Growth and Characterization of Yb~(3+)-doped (Lu,Y)AlO_3 Fiber Single Crystals Grown by the Micro-Pulling-Down Method

摘要

Yb~(3+)-doped (Lu,Y)AlO_3 single crystals have been grown by the micro-pulling-down method with a radio-frequency healing system. Starting melt compositions of Lu_xY_(0.9-x)Yb_(0.1)AlO_3 were varied with x = 0.1, 0.2, 0.35, and 0.4. The best Yb~(3+) -doped (Lu,Y)AlO_3 single crystals were obtained applying a pulling rate of 0.12mm/min. To investigate the compositional homogeneity, the effective segregation coefficient of Lu and Yb ions was estimated k_(eff) = 1.02 and 1.05 for Lu_(0.2)Y_(0.7)Yb_(0.1) AlO_3 crystal, respectively. Absorption, radio-luminescence and luminescence decay kinetic of Yb~(3+) -doped (Lu,Y)AlO_3 was investigated for room temperature conditions and found to be similar to that of Yb~(3+)-doped YAlO_3. Very fast charge transfer luminescence of Yb~(3+) in the near ultraviolet to visible spectral range and the high density of the LuAlO_3 make this material a promising candidate for fast scintillators.