Abstract
We have grown an organic nonlinear optical crystal, 4-dimethylamino-N-methyl-4-stilbazolium tosylate(DAST) by using slow coollng method. We have changed the growth rate from 0.14mm/day to 1.2mm/day. High quality crystal could be obtained for the slowest growth rate. This crystal exhibited largest hardness because of the highly oriented molecular arrangement.
