Intra-cavity pumped Ho laser basing on the biaxial YAP host is investigated here for a direct LD pumped compact polarized 2.1 μm laser at room temperature, where the a-cut and b-cut Tm:YAP and Ho:YAP crystals were applied and placed with the same crystallographic orientation. The maximum output power of 2.47 W at 2118 nm was obtained for the b-cut Ho:YAP laser with a slope efficiency of 15.1%, which is higher than that of 1.08 W at 2130 nm for the a-cut Ho:YAP laser with a slope efficiency of 8.9%, attributed to the better spectral overlap between the intra-cavity Tm laser and polarized absorption profile of the Ho:YAP crystal. Scaling up the output power and slope efficiency of the current Ho:YAP laser is predictable via improving heat management of the current structure further by diffusion bonding the Tm:YAP crystal with another un-doped YAP crystal or using a slab Tm:YAP crystal structure for rapid heat transfer.

本文研究了基于双轴YAP主体的腔内泵浦Ho激光器，用于室温下直接LD泵浦紧凑偏振2.1μm激光，其中应用了a切和b切Tm：YAP和Ho：YAP晶体并放置具有相同的晶体学取向。b切割Ho：YAP激光器在2118 nm处获得的最大输出功率为2.47 W，斜率效率为15.1％，高于2130 nm的a切割Ho：YAP激光器在2130 nm处的最大输出功率为1.08W。腔内Tm激光器与Ho：YAP晶体的偏振吸收曲线之间的光谱重叠更好，因此斜率效率为8.9％。通过进一步扩散键合Tm改善电流结构的热管理，可以预测提高当前Ho：YAP激光器的输出功率和斜率效率：