Abstract

Elementary holographic gratings are recorded in iron-doped near-stoichiometric lithium niobate crystals in the presence of an external electric field close to the coercive field. The resulting diffraction efficiency η vanishes upon subsequent homogeneous illumination but can temporarily be revealed by application of an external field well above the coercive field. All results are explained assuming that a ferroelectric domain pattern of only 0.01% modulation degree is created during recording. The process is similar to “electrical fixing” in other photorefractive materials.

© 2005 Optical Society of America