We propose a theoretical model for the recently reported anomalously long decay of a space-charge field that was resonantly excited in a photorefractive sillenite crystal [Phys. Rev. Lett. 79, 67 (1997)]. The model is based on the conventional concept of charge transfer and does not require excessively large values of the quality factor for space-charge waves. The effect in question is qualified as a critical slowing of the relaxation process as the threshold of optical oscillation is approached.
© 1999 Optical Society of America
(090.7330) Holography : Volume gratings
(160.5320) Materials : Photorefractive materials
(190.4410) Nonlinear optics : Nonlinear optics, parametric processes
(190.5330) Nonlinear optics : Photorefractive optics
B. I. Sturman, E. V. Podivilov, H. C. Pedersen, and P. M. Johansen, "Critical slowing down of space-charge field relaxation in photorefractive sillenites," Opt. Lett. 24, 1163-1165 (1999)