Spectroscopic and laser properties of a broadly tunable diode-pumped Tm3+ :CaF2-SrF2 laser

The spectroscopic and laser properties of mixed fluoride Tm:CaF2-SrF2 crystals were investigated. The 1.9 mu m radiation was obtained in two samples with Tm3+ ion doping concentrations of 1.0 mol% and 2.0 mol% under laser diode pumping at 763 nm. The highest slope efficiency of 32.5% and the widest laser tuning range of 232 nm (1761-1993 nm) were demonstrated with the 1%-doped sample. The maximal output power amplitude of 3.4 W at 1902 nm for an absorbed pump power amplitude of 13.8 W was demonstrated with the 2%-doped sample.