NONDEGENERATE OPTICAL KERR-EFFECT IN SEMICONDUCTORS

We calculate the nondegenerate bound electronic nonlinear refractive i ndex n2(omega1; omega2) (i.e., an index change at frequency omega1 due to the presence of a beam at frequency omega2) in semiconductors. We calculate this nonlinearity and its dispersion using a Kramers-Kronig transformation on the calculated nondegenerate nonlinear absorption sp ectrum due to two-photon absorption, electronic Raman and optical Star k effects. The calculated n2 values and their dispersion are compared to new experimental values for ZnSe and ZnS obtained using a 2-color Z -scan.