双掺Er^(3+)/Yb^(3+)∶Sr_3La_2(BO_3)_4晶体的生长与光谱特性

Growth and Spectral Characteristics of Er^(3+)/Yb^(3+)∶Sr_3La_2(BO_3)_4 Crystal

采用提拉法生长了尺寸为20mm×30mm的Er3+/Yb3+∶Sr3La2(BO3)4晶体,研究了Er3+/Yb3+∶Sr3La2(BO3)4晶体的吸收光谱和荧光光谱。根据Judd-Ofelt理论分析并计算了辐射跃迁几率、辐射寿命、荧光分支比等光谱参数,获得的唯象参数为:Ω2=15.59×10-20cm2,Ω4=2.25×10-20cm2,Ω6=1.49×10-20cm2。在Er3+/Yb3+∶Sr3La2(BO3)4晶体中Er3+在1533nm处发射跃迁截面为7.88×10-21cm2,Er3+的4I13/2→4I15/2能级跃迁的荧光寿命和辐射寿命分别为0.728ms和4.24ms,结果表明Yb3+对Er3+有敏化作用,提高了对泵浦光的吸收能力,Er3+/Yb3+∶Sr3La2(BO3)4晶体可望作为1.55μm波段的一种有潜力的激光材料。

Yb3＋ and Er3＋ co-doped Sr3La2（ BO3） 4 crystal with dimensions of 20 mm ×30 mm was grown by Czochralski method. The spectral properties of Er3 ＋ in Er3 ＋ /Yb3 ＋ ∶ Sr3La2 （ BO3 ） 4 crystal were investigated,and their spectroscopic parameters such as radiative transition probabilities,radiative lifetime and fluorescent branching ratios were calculated based on the J-O theory. The oscillator intensity parameters were calculated to be Ω2 = 15. 59 × 10-20 cm2,Ω4 = 2. 25 × 10-20 cm2,Ω6 = 1. 49 × 10-20 cm2. The calculated emission cross section was estimated to be 7. 88 × 10-21 cm2 at 1533 nm. The fluorescence lifetime and radiative lifetime of the Er3 ＋ （ 4I13/2→4I15/2 transition） was measured to be 0. 728 ms and 4. 24 ms,respectively. The result shows that the Yb3 ＋ as the sensitizer can enhance the absorption efficiency,the Er3 ＋ /Yb3 ＋ ∶ Sr3La2（ BO3） 4 crystal may be regarded as 1. 55 μm a promising laser material.