Comparison in 2.1 μm laser performances among Tm:YLF laser intra-cavity pumped Ho:YLF, Ho:YAG, and Ho:YAP lasers

We demonstrate lasing properties of the c-cut Ho:YLF, Ho:YAG and c-cut Ho:YAP laser intra-cavity pumped by a σ-polarized Tm:YLF laser within a compact linear cavity. Owing to the weak thermal lens of the YLF-based host media, maximum Ho laser power of 8.63 W at 2063.1 nm, with a slope efficiency of 25.2% and M2 of 1.41 was obtained in the Ho:YLF laser. Besides, maximum output power of 7.45 W at 2122.2 nm and 3.55 W at 2129.5 nm were obtained with the Ho:YAG and Ho:YAP lasers, respectively, with corresponding slope efficiencies of 23.1% and 11.8%.