演示了激光二极管(LD)端面抽运Yb∶YAG薄片固体激光器,抽运源是美国相干公司(COHERENT)光纤耦合输出半导体激光器,光纤输出芯径为800 μm,在940 nm处最大输出功率为13.56 W,由于光纤输出芯径较大,不利于抽运光和振荡光的模式匹配,为了得到较小的抽运光斑,采用了焦距比为30∶12的耦合透镜组压缩入射到晶体端面的抽运光光腰半径,晶体为原子掺杂浓度8 at.-%,几何尺寸为φ7 mm×1.6 mm国产Yb∶YAG晶体,整个实验装置采用温差电致冷(TEC)和循环水冷却方式,实验中得到了3.06 W的连续激光输出,激光器的斜率效率为33.1%,测得M2因子在x和y方向分别为1.54和1.73,具有良好的光束质量。

A laser diode (LD) end-pumped Yb∶YAG (Yb∶Y3Al5O12) chip laser has been demonstrated. The pumping source is a fiber coupled laser diode array with maximum output power of 13.56 W at 940 nm. The diameter of the fiber is 800 μm. Two lenses with focal length ratio of 30∶12 have been used to compress the pumping light into the laser crystal. 3.06 W continuous wave (CW) output power was obtained from the 8 at.-% doped, 1.6 mm thick Yb∶YAG crystal, the whole experiment set was cooled by thermoelectric cooler (TEC) and cooling water, slope efficiency was 33.1%, the M2 values were measured to be 1.54 and 1.73 in the x and y directions respectively.