Abstract

Photoreactive gratings can be fixed if a complementary "grating" of some kind is created, which does not decay with time or under illumination. One promising mechanism is the fixing in ferroelectric photorefractive crystals through the formation of ferroelectric domains which electrically compensate the space-charge field. In other words, the direction of the spontaneous polarization P_s of the crystal can be selectively reversed such that the bound charge located on the domain walls electrically compensates the light-induced space-charge distribution of the original grating. This effect was observed first in the 70's in BaTiO₃¹ and SBN (Sr_xBa_1-xNb₂O₆).² Recently interest in this field has been revived and the research has been concentrated again on SBN^3-5 and BaTiO₃.^6-7

© 1995 Optical Society of America