Abstract

Incoherently coupled photorefractive spatial soliton pairs are observed in a biased photorefractive SBN crystal, as has been predicted recently.¹ These soliton pairs involve two steady- state screening solitons² that propagate collinearly in the crystal and experience a refractive-index modulation induced by both beams. Thus they differ in their physical origin from soliton paring in Kerr-type nonlinear systems.³ A coupled photorefractive soliton pair can have dark-bright as well as bright- bright and dark-dark realizations. In all of these cases, once a soliton pair is decoupled (i.e., one beam is blocked), the remaining component alone cannot “survive” as a soliton under the same experimental condition. We observe the coupling-decoupling dynamics between two photorefractive screening solitons.

© 1997 Optical Society of America