Growth and spectral properties of Pr, Yb, Ho:GdScO₃ crystal

In order to explore and develop new crystal materials in the 2.7-3.0 mu m band, Pr, Yb, Ho:GdScO3 crystal are successfully grown by the Czochralski method for the first time. X-ray diffraction measurement is performed to obtain powder diffraction data. Raman spectra aree measured and the vibration peaks are identified. The transmission spectrum, emission spectrum and fluorescence lifetime of Pr, Yb, Ho:GdScO3 crystal are also characterized. The center of the strongest absorption band is at 966 nm with a half-peak width of 90 nm, which comes from the transition of Yb3+: F-2(7/2) -> F-2(5/2). The absorption cross section of Yb3+ is calculated and the values at 966, 973, 985 nm are 0.62x10(-20), 0.60x10(-20) and 0.58x10(-20) cm(2) respectively. The maximum emission peak is at 2850 nm and the half-peak width is 70 nm, the lifetimes of Ho3+:I-5(6) and I-5(7) are measured to be 1094 and 56 mu s respectively, and the emission cross section at 2850 and 2935 nm are calculated to be 3.6x10(-20) cm(2) and 1.21x10(-20) cm(2), respectively. Comparing with Yb, Ho: GdScO3 crystal, the absorption peak of Yb3+ and the emission peak are both broadened, which are related to the increase of crystal disorder. The lifetime of the lower energy level decreases significantly. Furthermore, the energy transfer mechanism between and Pr3+ is analyzed, and the energy transfer efficiency between Ho3+:I-5(7) and Pr3+:F-3(2)+H-3(6) is calculated to be 99%, which is higher than those in other materials. All the results show that Pr, Yb, Ho:GdScO3 crystal is an excellent 2.73 mu m laser material, and is easier to achieve laser output than Yb, Ho:GdScO3 crystal.