TRANSMISSION OF A GAUSSIAN-BEAM THROUGH A NONLINEAR THIN-FILM NEAR THE TOTAL-REFLECTION STATE

We show by numerical simulation that a small-radius Gaussian beam impi nging upon a thin nonlinear film can switch from a total reflection st ate to a transmission state if the Kerr nonlinearity is positive. The phenomenon is nonresonant and is similar to interface switching. On th e other hand, great differences from previous plane-wave models appear . Extension of these results to wider beams seems possible according t o qualitative and quantitative arguments. For a negative nonlinearity the thin film acts as a Limiter of the transmitted intensity. For wide beams results are similar to plane-wave results.