Crystal growth of YCa4O(BO3)3 and its orientation

The growth of YCa4O(BO3)(3) (YCOB), one of the rare-earth calcium oxyborate family of crystals that melts nearly congruently is reported. Typical crystals produced in our laboratory are about 40 mm in diameter and 150 mm long with good optical quality. The crystal has good potential to be used for self-frequency doubling due to its excellent combination of nonlinear and laser properties. The single crystal growth of YCOB with different rare-earth substitutions is presented. We find that the substitution limit is reduced with either an increase or decrease in the ionic size of the substituted rare-earth element. The melt also moves further away from congruently melting with these substitutions. YCOB belongs to monoclinic crystal system. The orientation relationship between the crystallographic axes (a, b, c) and optical indicatrix axes (X, Y, Z) is discussed. (C) 1999 Elsevier Science B.V. All rights reserved.