The 2.8 μm laser properties of Er3+ doped CaF2 crystals

Laser emission at 2.8 mum in Er3+:CaF2 crystals is analysed for different excitation pump wavelengths: 800, 968 and 1545 nm. The best laser performance is obtained for 968 nm Ti:sapphire laser excitation with an absorbed pump power at threshold of 23 mW and a slope efficiency of 30%. Laser emission under 1545 nm excitation into the terminal level I-4(13/2) of the laser transition is obtained due to efficient upconversion energy transfers. (C) 2002 Elsevier Science B.V. All rights reserved.