Properties of thermally fixed holograms in photorefractive LiNbO_3:Zn:Fe crystals

摘要

We have investigated the properties of thermally fixed holograms in LiNbO_3 crystals doped with the optical damage inhibitor Zn as well as the photorefractive Fe dopants. Time decays of fixed holograms at different temperatures showed a single thermally activated process with an activation energy of ～1.08 eV. We have also studied the effect of an external electric field on the diffraction efficiency of these holograms. Results analysis has provided a new method to determine the photovoltaic field of the samples as well as the effective concentration of photorefractive traps.