The conditions for the existence and the main characteristics of weakly damped space-charge waves are investigated for photorefractive ferroelectrics. These conditions are opposite those derived previously for sillenites and may be fulfilled in such crystals as LiNbO<sub>3</sub>, BaTiO<sub>3</sub>, and SrBaNb<sub>2</sub>O<sub>6</sub>. The waves exist for sufficiently large values of the applied or photovoltaic field and have a linear dispersion law. The resonance excitation of space-charge waves by a moving light pattern is investigated. Possible manifestations of the instability of the photorefractive grating against parametric excitation of eigenmodes are considered.
© 1995 Optical Society of America
B. I. Sturman, E. Shamonina, M. Mann, and K. H. Ringhofer, "Space-charge waves in photorefractive ferroelectrics," J. Opt. Soc. Am. B 12, 1642-1650 (1995)