Self-conjugation of pump waves with 'boiling' speckle structure via backward stimulated diffusive scattering in an Fe:KNbO3crystal

We have investigated backward stimulated diffusive scattering of light with a time-varying speckle structure by photorefractive crystals in which the nonlinearity mechanism is diffusion-driven. We show that the efficiency and conjugated fraction for this process depend on the ratio of the coherence time to the dielectric relaxation time of the medium.