Nonlinear refractive index of fluoride phosphate laser glasses

Summary form only given. When matter is exposed to intense electric fields polarization is no longer proportional to the electric field and the change in polarizability has to be extended by terms proportional to the square of the electric field. It follows for the refractive index: n=n/sub 0/+n~/sub 2/ /sup 2/=n/sub 0/+n/sub 2/I. Various methods exist to predict the nonlinear refractive index. One approach employs the d-line refractive index and the Abbe-number /spl nu//sub d/, which is defined as the inverse ratio of relative dispersion. Nonlinear refractive indices in fluoride phosphate glasses were determined by degenerate four-wave mixing relative to a reference sample.