Reconstruction characteristics of holographic data stored in a BSO crystal

Abstract

High data storage capacities and nearly instantaneous read-out of large amounts of data are the two most attractive features of using photorefractive crystals (PRC) in computing technology. The theoretical maximum storage capacity is in the order of 10¹⁵ bits in a 1 cm³ volume with a writing wavelength of 514.5 nm.
Bismuth silicon oxide (BSO), a drift-type photorefractive crystal, is of particular interest due to its fast writing time (ms regime). Numerous experiments have been performed regarding the holographic storage and retrieval of data in a photorefractive crystal. However, the reconstruction of the data relative to the originally stored information is still lacking from the literature. How much is retrieved from the stored information is still an unaddressed topic. In this paper, intensity patterns are recorded in a BSO crystal. Reconstructed patterns are then evaluated in terms of fidelity using Linfoot's criteria. Upon reconstruction, a simultaneous erasure of grating happens hence, the degradation of data fidelity under uniform illumination over time is also investigated.