Resonantly pumped single-longitudinal-mode Ho:YAG laser

We demonstrated a 1.9-μm-pumped high-efficiency single-longitudinal-mode Ho:YAG laser with intra-cavity etalons for the first time. By inserting the F-P etalons into the laser cavity, single-longitudinal-mode Ho:YAG lasing was achieved at a wavelength of 2081.2 nm. The maximum single-longitudinal-mode output power of 309 mW was obtained with absorbed pump power of 4.97 W, corresponding to a slope efficiency of 12.77 %. The oscillating wavelength can be tuned (from 2077 to 2081 nm), and single-longitudinal-mode laser is achieved at each wavelength. The M² factors of the single-longitudinal-mode Ho:YAG laser in the x and y directions were 1.18 and 1.2, respectively.