Abstract: A holographic device includes a reference beam unit that makes reference beams incident on a plurality of holograms formed in a plate-shaped recording medium; and a light receiving unit that receives exiting light from the holograms. The reference beam unit includes a light emitting part that emits the reference beams, and sets the incidence position and the incidence angle of each of the reference beams emitted from the light emitting part such that each of the reference beams is incident on one of the plurality of holograms disposed in the thicknesswise direction of the recording medium. The light receiving unit includes a light receiving part that receives the exiting light from the holograms and a pin-hole filter disposed between the light receiving part and the recording medium.

Abstract: A hologram device reproduces information from a recording medium having holograms thereon by irradiating light beams emitted from a light source thereon. The light source is composed of a substrate and a plurality of light emitting units arranged on the substrate. A condensing unit is provided between the light source and the recording medium to condense a plurality of light beams emitted from the plurality of light emitting units onto approximately the same location of the recording medium.

Abstract: The present invention provides a polarization separating element which can be easily manufactured without increasing the cost and can separate light into plural directions by using one sheet. A polarization separating element includes a structural birefringence body having a base body made of a photosensitive material of which periodic refractive index distributions are formed in plural directions and at least a pair of surfaces is formed in the base body in which one surface is a light incident location and the other surface is a light emitting location.

Abstract: A holographic memory device includes a laser oscillator for emitting multimode laser light to be incident on a holographic storage medium. The laser light of a main mode has a half-width such that the wavelength distribution of the main mode is continuous with the wavelength distributions of the two adjacent side modes and such that the laser light has a continuous wavelength distribution over the main mode and all the side modes.

Abstract: A wavelength-tunable light source includes an emitting section that emits light having a plurality of single wavelengths on a substrate. Surface-emitting lasers are arranged in close proximity to each other on the substrate in the emitting section. The number of surface-emitting lasers corresponds to the number of wavelengths to be emitted. The light with the wavelengths emitted from the respective surface-emitting lasers is incident on a medium at substantially the same position.