Experiment on hologram multiplexing with photorefractive beam-fanning speckle

We propose a hologram multiplexing method with the photorefractive beam-fanning speckle. In this method, a bulk photorefractive crystal takes the role of generating various speckle fields as well as storing a number of holograms. The hologram multiplexing and the selective retrieving are demonstrated with the speckled reference beam generated by the beam-fanning effect in a photorefractive BaTiO₃ crystal. The speckle field of the reference beam to record multiple holograms is varied by changing the spatial phase distribution or the intensity distribution of the original reference beam. We can successfully reconstruct the desired image from multiplexed holograms with the reference beam speckled by the beam-fanning effect in both procedures. This method has the potential for the all-optical control of the multiplexing and the selective retrieving from the multiplexed holograms, besides the simplification of the optical configuration comparing with the conventional speckle multiplexing.