Optical Data Storage Using Persistent Spectral Hole Burning

The use of holography is attractive for optical data storage due to its poten­tial for implementing page oriented data storage systems. However, multiplexed recording using Bragg selective materials has not provided a large enough stor­age capability to justify the expense of these systems. Persistent spectral hole burning holography allows multiplexed recording using much smaller wavelength separations between the holograms, and hence dramatically increases the storage capacity possible in holographic memory systems [1]. A comparison between the wavelength selectivity obtained for transmission gratings recorded using hole burning in a dye doped polymer film versus Bragg selectivity in a 1 cm thick iron-doped lithium niobate crystal is shown in Fig. (1).