Abstract

Storage capacity of volume holography is determined, among other factors, by the Bragg selectivity that can be achieved when multiplexing holographic images in a given physical space. Bragg mismatch is the primary consideration for evaluating the selectivity. However, in two main approaches to multiplexing—angular¹ and phase-code²—Bragg degeneracies can occur, further limiting the storage capacity. These limitations have been previously addressed in an optical neural network context, where the spectral extent of both reference and signal are confined to a small k-space region.³ We expand this treatment to the case of extended spectral band images that ate found in holographic storage. Furthermore, we show that when the reference beam occupies a large spectral region in k space, the Bragg degeneracies can be nonreciprocal and therefore pose a more severe problem.

© 1993 Optical Society of America