Improvement of holographic data storage using optimized phase mask

Abstract

Holographic data storage has the advantages of high parallelism, fast access, and large capacity. The storage capacity is represented by the stored pages and pixels in each page. Due to the 3-D nature of the holographic medium, many pages of data may be multiplexed by various methods. For optimal use of the dynamic range of the medium, various phase masks are used to uniform the Fourier spectrum. The design of these masks is based on statistical properties of the input pixels. But, the interpixel cross talk, which is dominated by the pixels within the same page, is difficult to reduce owing to the diffraction of the limited aperture size of the medium. In the paper, we expect the spectrum to be uniform and the reconstruction error to be minimal simultaneously. Therefore, we set the targets of the spectral distribution to be constant /spl rho//sub f/ and the reconstructed amplitude /spl rho//sub 2/ equal to the input /spl rho//sub 1/. The desired /spl rho//sub f/ should be chosen so that the energy of the spectral plane would be equal to that of the input plane. We can get the transform matrix between input and Fourier plane and between input and output.