OPTICAL-ABSORPTION AT 1.06 MU-M IN HIGHLY DEUTERATED POTASSIUM DIHYDROGEN PHOSPHATE

We have determined the relationship between residual proton (hydrogen) concentration and optical absorption at 1.06-mu-m in highly deuterated potassium dihydrogen phosphate (KDP). The proton concentration was determined by nuclear magnetic resonance (NMR) spectroscopy and the absorbance was measured by calorimetry. We obtained a hydrogen concentration dependence of 396 +/- 55 parts in 10(6) (ppm) cm-1/% hydrogen for the omicron- (ordinary-) polarized absorbance at 1.064-mu-m, and 45 +/- 7 ppm cm-1/% hydrogen for the e- (extraordinary) polarization. In addition, the KDP crystals we tested have residual (hydrogen-independent) omicron- and e-polarized absorbances of 958 +/- 228 ppm cm-1 and 343 +/- 28 ppm cm-1, respectively, whose origin is unknown. We also found that the crystal deuterium-hydrogen (D-H) ratio can be related to the D-H ratio of the growth solution by a simple ideal mixture model with a segregation coefficient of 0.684 +/- 0.044.