高重复率半导体激光抽运Nd：YAG放大器激光特性的实验研究

实验研究了高重复率、大功率半导体激光二极管阵列（LDA）侧面环绕抽运的Nd：YAG激光放大器的放大特性、热焦距变化和热致双折射效应引起的退偏特性。偏振光绎千赫兹高功率单通激光放大器，获得约3倍的光脉冲能量放大，脉冲宽度基本保持不变，其输出的P分量与S分量的能量比趋于常数3：1，实验测得的能量放大倍率及放大光束的椭圆偏振度与理论预期吻合很好。

In this paper, the characteristics of laser diode array (LDA) side-pumped high repetition Nd∶YAG amplifier were studied. The thermal focal length of Nd∶YAG rod and the thermal depolarization to laser beam caused by thermally induced birefringence in gain medium were detected. A magnification of three was obtained in this kHz high power Nd∶YAG amplifier, while the pulsewidth was kept almost the same as that of incident pulse. In the amplification output pulse, the energy ratio of P polarization to S polarization was trend to 3∶1. The experimental results of amplification output pulses tend to be consistent with the theoretical anticipation as the pump power increasing.