25 October 1996 Characterization of a spatial and angular multiplexed volume holographic memory in terms of M/#
Author Affiliations +
Of the several configurations that have been proposed and studied for the implementation of a high-density, fast- access volume holographic memory system, a 90 degree(s) angular multiplexing configuration that uses a 45 degree(s)-cut iron- doped lithium niobate (LNB:Fe) crystal has attracted much attention in the last few years. In a recent paper, Burr and Psaltis have used this configuration to show that the diffraction efficiency ((eta) ) of each hologram can be estimated by (eta) equals (M/#/N)2, where N is the total number of angular-multiplexed holograms, and that the system parameter (M/#) can be determined by monitoring the recording and erasure dynamic of just one hologram. In addition, the authors have presented a mathematical expression which relates M/# to the photorefractive properties of the holographic material, the intensities of the recording beams and the recording geometry. We have applied the techniques (of Burr and Psaltis) to study a spatial and angular multiplexing configuration in the 90 degree(s) geometry. In this approach the angular multiplexing is combined with the spatial multiplexing technique by partitioning the crystal into a vertical array of `NL' layers, and each layer into a horizontal array of `NC' cells. If each cell can accommodate `N' holograms (by angular multiplexing, for example), then the total number of holograms recorded in the sample becomes N X NL X NC. In this paper, we present the theoretical and experimental results on cell-to-cell variation in M/# within a layer. Our results indicate that the cell-to-cell variation in the M/# can be reduced at the cost of a lower average M/# and a longer recording time. Advantages and limitations of both the theoretical model and the experimental techniques are discussed.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Arthur E. T. Chiou, Arthur E. T. Chiou, John H. Hong, John H. Hong, Ian C. McMichael, Ian C. McMichael, "Characterization of a spatial and angular multiplexed volume holographic memory in terms of M/#", Proc. SPIE 2849, Photorefractive Fiber and Crystal Devices: Materials, Optical Properties, and Applications II, (25 October 1996); doi: 10.1117/12.255475; https://doi.org/10.1117/12.255475

Back to Top