The interaction of light with a nonlinear interface (NI), consisting of a linear dielectric material in contact with an intensity-dependent nonlinear material, exhibits a host of phenomena, including beam scanning and all-optical switching. Using a thermal negative nonlinearity, we studied the energy-dependent dynamics of beam switching from transmission to total internal reflection by a nonlinear sandwich (NS), which is essentially a double NI. We find that after a delay of a few ns, the transmitted beam explodes and subsequently implodes radially to the reflected beam. The radial symmetry is broken by the presence of the interface. This switching behavior is contrary to the prediction of the beam scanning from one spot to another across the NI.1,2 We also show that, by changing the incident energy or angle, the pulse duration of the reflected and transmitted beams can be varied.
© 1991 Optical Society of AmericaPDF Article