Growth, structure, spectroscopic and continuous-wave laser properties of a new Yb: GdYCOB crystal

A new mixed crystal of Yb0.14Gd0.71Y0.15COB was grown by the Czochralski method. The polarized absorption spectra of the crystal were measured, and the absorption cross sections were determined to be 0.81 × 10−20 (E//X), 0.98 × 10−20 (E//Y) and 0.74 × 10−20 cm2 (E//Z) at 977 nm. The fluorescence bands corresponding to 2F5/2 → 2F7/2 transition were identified in 970–1125 nm wavelength range with four peaks located at 977, 1003, 1030 and 1081 nm. The emission cross-sections were calculated by a combination of the reciprocity method (RM) and Füchtbauer-Ladenburg (F-L) method. The fluorescence lifetime was recorded to be 2.59 ms. Effective continuous-wave (CW) laser operation was realized with this crystal, with a maximum laser output power of 9.28 W and a slope efficiency of 40.1% for laser operation. Our study may open up new opportunities toward the research and development of high-performance laser crystals.