Optimum fluorescence emission around 1.8μm for LiYF_4 single crystals of various Tm^(3+)-doping concentrations  

作　　者：李珊珊 夏海平 符立 董艳明 谷雪梅 章践立 王冬杰 张约品 江浩川 陈宝玖 

机构地区：[1]Key Laboratory of Photo-electronic Materials, Ningbo University [2]Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences [3]Department of Physics, Dalian Maritime University

出　　处：《Chinese Physics B》2014年第10期551-556,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.51472125 and 51272109);the Natural Science Foundation of Ningbo City,China(Grant No.201401A6105016);K.C.Wong Magna Fund in Ningbo University,China(Grant No.NBUWC001)

摘　　要：In this paper, optical spectra of LiYF4 single crystals doped with Tm3＋ ions of various concentrations are reported. The emission intensity at 1.8 ktm first increases with increasing Tm3＋ concentration, and reaches a maximum value when the concentration of Tm3＋ is about 1.28 mol%, then it decreases rapidly as the concentration of Tm3＋ further increases to 3.49 mol%. The emission lifetime at 1.8 p.m also shows a similar tendency to the emission intensity. The maximum lifetime of 1.8 μm is measured to be 17.68 ms for the sample doped with Tm3＋ of 1.28 mol%. The emission cross section of 3F4 level is calculated. The maximum reaches 3.76 × 10 -21 cm2 at 1909 nm. The cross relaxation （3H6, 3H4 →3 F4, 3F4） between Tm3＋ ions and the concentration quenching effect are mainly attributed to the change of emission with Tm3＋ concentration. The largest quantum efficiency between Tm3＋ ions is estimated to be ,-147% from the measured lifetime and calculated radiative lifetime. All the results suggest that the Tm3＋/LiYF4 single crystal may have potential applications in 2 μm mid-infrared lasers.In this paper, optical spectra of LiYF4 single crystals doped with Tm3＋ ions of various concentrations are reported. The emission intensity at 1.8 ktm first increases with increasing Tm3＋ concentration, and reaches a maximum value when the concentration of Tm3＋ is about 1.28 mol%, then it decreases rapidly as the concentration of Tm3＋ further increases to 3.49 mol%. The emission lifetime at 1.8 p.m also shows a similar tendency to the emission intensity. The maximum lifetime of 1.8 μm is measured to be 17.68 ms for the sample doped with Tm3＋ of 1.28 mol%. The emission cross section of 3F4 level is calculated. The maximum reaches 3.76 × 10 -21 cm2 at 1909 nm. The cross relaxation （3H6, 3H4 →3 F4, 3F4） between Tm3＋ ions and the concentration quenching effect are mainly attributed to the change of emission with Tm3＋ concentration. The largest quantum efficiency between Tm3＋ ions is estimated to be ,-147% from the measured lifetime and calculated radiative lifetime. All the results suggest that the Tm3＋/LiYF4 single crystal may have potential applications in 2 μm mid-infrared lasers.

关 键 词：Tm3＋-doped LiYF4 crystal cross relaxation fluorescence emission 1.8 μm 

分 类 号：O482.31[理学—固体物理]