The threshold effect of incident light intensity for the photorefractive light-induced scattering in LiNbO3:Fe,M (M=Mg2+, Zn2+, In3+) crystals

A study was conducted to investigate the origins of the threshold effect of the incident light intensity associated with the photorefractive light-induced scattering in LiNbO3:Fe,M crystals. Variations in the photovoltaic field were computed based on the conductivity and ratio of the incident light intensity. Results indicated that that the increased dark conductivity of the crystal is the origin of the threshold effect of incident light intensity.