高掺杂浓度Yb∶YAG晶体的生长及激光性能

GROWTH OF HIGH DOPING Yb∶YAG AND ITS LASER PERFORMANCE

用引上法生长了 30 %Yb∶YAG(摩尔分数 ,下同 )晶体 ,研究了晶体的生长工艺参数和退火工艺参数 ;用 940nm的吸收系数表征了Yb3 + 离子在Yb∶YAG晶体中的分布情况 ,结果表明 :Yb3 + 离子在Yb∶YAG晶体中分布均匀 .研究了晶体微片的激光特性 ,用钛宝石激光器泵浦 30 %Yb∶YAG微片 ,获得了 1.0 5 3μm的高效激光输出 .

Yb∶YAG crystal with Yb 3+ doping level up to 30% (in mol) was grown by CZ method. The growth parameters and annealing conditions are studied. The optimal growth conditions were found to be as follows: rotation rate is 15 r/min, pull rate is 0.8 mm/h. The growth atmosphere was nitrogen or argon. The optimal annealing processing is as follows: in oxygen atmosphere Yb∶YAG crystal boule is fired at 1 600 ℃ for 36 h, and then cools to room temperature at a rate of 10 ℃/h. After annealing, the crystal changes from blue to colorless, suggesting that Yb 2+ and color center are eliminated. The distribution of Yb 3+ in Yb∶YAG was characterized by the intrinsic absorption performances of Yb∶YAG at 940 nm. The result shows that 30%(mol) Yb∶YAG crystal is uniformity. The purpose of growing high doping Yb∶YAG is to realize Yb∶YAG microchip laser with high power and high efficiency, thus the laser performance of 30%(mol) Yb∶YAG microchip was investigated. The laser resonator is formed from flat_flat cavity, and CW output at 1.053 μm is obtained with Ti: sapphire laser (940 nm) pumped 5mm×5mm×0.25mm Yb∶YAG chip.