970 nm抽运下Tm3+/Yb3+共掺氧氟玻璃的频率上转换发光

稀土离子掺杂的氧氟玻璃是一种新型上转换发光材料。制备了Tm^3／Yb^3＋单掺、共掺的摩尔分数为n（SiO2）-0．30，n（PbF2）-0．50，n=（Al2O3）=0．15，n（AlF3）=（0．049-x），n（TmF3）=y，n（YbF3）=x（x=0，0．001，0．010，0．015，0．020，y=0，0．001）系统氧氟玻璃，研究了其上转换发光特性、分析了其上转换发光机理。研究发现，在970nm抽运光源激发下，Tm^3＋单掺时没有可见光上转换发射；而加入Yb^3＋后产生了强的蓝光（452nm，476nm）、红光（647nm）及近红外光（791nm）发射，分别对应如下辐射跃迁：^1D2→^3F4、^1G4→^3H6、^1G4→^3F4和^3H4→^3H6；且随着Yb^3＋离子浓度的增加上转换发光增强。在970nm光源抽运下用Yb^3＋敏化Tm^3＋可以显著提高其上转换发光强度，且随着Yb^3＋离子浓度的增加，增强了对抽运光源的吸收并提高了Yb^3＋到T^3＋”的能量转移几率，从而增强了上转换发光强度。

Upconversion Luminescence of Tm3+/Yb3+ Codoped Oxyfluoride Glasses Ppumped at 970 nm

A new oxyfluoride glass system was developed with molar fractions of n(SiO2)=0.30,n(PbF2)=0.50,n=(Al2O3)=0.15,n(AlF3)=(0.049-x),n(TmF3)=y,n(YbF3)=x(x=0,0.001,0.010,0.015,0.020,y=0,0.001) and its upconversion emission properties were investigated. Furthermore the upconversion mechanism was discussed. The experimental results showed that there was not upconversion emission for Tm3+ singly doped glasses under 970 nm excitation. While strong blue (452 nm, 476 nm), red (647 nm) and near infrared (971 nm) emissions were found in Tm3+/Yb3+ codoped glasses, which responded to the following radiative transition: 1D2→3F4, 1G4→3H6, 1G4→3F4 and 3H4→3H6. Moreover, the intensity of upconversion luminescence was strongly dependent on the concentration of Yb3+. It was indicated that under 970 nm excitation the upconversion luminescence intensity of Tm3+ increased with Yb3+ sensitizing. With Yb3+ concentration increasing, absorption of pump source and energy transfer between Tm3+ and Yb3+ were both enhanced, and as a result the upconversion luminescence intensity was increased.