High efficiency continuous wave and Q-switched laser based on an orthorhombic Yb:GdScO3 crystal in the (112) direction with a broad emission bandwidth of 93 nm

Herein, we demonstrate a broad emission bandwidth of 93 nm with the orthorhombic Yb:GdScO3 crystal along the (112) direction, which is about 3.7-7.8 times wider than that of cubic sesquioxide crystals. By investigating the distorted RE2Ox ligands and their association with lattice vibrations, the inhomogeneous broadening was found to be dependent on local crystal polarization and electron-phonon interaction. Moreover, the (112) direction sample has a small emission cross-section of 0.42 x 10-20 cm2 and better thermal symmetry, which allow it to achieve a continuous wave (CW) laser with a slope efficiency of 62%, a passively PdSe2 Q-switched laser with an average output power of 1.69 W, a slope efficiency of 43%, and a pulse width of 272.9 ns. We believe this to be the first investigation of the effective spectral broadening and Q-switch operations based on the orthorhombic Yb:GdScO3 crystal in the (112) direction. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement