Qualitative improvement in the lasing performance of PbGa2S4 : Dy3+ crystals through Na+ doping

We have studied the lasing properties of lead thiogallate crystals codoped with dysprosium and sodium ions. Sodium doping has been shown to have an advantageous effect on the optical and lasing properties of lead thiogallate crystals. At a pump pulse duration of 1.5 ms, output pulse energies up to 15 mJ have been obtained at a slope efficiency of up to 4%. Cascade lasing on two Dy³⁺ transitions, at 4.3, 4.5, 4.65, 5.2, 5.3 and 5.4 μm, has been demonstrated.