VS log IIR yields a straight line with slope 2.87 and 2.41, corresponding to the 476 and 653 nm emission bands, respectively, which indicates a three-photon process for the blue and red emissions. The results suggest that Tm^3＋ and Yb^3＋ codoped bismuth-germanium-lead glass may be a potential host material for upconversion blue lasers.