Comparison of Yb:YAG crystals grown by CZ and TGT method

摘要

Five atomic percent Yb:YAG laser crystals have been grown by Czochralski (CZ) and temperature gradient technique (TGT) method. The absorption spectra of as-grown and annealed Yb:YAG crystals have been investigated. There is no Yb~(2+) and color center absorption in TGT-grown Yb:YAG crystals; the absorption peak of CZ-grown Yb:YAG crystals after O_2-annealing at 255 nm is attributed to Fe~(3+) ions. The longitudinal distribution of Yb~(3+) ions has also been studied; TGT-grown Yb:YAG crystal has a larger distributing inhomogeneity of Yb~(3+) although it is large sized.