Nonlinear Bloch-wave interaction and Bragg scattering in optically induced lattices

The light propagation in optically induced photonic lattices near the bragg scattering angle was analyzed. The nonlinear Bloch-wave interaction and self-focusing in the spectrum gaps were also determined. The key patterns of the beam scattering and the self action were observed by the generic relation established between the Bloch-wave spectrum and the structure of diffracted waves. It was found that the bragg scattering of light reveal the key physical mechanisms which govern the nonlinear self-action of narrow beams under the combined effects of bragg scattering and wave diffraction.