Nonlinear optical interfaces: Switching behavior

We report the results of a study of the switching behavior of the interface between an ordinary dielectric and a nonlinear dielectric material with an intensity-dependent index of refraction. The non-linear dielectric used for these experiments consisted of a liquid suspension of dielectric particles. Because this medium has a very large effective nonlinearity, it was possible to perform these experiments with the CW output of an argon ion laser. Our experimental results are in excellent agreement with the predictions of numerical calculations based on a two-dimensional Gaussian input beam. We also report the observation of an unstable reflectivity state with a lifetime~ 10³times the response time of the nonlinear medium.