Optical study of single crystals grown by the Czochralski method from Yb~(3+)-doped (Gd_(1-x)Y_x)_2SiO_5 solid solution

摘要

Yb~(3+)-doped crystals were grown by the Czochralski method from (Gd_(0.5)Y_(0.5))_2SiO_5 melt employing seeds cut out from single crystals of Yb:Gd_2SiO_5 and Yb:Y_2SiO_5. XRD analysis revealed that the structure of the solid solution crystals grown is consistent with the structure of the seed, namely C2/c for the Yb:Y_2SiO_5 seed and P2_1/c for the Yb:Gd_2SiO_5 seed. Optical absorption spectra, emission spectra and luminescence decay curves were recorded at 10 K and 300 K. Analysis of gathered spectroscopic data made it possible to evaluate radiative transition rates for the ~2F_(5/2) multiplet of Yb~(3+) in the two structures and to assess crystal field splitting of multiplets involved in radiative transitions. It has been concluded that transition intensities and relaxation dynamics of Yb~(3+) in the systems studied are similar but the intensity distribution of emission and absorption bands depends significantly on the system structure. This feature, combined with inhomogeneous broadening of spectral lines, may be advantageous for the tailoring of lasers employing ytterbium-doped crystals for specific applications.