PURPOSE:To surely and stably obtain a crystal having high resistance to damage due to a laser by subjecting a growth soln. for a water soluble optical single crystal to a sufficient pretreatment prior to growth, thereby decreasing org. impurities as far as possible. CONSTITUTION:The water soluble optical single crystal having resistance to scratching by the high-output laser is grown by the following two stages A and B: (A) A 1st stage consisting in removing the org. impurities from the growth soln. 10 to be used at the time of growing the water soluble optical single crystal by subjecting said soln. to the pretreatment by means of an ultrafine filter 4 and an ultrafilter 5, etc., and (B) the 2nd stage consisting in introducing 11 the cleaned growth soln. 24 into a growth vessel 12, in which a seed crystal 15 of the optical single crystal is disposed, subjecting the growth soln. to UV irradiation 19 and stirring 17, and growing the single crystal under the conditions of prohibiting the incorporation of the org. impurities into the grown crystal 16 while decomposing and removing the trace org. matter contained in the growth soln.
展开▼
