Comparison of laser performance of Yb:YCa4O(BO3)3 crystals cut along the principal optical axes

Abstract

Efficient high-power continuous-wave laser operation is demonstrated with Yb:YCa4O(BO3)3 crystals cut along the X, Y, and Z principal axes, end pumped by a high-power diode. Highest output powers of 6.3–7.3 W are generated, with slope efficiencies in the range of 73–83%. The standard behavior characterized by fixed linear polarization of the output and decreasing oscillation wavelength when increasing the output coupling was observed only for the X-cut crystal; the Y-cut crystal led to the polarization state changing and coexistence, while the Z-cut crystal resulted in dual-band laser operation with a fixed polarization state.