In photo refractive polymers, refractive index modulation (1,2) is induced by the space-charge field that results from the redistribution of positive and negative charge carriers induced by light excitement. More charge separation occurs where light is more intense. A hologram is made superimposing a second wavefront (reference beam, green in figure) on the wavefront of interest generating an interference pattern (orange in figure) that is record on physical medium ca. PVK film (2D image). Then, the second wavefront illuminates the interference pattern that is diffracted (blue in figure) to recreate the original wavefront (static 3D images)
Dynamic holograph image (3) can be obtained using simultaneously a third beam (probe, not shown). The updatable holograph can be recorded in a photorefractive polymeric composites (PPC)(PVK mixture) using the two coherent laser beams (object and reference beams) and then read out by a probe beam to reconstruct the dynamic holographic image.
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