On the question of calculating the nonlinear refractive index of laser glasses

The equation for calculating the nonlinear refractive index, which is a complex dependence of the nonlinear refractive index on the refractive index and its dispersion coefficient, has been analyzed for a wide set of laser glasses. It is shown that the values obtained for the nonlinear refractive index differ by no more than 1% whether they are calculated from the refractive index in the green region and the corresponding dispersion coefficient or from the refractive index in the yellow region and the corresponding dispersion coefficient. Our analysis results in a substantially simpler mathematical expression that gives the same values of the nonlinear refractive index as the original equation. (C) 2015 Optical Society of America.