CaF2:Yb laser ceramics

CaF2:Yb fluoride laser ceramics, prepared by hot-forming, exhibit the same optical properties as starting single crystals. Slope efficiency of the Ca0.95Yb0.05F2.05 is equal to 35% in the pulsed mode of laser operation. Decrease of ytterbium concentration in CaF2:Yb samples down to 3 mol.% resulted in the essential improvement of Ca0.97Yb0.03F2.03 thermal conductivity from 3.5 to 4.5 W/m K, but slightly decreased (down to 30%) slope efficiency of the samples under both pulsed and CW mode of operation. Alternative hot-pressing synthesis of CaF2:Yb fluoride laser ceramics provided materials with superior mechanical properties (microhardness H = 3.2 GPa and fracture toughness K-1C = 0.65 MPa m(1/2)) in comparison with hot-formed and/or single crystal CaF2:Yb specimens. For the first time, lasing has been observed for the novel aforementioned hot-pressed CaF2:Yb ceramics. (c) 2012 Elsevier B.V. All rights reserved.