端面研磨Nd:YAG晶体棒热透镜焦距测量

主要分析和测量端面研磨凹面的Nd:YAG激光晶体棒的热透镜焦距。实验通过He-Ne光测试法,分别测量了不同功率下的端面研磨和未研磨晶体棒的热透镜焦距,并通过作图比较二者的热透镜焦距随泵浦功率变化情况,得出随着泵浦功率的增大,热透镜焦距逐渐减小的结论。文中对未研磨晶体棒热透镜焦距进行了理论和实验值的比较,曲线情况基本相符,故根据理论计算出补偿热透镜效应所需要的晶体棒的研磨半径。由于通过理论计算得出的研磨半径在实验过程中出现了出光阈值高,输出功率降低等一些现象,不利于生产的需要,故在实际经验的指导下,增大了晶体棒的研磨半径。结论指出端面研磨晶体棒的方法在一定条件下能对激光晶体棒的热透镜效应进行补偿,对大功率固体激光器的研发有一定积极作用。

Thermal lens focal length measurement of grinding extremity Nd:YAG laser rod

Thermal lens focal length of Nd: YAG laser rod,which extremity is ground,is analyzed and measured in this work.We measured the focal length with grinding extremity and normal rod under different power by He-Ne light test method,and drew comparing pictures.The conclusion is that thermal lens focal length decreases gradually,with the increasing of pump power.The paper compared the theoretical and the experimental value of normal rod,and the curve is almost the same.So according to the theory,it calculated the grinding radius to compensate thermal lens effect.In the experiment,the processed laser rod appeared out of light with higher threshold,output power reduction and so on.This was not beneficial to the needs of the production,so increased the grinding radius by the practical experience.It pointed out that laser rod with grinding extremity could compensate thermal lens effect in some level.There was a positive effect for the development of high power solid-state laser.