Identification data reproduction in multilayered optical waveguide-type holographic memory cards

The identification UD) data reproduction was computationally examined for the compatibility with the aperture multiplexing and the telecentric system. The mask for the multiplexing caused shade in the reproduced ID data cell. The shading tolerance was improved by modulating the phase of the original image so that the ID data holograms diffract the light in the oblique direction or with the concentrating. The telecentric system reproduced all ID data cells in the same position of the image sensor and made a distinction among the cells impossible. This was solved by reproducing the cell point symmetrically from the corresponding ID data hologram in each 3 x 3 ID data block. (C) 2008 Optical Society of America.