Defect structure and optical damage resistance of In:Er:LiTaO_3 crystals

摘要

LiTaO_3 single crystals double-doped with 1.0 mol% Er~(3+) and various In~(3+) ions (In:Er:LiTaO_3) were grown by the Czochralski method from a congruent melt (C_(Li)/C_(Ta)=0.946). Ultraviolet-visible absorption spectra were measured and discussed in terms of the defect structure. Threshold concentration of In~(3+) ion is 3.0 mol%. Optical damage resistance of In:Er:LiTaO_3 crystals were characterized by the transmitted beam pattern distortion method. Optical damage resistance of In:Er:LiTaO_3 crystals significantly increases when the concentration of In~(3+) ion exceeds its threshold concentration. The optical damage resistance magnitude of In(3.0mol%):Er:LiTaO_3 crystal is two orders higher than that of Er:LiTaO_3 crystal. The optical damage resistance could be well understood in view of defect structure.