以柠檬酸为燃烧剂, 掺杂摩尔分数为2%的Ho3+, 采用低温燃烧法制备Ho∶YbGG多晶粉体。 通过对样品的X射线衍射和扫描电镜分析, 确定最佳煅烧温度为900 ℃。样品的吸收光谱在536 nm和645 nm处出现较强吸收峰, 分别对应Ho3+的5I8→5F4(5S2)和5I8→5F5能级跃迁; 在940 nm和982 nm处出现强吸收谱带, 对应于Yb3+的2F7/2→2F5/2能级跃迁。样品的荧光光谱在1 989 nm处有强发射谱带, 对应于Ho3+的5I7→5I8能级跃迁。样品可以发出较强的上转换绿光和红光, 分别对应于Ho3+的5F4(5S2)→5I8和5F5→5I8能级跃迁。对相应的上转换机制也进行了分析。

Holmium doped ytterbium gallium garnet (Ho∶YbGG) polycrystal powder was synthesized by low temperature combustion method using citric acid as combustion agent. The mole fraction of Ho3+ was 2%. The Ho∶YbGG polycrystal powder was determined by X-ray diffraction analysis and SEM analysis. The results show that 900 ℃ is the optimum calcination temperature. The absorption spectrum of the sample shows that the absorption peaks of Ho3+ are centered at 536 nm and 645 nm, corresponding to 5I8→5F4 (5S2) and 5I8→5F5 level transitions, respectively. The strong absorption bands of Ho3+ are centered at 940 nm and 982 nm, corresponding to 2F5/2→2F7/2 level transition. The fluorescence spectra of the samples show that the strong emission band of Ho3+ is centered at 1 989 nm, corresponding to 5I7→5I8 level transition. The upconversion spectrum of the sample was tested and the corresponding conversion mechanism was analyzed. Ho∶YbGG can emit strong green and red light under 980 nm LD excitation, which are corresponding to 5F4(5S2)→5I8 and 5F5→5I8 level transitions of Ho3+.