Growth, spectroscopic properties and efficient laser action of an Yb_0.09Lu_0.13Gd_0.78Ca₄O(BO3)₃ crystal

A new Yb-ion laser crystal of Yb0.09Lu0.13Gd0.78Ca4O(BO3)(3) was grown by using the Czochralski method. The polarized absorption and emission spectra with respect to the three principal optic axes were obtained, with the maximum cross-section of the zero-phonon absorption and emission determined to be 1.90 x 10(-20) cm(2)(E//X) and 1.55 x 10(-20) cm(2)(E//X), respectively. An analysis of gain curves indicates the superiority of this crystal to Yb:GdCOB in realizing laser operation at the zero-phonon line of around 977 nm. Efficient continuous-wave laser action was achieved in the main emission band, generating an output power of 13.53 W with an optical-to-optical efficiency of 64.6%, and the slope efficiency amounting to 71%.