Er^3＋／Yb^3＋：Sr3Y2(BO3)4晶体的光谱和激光性质

Spectra and Laser Properties of Er^(3+)/Yb^(3+):Sr_3Y_2(BO_3)_4 Crystal

采用提拉法生长了双掺Yb3+和Er3+离子浓度分别为18.63%和0.87%(原子分数)的Sr3Y2(BO3)4晶体。利用测量的偏振吸收谱结合Judd-Ofelt理论,拟合得到了该晶体中Er3+离子的偏振和有效J-O参数。测量了Er3+离子4I13/2能级和Yb3+离子2F5/2能级的荧光衰减曲线,并计算了4I13/2能级的荧光量子效率和Yb3+到Er3+的能量传递效率。利用Fuchtbauer-Ladenberg公式计算了Er3+离子4I13/2→4I15/2跃迁的偏振受激发射截面。在平-凹谐振腔中,利用970 nm波长光纤耦合准连续半导体激光端面泵浦1.12 mm厚的该晶体,当输出镜透过率为1.5%时,获得了最大输出功率为1.3 W和斜率效率为20%的1560 nm附近的激光输出。结果表明,Er3+/Yb3+:Sr3Y2(BO3)4晶体是一种优良的1.5～1.6μm波段激光的增益介质。

An Er^3＋/Yb^3＋ ： Sr3 Y2 （ BO3 ） 4 crystal with Yb^3＋ and Er^3＋ concentrations of 18.63% and 0.87% was grown by the Czochralski method. The Judd-Ofelt theory was used to analyze polarized absorption spectra and then to calculate the polarized and effective J-O parameters. The fluorescence decay curves of 4113/2 and ^2F5/2 multiplet for Er^3＋ and Yb^3＋ ions, respectively, were measured. The fluorescence quantum efficiency of ^4 I13/2 muhiplet and energy transfer efficiency for Yb^3＋ to Er^3＋ were estimated. Polarized stimulated cross-sections of ^4 I13/2→^4 I15/2 transition for Er^3＋ ions were obtained by the Fuchtbauer-Ladenberg formula. The end-pumped by a fiber-coupling quasi-cw diode laser at 970 nm, laser around 1560 nm with output power and slope efficiency up to 1.3 W and 20% , respectively, was obtained from a 1.12 mm-thick Er^3＋/ Yb^3＋ ：Sr3Y2 （BO3）4 crystal in a hemispherical cavity with the output coupler transmission of 1.5%. The results showed that this crystal was a good gain medium for 1.5 - 1.6 μm laser.