Steady-State Spatial Screening Solitons in Photorefractive Materials with External Applied Field

Steady-state dark (bright) planar spatial solitons are predicted for photorefractive materials when the diffraction of an optical beam is exactly compensated by nonlinear self-defocusing (focusing), due to the screening field set up around a dark notch (or a bright beam) in a photorefractive material to which an external field is applied. These screening solitons appear in steady state and differ from previously observed spatial solitons in their properties and physical origin.