Method and apparatus for recording hologram, method and apparatus for reproducing hologram, and information retaining body

摘要

While Fourier transformation of a signal light beam is performed to perform recording during holographic recording so that a focal point is formed outside a holographic recording layer (defocus recording), an aperture is arranged on an outgoing side of the reproduced signal light beam (reproduction light beam), the reproduction light beam is focused at the aperture, and low-order components of a Fourier transform image of the reproduction light beam are selectively transmitted to detect only the transmitted light beam. Therefore, information recorded as the hologram in the holographic recording layer can be reproduced with high S/N ratio from the holographic recording layer added onto a support body, particularly onto a sheet member having non-optical quality such as paper and a plastic card.