采用热透镜焦距的理论计算与实验测量相比较的研究方法,得到一种端泵固体激光器出激光时的在线测量方法.通过建立热透镜等效腔模型以及腔型分析求解得出腔内光束束腰半径,用刀口法测出DPL腔外的远场发散角,根据发散角与透镜变换前后的束腰关系,得出LD端面泵浦Nd∶YAG激光器中的热透镜焦距.结果表明,通过上述方法所得结果与理论计算的热透镜焦距吻合,证实此方法准确、可行.

A new method to measure the thermal lens of the solid state laser is presented while laser is outputted by the comparation with the theory result and the experiment. The thermal lens can be achieved by experiment at first, then calculated out by the theory analysis. The thermal lens resonance cavity model is set up at first,then the waist of the laser is calculated and the DPL′s far field divergence angle can be measured by the edge of knife method .In the end , using the laser′s spread and lens′ transfer theory , the focus of the thermal lens is known. This is a new method to measure the focus of the thermal lens of the end-pumped Nd∶YAG Laser. The result shows that the theory value is in good agreement with the experiment value. It shows that this method is correct and can be operated easily. Because the experiment is done when the DPL outputs laser , the focus of the thermal lens is gotten according to the circumstance of the laser and the precision is high.