Improved Holographic Recording Techniques for Data-Page Rewriting

Novel holographic recording configurations capable of selective erasure of multiplexed holograms for data-page rewriting in holographic storage are presented. By using a half wave plate and a polarizing beam splitter as the phase control device of the interference pattern in holographic recording/erasure procedure, comparatively large-area and finespun data-pages may be recorded, selectively erased, and rewritten in simple operations. We experimentally demonstrate the selective erasure of multiplexed data-pages in photorefractive iron-doped LiNbO 3 crystals, and show the effectiveness of the configuration. We also propose a method to improve the in-plane uniformity of the erasure making use of the diffuser in the optical path of the object beam which is employed for dispersing the object image and the phase conjugate readout technique.