Effect of DCTA on the Rapid Growth and Optical Characterization of KDP Crystal

Cyclohexanediaminetetraacetic acid(DCTA) as a new additive was added into the KDP growth solution.The KDP crystal was grown from aqueous solution with 100×10-6 DCTA by the point seed rapid growth technique,at growth rate of about 20 mm/d.Effects of the new additive DCTA on growth habit and optical quality of the rapidly grown KDP crystal were investigated and compared with those of EDTA which was a common additive used in the rapid growth of KDP crystal.With 100×10-6 DCTA added in growth solution,the metastable temperature zone width of solution increased about 10℃ and the growth rate of(100) faces of KDP crystal accelerated by 3–10 times.Furthermore,the optical quality of crystal doped with DCTA was improved significantly:such as 2–8 times rise of UV transmittance,great mitigation of light scattering and a few exaltation of laser damage threshold.Additionally,the beneficial effects of DCTA on growth habit and optical quality of the rapidly grown KDP crystal were more significant than those of EDTA with the same concentration.