Feature

Dark Incoherent Solitons

Zhigang Chen, San Francisco State Univ., San Francisco, CA; Matthew Mitchell and Mordechai Segev, Princeton Univ., Princeton, NJ; Tamer H. Coskun and Demetrios N. Christodoulides, Lehigh Univ., Bethlehem, PA.

Dark beams are nonuniform optical beams that contain either a 1-D dark stripe or a 2-D dark hole resulting from a phase singularity or an amplitude depression in their optical field. Thus far, self-trapped dark beams (dark solitons) have been observed using coherent light only. Recently, however, we have demonstrated self-trapping of dark incoherent light beams (or, in a broader prospective, self-trapping of dark incoherent wave-packets in nature) for the first time. Both dark stripes and holes (vortices) nested in a broad partially spatially incoherent wavefront were shown to self-trap and form incoherent dark solitons in a nonlinear photorefractive crystal. These self-trapped 1-D and 2-D dark beams induce refractive-index changes akin to planar and circular dielectric waveguides, which introduces the possibility of controlling high-power laser light with low-power incoherent optical sources such as LEDs.