Hologram recording medium, hologram recording-reproducing method, and horogram recording-reproducing apparatus

摘要

A hologram recording medium can record an interference pattern to a volume holographic memory at high density. Therefore, the hologram recording medium is made of a photo refractive crystal of a uniaxial crystal having a shape of parallel flat plates, and has a plurality of areas of a refractive index grating corresponding to one portion of a three-dimensional light interference pattern of a coherent signal light beam and coherent reference light of a first wavelength modulated in accordance with information data, wherein the areas of the refractive index grating respectively have a spatially independent columnar shape and are juxtaposed in parallel with each other, and lattice vectors of the refractive index grating in the adjacent areas of the refractive index grating exist in directions different from each other.