Spectroscopic properties and high-power laser operation of Yb0.14:Y0.77Gd0.09Ca4O(BO3)3 mixed crystal

• A new mixed rare-earth calcium oxyborate Yb-ion laser crystal is developed.
• Spectroscopic properties are studied for the mixed oxyborate Yb-ion crystal.
• CW output power of 23.0 W is produced with the mixed oxyborate crystal in a simple end-pumed plano-concave resonator.

We report, for the first time to our knowledge, on the spectroscopic properties and continuous-wave laser performance of Yb0.14:Y0.77Gd0.09Ca4O(BO3)3, a mixed rare earth calcium oxyborate Yb-ion crystal. Under simple end-pumping conditions with a 976-nm diode, efficient CW laser operation was demonstrated at room temperature, producing an output power of 14.1 W at 1084.4 nm with an optical-to-optical efficiency of 48%; while operating around 1045 nm, the laser could generate an output power as high as 23.0 W, with optical-to-optical and slope efficiencies amounting, respectively, to 57% and 70% with respect to incident pump power. The polarized absorption and emission cross sections are also presented. The impressive results demonstrated reveal the great potential of these mixed oxyborates in developing new promising Yb-ion laser crystals.