Pseudorandom Codes for Volume Holographic Storage Application

The capacity of volume holographic storage depends largely on the number of holograms that can be multiplexed in a volume material and retrieved with minimum crosstalk and noise. There are different techniques under development for hologram multiplexing: spatial, angular, and wavelength multiplexing [1,2,3]. Spatial multiplexing is promising technology since it does not require any beam steering devices. The orthogonal codes were proposed as a solution to minimize hologram crosstalk noise [3]. It was found later that for minimum crosstalk noise, in addition to being orthogonal, the hologram address codes must be symmetric or antisymmetric around the midpoint [4]. In contrast to these investigations, instead of orthogonal codes, we propose to use pseudo random codes for volume holographic storage applications such as: hologram spatial multiplexing, key words for associative memory, and memory based on image holography.