Mg:Er:Yb:LiNbO_3晶体的结构和光学性质

Structural and Optical Characterization of Mg:Er:Yb:LiNbO_3 LiNbO_3 Crystals

采用阳离子掺杂方法制备了Mg:Er:Yb:LiNbO3晶体,获得了光折变效率高和不影响其它性能的激光晶体.为了探究铌酸锂晶体的微观结构对光学性质的影响,测量了Mg:Er:Yb:LiNbO3晶体的折射率和晶格常数.分析了晶格常数变化的因素和寻常光折射率、非常光折射率变化的因素,这两种性质与Er3+/Yb3+成分的关系不是完全单调变化的,在晶体中,Er3+/Yb3+浓度在1.1—1.2mol%范围内时观察到异常变化.给出了铌酸锂晶体结构对折射率影响的关系,Er3+/Yb3+掺杂LiNbO3晶体的两个主折射率随晶格畸变ca增大而增大.Er3+/Yb3+双掺杂对折射率和晶格常数的变化行为可以用稀土离子浓度影响锂空位浓度和稀土离子在晶体内的位置来解释.

Cations doped LiNbO3crystals Can improve its optical property. Single crystals of Mg： Er：Yb：LiNbO3 with different impurity concentrations have been grown by the Czochralski method. The crystals have high efficiency of photorefraction and still remain other properties. The refractive indices and cell parameters of Er^3＋/Yb^3＋ -doped LiNbO3crystals are measured. By analyzing the dependences of the cell parameters, the extraordinary and ordinary refractive indices, both properties depend in a non-monotonic manner on the Er^3＋/Yb^3＋ content and a singularity was observed at concentrations of 1.1 - 1.2mol% in the crystal. The relation between the structure of Lithium niobate and the refractive indices is obtained. The two principal refractive indices increase with the aberrance c/a. The behavior of refractive indices and unit-cell parameters of Er^3＋/Yb^3＋ -codoped LiNbO3crystals could be explained in terms of the RE^3 ＋ - ion positions in the crystal.