Nd:YAG调Q激光器失稳现象的理论及实验研究

报道了一种Nd:YAG调Q短脉冲激光器失稳现象的理论分析及实验研究。短脉冲调Q激光器运行过程中，会有多种因素导致其不能稳定输出符合目标值的脉冲激光，即出现失稳现象。实验过程中发现，输出镜处的干扰光会导致短脉冲激光器出现失稳现象。在理论基础上，对外界干扰光对短脉冲调Q激光器输出光特性的影响进行了模拟计算，并进行了实验验证，分别从能量和脉宽两个特性进行讨论。结果表明:干扰能量越大，造成失稳现象越严重，干扰脉冲能量为60 mJ时，短脉冲调Q激光器输出能量损失达15%以上，脉宽展宽至1.15倍以上；干扰脉冲注入时间节点越靠后，失稳现象越严重，在短脉冲调Q激光器的泵浦末端，即调Q开关打开前注入能量为60 mJ、脉宽为10 ns的干扰脉冲时，短脉冲调Q激光器可输出能量损失达到80%。

Theoretical and experimental study on Nd:YAG Q-switched laser instability phenomenon

The theoretical analysis and experimental study of the instability phenomenon of a Nd:YAG Q-switched short pulse laser was demonstrated. During the operation of the short pulse laser, there were many factors that can cause the instability phenomenon. During the experiment it was found that the interference pulse which can enter into the cavity though the output mirror can cause the instability of the short pulse laser. Based on the basis of thory, the influence of external interference light on the output light characteristics of short pulse Q-switched laser was simulated and verified by experiments.The characteristics of energy and pulse width were discussed respectively. The results show that the greater the energy of interference pulse is, the more serious the instability phenomenon is. When the interference pulse energy is 60 mJ, the loss of output energy of the short pulse laser can be more than 15%. The pulse width is 1.15 times of the original, the instability phenomenon is also more serious at the pump end of the short pulse Q-switched later. When the input energy is 60 mJ the pulse width is 10 ns, the loss of output energy of the short pulse Q-switched laser reaches 80% of the original.