Thermal Properties of Yb:YAG Crystal and Its Influence on Laser Properties

对于中频感应加热提拉法（Czochralski Method）生长的高掺杂浓度（原子数分数0.30）Yb:YAG晶体，经退火后采用差示扫描量热计法测量了晶体的比热容，通过激光脉冲法测量了不同掺杂浓度（原子数分数0.05～0.30）Yb:YAG晶体的热扩散率和热导率。实验表明，随着Yb~(3+)离子浓度增加，Yb:YAG晶体在300 K温度下的导热性能有明显的降低，原子数分数为0.30的Yb:YAG晶体的激光实验表明，高掺杂浓度Yb:YAG晶体热导率的降低导致了激光阈值的增加。The highly doped Yb:YAG (fraction of atomic number 0.30) laser crystals are grown by Czochralski method heated by medium frequency induction. After annealing, the specific heat capacity of Yb:YAG single crystals is measured by the means of differential scanning calorimetric method (DSC), and the thermal conductivity and diffusivity of Yb:YAG crystal with different doping concentrations (fraction of atomic number 0.05～0.30) is obtained by the pulsed laser technique. The experiments suggest that at room temperature (300 K), thermal conductivity of Yb:YAG crystals decreases greatly with increasing Yb~(3+) content in the crystals. The experiments of laser performance of highly doped Yb:YAG (fraction of atomic number 0.30) crystals show that, the low thermal conductivity in the highly doped Yb:YAG crystals leads to high threshold for lasing