New Materials for Tunable Lasers in the Near Infrared

There has been considerable recent effort aimed at realising tunable near-infrared laser action in solid-state media. Beyond 1 μm Ni2+ and Co2+ emissions have been mainly studied, and laser action has been achieved in several materials doped with these ions although usually only at low temperatures. Luminescence from Co2+ and Ni2+ in the host material LiGa5O8 is described and evidence is presented for a high quantum efficiency, even up to room temperature. We describe also the results of our lifetime and luminescence measurements on the various active centres in the Mg2SiO4: Cr laser system.