Cross talk in phase-coded holographic memories
The cross talk between holograms multiplexed with Walsh-Hadamard phase codes is analyzed. Each hologram is stored with a reference beam that consists of N phase-coded plane waves. The signal-to-noise ratio (SNR) is calculated for a recording schedule for which the center of each stored image coincides with the nulls of the selectivity function for the adjacent plane-wave components of the reference beam. The SNR characteristics for phase coding with Walsh-Hadamard phase codes are then compared with the SNR for angle and wavelength multiplexing.