设计了一台二极管泵浦的具有新型四通泵浦结构及接触式水冷装置的Yb∶YAG薄片激光器.激光泵浦源采用中心波长为940 nm的二极管激光器,利用多模光纤进行耦合输出.YAG晶体Yb3+离子掺杂浓度为10%,几何尺寸为直径10 mm,厚度500 μm.激光晶体的散热装置采用自来水直接冷却,自来水通过铜热沉中打通的V型槽与薄片晶体直接接触.泵浦耦合系统采用聚焦透镜和一对直角棱镜的组合实现四通泵浦,聚焦透镜规格为直径50 mm,焦距50 mm.模拟了谐振腔的稳定性及不同腔长条件下所对应的激光光斑半径,设计了不同腔型的Yb∶YAG薄片激光器.在F-P腔中采用透过率为5%的输出耦合镜,获得了最高功率为3.28W的1 031 nm连续激光输出,光束质量因子M2x=1.79, M2y=1.86,斜效率为20.5%.

A Yb∶YAG thin disk laser with a novel four-pass pumped structure and direct water cooling device was designed. The multi-mode pump radiation was from a fiber-coupled 940 nm diode laser. The Yb∶YAG disk with 10 mm diameter and 500 μm thickness was employed. The Yb3+ atom fraction was 10%. The direct cooling arrangement was put forward,tap water was contacted with the Yb∶YAG through a V groove. The four-pass pump coupling system was well designed with a pair of rectangular prism and a focusing lens which had a diameter of 50 mm and focus of 50 mm. Then simulated the stability of the resonator and calculated the radius of the laser spot in different position of the resonator with the different cavity length. Different types of laser cavity were set up. With the output coupling rate of 5%,the maximum output power of 3.28 W at 1 031 nm was obtained in F-P resonator. The beam quality M2x=1.79, M2y=1.86. The slope efficiency was 20.5%.