Nonlocal nonlinear refraction in Hibiscus sabdariffa with large phase shifts.

In this work we present a study of nonlinear optical properties in organic materials (hibiscus sabdariffa). Our results demonstrate that the medium exhibits a highly nonlocal nonlinear response. We show preliminary numerical results of the transmittance as nonlocal response by considering, simultaneously, the nonlinear absorption and refraction in media. Numerical results are accord to measurement obtained by Z- scan technique where we observe large phase shifts. We also analyze the far field diffraction ring patterns of the sample.

Dynamic of total internal reflection (2+1)D bright beams on photorefractive SBN61:Ce crystal.

We study experimentally and numerically the transient behavior of a (2+1)D beam when it is totally reflected by nonlinear interface formed by SBN61:Ce photorefractive crystal. The dynamics give rise to observation of new beams. Due to modulation instability of the beam, the nonlinear interface stimulates the break of the beam into new beams that are reflected to different angles.