Theoretical study of feedback-controlled photorefractive beam-coupling dynamics

Theoretically we investigate the operation of a novel nonlinear system, feedback controlled photorefractive beam coupling. It is shown that the feedback conditions used earlier ((pi) /2 phase shift between the diffracted and transmitted beam components) are satisfactory only during a relatively short initial stage of development. We have generalized these conditions by taking into account the inertia inherent any real feedback loop. The inertial feedback conditions ensure the permanent operation of the nonlinear system and lead to a variety of periodic and quasi-periodic regimes. We investigate the distinctive features of these regimes and transitions between them for moderately thick crystals.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.