Photorefractive recording of volume holograms in doped LiNbO3

Abstract

The principles of holographic recording in photorefractive LiNbO₃ are analysed and results of the basic equations are compared with experimental data for iron doped crystals. The asymmetry between writing and erasure sensitivity, the most important parameter for the recording of volume holograms, is explained in terms of the ratio of photovoltaic and conventional photocurrents. This ratio depends strongly on the impurity concentration. Crystals doped with suitable Fe concentration maximizing this ratio allow the multiple storage of more than 100 holograms.