Compact diode-pumped CW and Q-switched 28 μm Er:YLF laser

This paper presents a compact diode-pumped continuous-wave Er:YLF laser emitting radiation at 2.8 µm with output power 2.9 W and slope efficiency 26.2%. Moreover, the Q-switching regime was successfully tested with a Fe:ZnSe polycrystal used as a modulator. Passive Q-switching results in the shortest pulse duration of 21 ns with repetition rate 50 kHz and peak power 252 W.