2μm Cr,Tm,Ho:YAG激光热退偏效应的数值模拟及实验研究

Numerical simulation and experimental study of thermal-induced-depolarization in 2μm Cr,Tm,Ho:YAG laser

理论分析了Cr,Tm,Ho:YAG激光晶体的热退偏效应,模拟计算了该晶体棒端面退偏度的分布,并进行了偏光干涉实验验证.结果表明,数值模拟和实验研究结果完全一致,热致退偏效应随抽运能量增大而增强,退偏度分布呈十字形,最大退偏度发生在晶体棒端面上与起偏器偏振方向成45°方位处.以此提出了高能量Cr,Tm,Ho:YAG激光器的热退偏补偿方法,获得了激光脉冲能量提高24%以上的实验效果.

The theory of thermal-induced-depolarization is analyzed,the distribution of depolarization is numerically simulated,and the result is verified by the polarized light interferometry.The experimental result is coincident with the numerical simulation,which shows that the distribution of depolarization in the cross section of Cr,Tm,Ho：YAG is crisscross,and increases with the pump energy increasing.The direction of the worst depolarization is 45°with respect to the polarization direction of the polarizer.According to the numerical simulation,we employ aλ/4-plate to compensate the depolarization of a high-energy Cr,Tm,Ho：YAG laser.The pulse energy increases by 24%after compensation.