The growth temperature curve of the growth system for the potassium lithium
niobate (KLN) has been measured and the temperature decrease program has b
een calculated. KLN crystals with a size up to 30mm X 15mm X 5 mm have been
grown by flux method. The primary factors of the cracking of KLN crystal h
ave been discussed. A blue laser light output has been obtained by optical
parametric oscillator pumping.