Photoluminescence property and laser performance in Yb-doped Sr1-xGdxF2+x single crystals

3 at.%Yb: Sr1-xGdxF2+x (x = 0,0.01,0.03,0.06,0.09) single crystals are grown by the temperature gradient technique (TGT), where the Gd3+ ions were used as a lattice structural modifier to form a disordered lattice site. The Yb: Sr1-xGdxF2+x crystals maintain cubic structure Fm3m. Specifically, the absorption cross section of 3 at.%Yb: Sr0.97Gd0.03F2.03 crystal was increased by more than 10% compared with that of 3 at.%Yb:SrF2. The emission cross section σem in 3 at.%Yb: Sr0.97Gd0.03F2.03 was 1.21 × 10−20 cm2 at a central wavelength of 976 nm with an enhancement of 11% as compared with that of 3 at.%Yb:SrF2. A direct continuous-wave diode pumped 3 at.%Yb: Sr0.97Gd0.03F2.03 laser could generate an output power of 3.8 W at 1052 nm with an optic-optic efficiency of 46.5% by using output coupler with a transmission T = 3%.