A diode-pumped Q-switcheda-cut Tm:YAP laser with an average output power of 13 W

We report experimental results on a highly efficient Q-switched a-cut Tm:YAP laser working at 1.99 µm. A fiber-coupled laser diode (LD) working at 795 nm was used to pump a Tm:YAP (diameter 5 mm × 9 mm) crystal with 3% Tm3+ doping. Under the input pump power of 44.5 W, it delivered a polarized pulsed laser output with a repetition rate of 10 kHz at 1.99 µm. The maximum output power was 13.29 W, corresponding to a slope efficiency of 36.5% and optical-to-optical conversion efficiency of 29.9%. The influences of curvature and transmittance of the output mirror on the laser output are analyzed and validated by experiments, and the results are of benefit for optimization of the laser cavity.