Abstract

Photorefractive gratings can be fixed in ferroelectric crystals if a complimentary “grating" of ferroelectric domains is somehow created,^1-4 i.e., the direction of the spontaneous polarization P_s of the crystal is selectively reversed such that the bound charge located on the domain walls electrically compensates the light-induced space-charge distribution of the original grating. Usually the selective reversal of the direction of P_s is accomplished by first creating a space-charge distribution by the usual manner (interfacing two light beams in the crystal) and then applying an electric field in the direction opposite to P_s.

© 1994 IEEE