为了提高二极管抽运Yb∶YAG／YAG复合板条激光器的输出光束质量，研究了复合板条内的热透镜效应，分析了复合板条在宽度和厚度方向的热透镜焦距，以及热透镜对谐振腔模式的影响，设计了混合谐振腔，并对该谐振腔输出光束质量进行了分析。采用角抽运复合板条方法，实现了千瓦级Yb∶YAG／YAG复合板条激光器连续运转。采用CCD照相法测量了输出激光的光束质量，在500W连续输出时，光束质量M²因子在板条宽度方向和厚度方向分别优于20和5。实验结果表明，在复合板条激光器中可以采用混合谐振腔获得较好光束质量的激光输出。

To improve the beam quality of a diode-pumped Yb∶YAG/YAG composite slab laser,the thermal lens effect inside the slab was analyzed. The focal lengths of the thermal lens both in thickness and width directions inside the slab were calculated. Its influenceon the resonator mode was also analyzed. A hybrid resonator was designed and the beam quality of its laser output was considered. A continuous wave kilowatts Yb∶YAG/YAG composite slab laser pumped by laser diode was presented,in which the corner-pumped scheme was used. Its beam quality was measured with CCD camera. The M² factors at width and thickness direction were better than 20 and 5 respectively,at an output power of 500W. The results show that the hybrid resonator is suitable for slab laser to obtain a good beam quality output laser.