Hologram writing by the photorefractive effect

Abstract
A treatment, using numerical methods, is given for the time development of holograms in lithium niobate and similar materials. The special features of the treatment are that both the feedback effect of the space‐charge field on redistribution of electrons and the effect of the hologram in modifying the light pattern which is writing it are included, as is the effect of dark conductivity. The treatment is for uniform illumination of a crystal under constant applied voltage. The bulk photovoltaic effect is included through a ’’virtual field’’, an imaginary ’’built‐in’’ field acting on photoreleased electrons. The transport lengths are assumed to be short. It is shown that all the reported forms of time development are reproduced by the model.