Our experiment shows that stimulated backscattering from photorefractive LiNbO3:Fe crystals occurs not only for an orientation of the polar axis that is parallel to the input beam but also for the opposite orientation, in which the spatial amplification of seed scattering through π/2-shifted gratings is impossible. In the latter case scattering exhibits pronounced noise properties. We show analytically and numerically that the observed regularities are explained by a model including a source of low-frequency temporal noise for the space-charge field and a strong photovoltaic effect.
© 1996 Optical Society of America
S. G. Odoulov, B. I. Sturman, E. Shamonina, and K. H. Ringhofer, "Stochastic photorefractive backscattering from LiNbO3 crystals," Opt. Lett. 21, 854-856 (1996)