Abstract

Self-trapping of optical beams has been extensively studied during the last three decades. It occurs when the beam changes the optical properties of the medium it propagates in, giving rise to a strong optical non-linearity. Self-trapping of optical beams was observed in Kerr media, saturable nonlinear media, cascaded χ⁽²⁾ media, and photorefractives. However, all previous experimental observations and theoretical studies investigated self-trapping of spatially and temporally coherent light beams only. Here, we report the first observation of self-trapping of a "partially" spatially incoherent¹ and of a spatially and temporally incoherent (i.e., white light) optical beam in a nonlinear medium. Self-trapping occurs in both transverse dimensions, when diffraction is exactly balanced by photorefractive self-focusing. We have used the photorefractive nonlinearity associated with photorefractive solitons² as the self trapping mechanism. We show results of the self trapping of a white light beam and discuss recent advances in the understanding of this phenomena.

© 1997 Optical Society of America