Performance of diode-pumped Tm3+:Sc2SiO5 crystal passively Q-switched 2 μm laser

A diode-pumped passively Q-switched Tm3+:Sc2SiO5 laser with a single-walled carbon nanotube saturable absorber is demonstrated for the first time. The maximum average output power of 189 mW has been achieved at 1970 nm under an absorbed pump power of 4 W. The minimum pulse width of 442 ns was obtained at a repetition rate of 55.6 kHz, corresponding to the highest peak power of 7.7 W and single pulse energy of 3.4 μJ, respectively.