crystal was about 40rpm. From temperature was decreased at 0.1 oClday at the beginning of the growth. As the growth progressed the temperature lowering rate was increased. After reaching the room temperature, an optically transparent KDP single crystal of size 45 x 25 x 15 mm3 was obtained. The grown crystal is shown in Fig. 2. For various techniques, pure and K2CO3 doped characterization concentrations viz., 1,5 and 10 M%) KDP crystals were (in different grown by the slow cooling method with stirring under identical conditions.