Abstract

Spatial solitons, which propagate without variation in their transverse intensiv profile, occur when nonlinear self-defocusing (focusing) exactly compensates the diffraction of dark (bright) amplitude profiles. Kerrlike media support spatial solitons,¹ typically requiring large powers (greater than watts and up to megawatts) and displaying widths that depend on intensity. Photorefractive media under the influence of an external electric field support two types of solitons. Quasi-steady-state, nonlocal photorefractive solitons occur in a transient (but long-lived) regime after the index perturbation forms but before background conductivity screens the external field²; they are intensity independent, permitting stable self-trapping in two dimensions. Photorefractive-screening solitons occur at steady state from nonuniform screening of an external electric field.^3,4

© 1995 Optical Society of America