Yb3+离子掺杂浓度对Yb∶YAG晶体发光及荧光寿命的影响

研究了不同掺杂浓度Yb∶YAG晶体的发光特性和荧光寿命.Yb3+在YAG晶体中的掺杂浓度分别为5at%、10at%、20at%、30at%.Yb3+离子掺杂浓度越高，Yb∶YAG晶体的吸收系数越大.采用940 nm波长的LD泵浦源和TRIA X550荧光谱仪，对这一系列掺有不同浓度Yb3+的Yb∶YAG晶体进行了荧光光谱的测定.结果表明:在1030 nm主发光波段的荧光强度以10at%Yb∶YAG的为最强.同时发现它在450 nm-680 nm波段有明显的可见发光，其强度随Yb3+掺杂浓度的增加而迅速地增强.Yb∶YAG晶体的荧光寿命存在浓度猝灭现象，对猝灭机制进行了分析研究，指出浓度猝灭的主要原因是合作发光和痕量稀土离子的上转换发光.

The Influence of Concentration of Yb3+ Ions on Luminescence and Fluorescence Lifetime in Yb : YAG Crystals

The luminescent properties and fluorescence lifetime of Yb∶YAG crystals with different concentration of Yb3+-doped were studied. Yb3+ ions dopant concentration is 5at%,10at%,20at% amd 30at%,respectively. The absorption coefficients of Yb∶YAG crystals become larger with increasing Yb3+ions concentration. Their fluorescence spectra was measured by using LD with a wavelength of 940 nm as the pumping source and TRIA X550 fluorescence spectrum measurement device. The result indicates that lOat% Yb∶YAG crystals possessed the highest fluorescence intensity at the main luminescence band,1030 nm. Simultaneously,the clearly visible luminescence was observed in Yb∶YAG crystals at 450 nm～680 nm bands,and the intensity of which increases rapidly with the increase of Yb3+ ions dopant concentration.There are concentration quenching phenomenon in Yb∶YAG crystals. This phenomenon was studied,and the decrease of fluorescence lifetime is attributed to up-conversion emission of trace rare-earth ions and cooperative luminescence of the Yb3+ ion.