Threshold effect for photorefractive light-induced scattering and signal beam amplification in doped LiNbO3 crystals

In this article, we have studied experimentally the threshold effect of inc ident light intensity for the photorefractive light-induced scattering and signal beam amplification in doped LiNbO3 crystals. Our results show that t he signal beam can be most effectively amplified for a specific pump light intensity when the threshold effect of incident light intensity for photore fractive light-induced scattering is taken into account in doped LiNbO3 cry stals. Doping the LiNbO3 crystal with suitable concentration of Fe and dama ge-resistant dopants will provide an effective way to control the photorefr active properties of LiNbO3 crystal. We demonstrated the advantage of the f anning-noise-free double-doped photorefractive LiNbO3 crystals for three-di mensional storage. This method to suppress the fanning noise is very simple and convenient to practice. (C) 2000 American Institute of Physics. [S0021 -8979(00)01506-1].