Investigation of the influence of the optical quality of KDP crystals on the efficiency of conversion in second harmonic generation

The conventional inhomogeneity coefficient of a crystal and two parameters associated with second harmonic generation ("power" parameter κ and half-width of the spatial distribution of the second harmonic intensity) were determined for three KDP crystals of different optical quality. It was found that the power parameter could be used, in some respect, as a measure of the optical quality of nonlinear KDP crystals, whereas the second parameter (half-width) showed no significant correlation with quality.