Abstract

Dynamics of the optical nonlinearities have previously been studied using time resolved four-wave mixing and inte1fero-metric techniques. Here, we show that the simple Z-scan technique¹ can be extended to obtain such dynamics in a nondegenerate excite-probe geometry. In this scheme, we obtain information regarding the sign, magnitude, lifetin1es, and dispersion of both absorptive and refractive components of optical nonlinearities. Nondegenerate two -photon absorption in ZnSe and cross-phase modulation in ZnS and ZnSe are measured and the results are shown to be in good agreement with the recent two-band model which utilizes the nonlinear Kramers-Kronig transformation to relate nonlinear absorption to nonlinear refraction.²

© 1992 Optical Society of America