THE THRESHOLD EFFECT OF INCIDENT LIGHT-INTENSITY FOR THE PHOTOREFRACTIVE LIGHT-INDUCED SCATTERING IN LINBO3-FE,M (M = MG2+, ZN2+, IN3+) CRYSTALS

Based on the two-center model and the multi-three-wave mixing model, w e theoretically study the possible origins of the threshold effect of the incident light intensity for the photorefractive light-induced sca ttering in LiNbO3:Fe,M, (M=Mg2+, Zn2+, In3+) crystals. Our results sho w that the value of the threshold intensity of incident light is stron gly dependent on the dark conductivity of the crystal, and the maximum total fanning noise is dependent on the concentration of Fe ion on th e Li site. These two factors together determine the threshold behavior of incident light intensity for the photorefractive light-induced sca ttering in LiNbO3:Fe,M crystals when the incident light intensity is i n moderate range. (C) 1998 American Institute of Physics.