Dispersion of the Kerr constants of doped KCl crystals

The dispersion of the quadratic electro-optic (Kerr) constants of KCl crystals containing two substitutional impurities Pb2+ and Cu + has been determined. The constants (r11,11-R 11,22) and R12,12 are reported for the crystals at different concentrations of the impurities in the region 590-290 nm. The observed wavelength dependence is found to be similar to that of the piezo-optical constants of pure alkali halide crystals. The experimental data have been fitted to a simple Sellmeier relation and the dispersion constants are reported.