制备了适用于钾钠离子交换波导的钬镱离子掺杂锗酸盐玻璃, 采用荧光光谱绝对测试系统在975nm激光泵浦下对玻璃的上转换发光性能进行表征, 解析出样品的绝对光谱功率分布, 并计算了光量子数分布和荧光量子产率等绝对荧光参量.测试与计算结果表明, 当Ho3+/Yb3+掺杂的锗酸盐玻璃在370℃的KNO3熔盐中热离子交换4 h时, K+-Na+离子交换有效扩散系数为0.068 μm2/min.锗酸盐玻璃样品中, Ho3+主要发出548 nm绿光和660 nm红光, 其中红色上转换荧光为支配性发射.当激光激发功率密度为1 227 W/cm2时, 660 nm红光绝对光谱功率和净发射光量子数分别为28.03 μW和9.26×1013 cps.此时, 548 nm绿光和660 nm红光发射的荧光量子产率分别为0.17×10－5和2.41×10－5, 可见区总荧光量子产率达2.61×10－5.净发射光子数与激发功率密度的双对数曲线斜率表明Ho3+/Yb3+掺杂锗酸盐玻璃的红色和绿色上转换发射均属双光子激发过程.基于波导适用型锗酸盐玻璃实施的钬离子上转换荧光发射的绝对化表征, 为稀土光电功能材料的进一步研发提供了可依赖的数据参考.

Ho3+/Yb3+ doped germanate glasses adapting for K+-Na+ ion-exchanged waveguide were fabricated. Upconversion fluorescence has been measured by absolute spectral measurement system under 975 nm diode laser excitation. Net absorption and emission photon distributions and quantum yields were derived from absolute spectral power distributions. Experimental and calculation results revealed that the effective diffusion coefficient of K+-Na+ thermal ion-exchange is 0.068 μm2/min, when Ho3+/Yb3+ doped germanate glasses are immersed in KNO3 molten salt at 370℃ for 4 hours. Ho3+ in germanate glasses emits 548 nm green and 660 nm red fluorescence, and the red one plays dominant role. The absolute spectral powers and the net emission photon numbers of the red upconversion emission are 28.03 μW and 9.26×1013 cps, when pump power density is adjusted to 1 227 W/cm2. The fluorescence quantum yields of 548 nm green and 660 nm red emissions are 0.17×10－5 and 2.41×10－5, respectively, and the total quantum yield in the visible region can reach to be 2.61×10－5 simultaneously. The slope of logarithmic curve of net emission photon number versus excitation power density indicate that the red and green upconversion emissions in Ho3+/Yb3+ doped germanate glasses are both due to two-photon excitation processes. Absolute characterization for the upconversion fluorescence from Ho3+ in waveguide-typed germanate glasses have been achieved, which provides reliable reference in developing rare earth optoelectronic functional materials.