摘要:
A multilayer holographic recording medium that improves recording density and data transfer rates. The multilayer holographic recording medium, from which information is reproduced by a multilayer holographic memory reproducing apparatus, includes a plurality of deposited holographic recording layers. During recording, a reference beam is common to those holographic recording layers and an incident angle of an object beam is modulated for each holographic recording layer. During reproduction, a laser beam for reproduction having the same condition as that of the reference beam used for recording is projected thereonto, so that diffraction beams are simultaneously generated in the respective holographic recording layers to directions that are the same as incident directions of the object beam used for recording.
摘要:
A holographic recording medium 10 is configured to have a recording layer 12 on which information can be recorded as holograms; and first and second heat generating layers 14A and 14B provided in a pair so as to sandwich the recording layer 12. Then, the first and second heat generating layers 14A and 14B are allowed to generate heat by being irradiated with a heat generating laser beam LB3 having a wavelength that is different from that of a signal beam LB1 or a reference beam LB2 for reproducing or recording information. The holographic recording medium and a method for recording and reproducing the same, and a recording and reproducing apparatus can compensate for shrinkage of the recording layer due to recording or variations in temperature, thereby allowing for reproduction of the holograms under optimum conditions.
摘要:
A white-light reconstruction hologram and a Fourier hologram for data can be recorded in a same holographic recording medium. The holographic recording medium includes, in a substantially identical plane, a white-light reconstruction holographic recording layer region capable of forming a white-light reconstruction hologram, having a thickness of 2 μm to 80 μm, and a Fourier holographic recording layer region capable of multiplexed hologram recording, having a thickness of 100 μm to 2 cm.
摘要:
A holographic multiplex recording method is provided in which remaining dynamic range in each recording area is made more uniform upon holographic multiplex recording. In this holographic recording method, a first-stage recording spot row RX1 is formed by arranging recording spots RS in an X-axis direction without overlapping, and then a second-stage recording spot row RX2 formed of the recording spots RS without overlapping in the X-axis direction is recorded in a position for shift multiplex recording in a Y-axis direction. This is repeated to form a Y-axis direction first multiplex recording spot matrix TYX1. In this case, recording is performed to all recordable regions without shift multiplex recording in the X-axis direction. Subsequently, a Y-axis direction second multiplex recording spot matrix TYX2 is formed in a position shift-multiplexed in the X-axis direction with respect to the first-stage recording spot row RX1 initially recorded. The shift multiplex recording in the X-axis direction is performed in a similar manner up to a Y-axis direction last multiplex recording spot matrix TYXn to thereby complete the recording.
摘要:
A holographic recording medium 10 includes: a recording layer 12; two substrates 14 and 16 sandwiching the same; and a photosensitive protective layer 18 covering these recording layer 12 and substrates 14 and 16 entirely. The recording layer 12 is set so that its photosensitivity corresponding to a recording wavelength falls in the vicinity of the recording wavelength from shorter wavelengths to longer wavelengths. The photosensitive protective layer 18 is set so that its light transmittance corresponding to the recording wavelength falls in the vicinity of the recording wavelength from longer wavelengths to shorter wavelengths. This improves damage of the recording layer from ambient exposure without a drop in recording sensitivity.
摘要:
A holographic recording method and a holographic recording apparatus which can provide a shortened time for recording and an improved data rate during recording even when the recording material has a low photosensitivity or the light source has a low power. This is achieved by, before a minimum exposure time for forming a reproducible hologram is reached, completing an interference exposure using signal light and reference light to form an incomplete hologram; performing an independent exposure for irradiating the incomplete hologram with the reference light after the interference exposure to thereby produce diffracted light; and recording information by means of interference between the reference light and the diffracted light.
摘要:
A holographic recording medium 10 includes: a recording layer 12; two substrates 14 and 16 sandwiching the same; and a photosensitive protective layer 18 covering these recording layer 12 and substrates 14 and 16 entirely. The recording layer 12 is set so that its photosensitivity corresponding to a recording wavelength falls in the vicinity of the recording wavelength from shorter wavelengths to longer wavelengths. The photosensitive protective layer 18 is set so that its light transmittance corresponding to the recording wavelength falls in the vicinity of the recording wavelength from longer wavelengths to shorter wavelengths. This improves damage of the recording layer from ambient exposure without a drop in recording sensitivity.
摘要:
A holographic multiplex recording method is provided in which remaining dynamic range in each recording area is made more uniform upon holographic multiplex recording. In this holographic recording method, a first-stage recording spot row RX1 is formed by arranging recording spots RS in an X-axis direction without overlapping, and then a second-stage recording spot row RX2 formed of the recording spots RS without overlapping in the X-axis direction is recorded in a position for shift multiplex recording in a Y-axis direction. This is repeated to form a Y-axis direction first multiplex recording spot matrix TYX1. In this case, recording is performed to all recordable regions without shift multiplex recording in the X-axis direction. Subsequently, a Y-axis direction second multiplex recording spot matrix TYX2 is formed in a position shift-multiplexed in the X-axis direction with respect to the first-stage recording spot row RX1 initially recorded. The shift multiplex recording in the X-axis direction is performed in a similar manner up to a Y-axis direction last multiplex recording spot matrix TYXn to thereby complete the recording.
摘要:
The pitch of light beam spots on a light receiving surface of an address detector upon search of information recorded on a holographic recording medium is decreased to reduce a distance between the holographic recording medium and the address detector. In a holographic recording and reproducing apparatus 10, a reference beam having an elliptical beam shape transformed by a beam shaping optical system 30 and an object beam having an unchanged circular shape are projected onto a holographic recording medium 20 so that interference fringes are allowed to be formed only within the elliptical shape. Therefore, even when the distance of an address detector 28 from the holographic recording medium 20 is reduced, crosstalk is prevented between array-shaped two-dimensional photodetectors 28A, 28B, 28C, and so on constituting the address detector 28.
摘要:
A holographic recording medium which has parallelism of high precision and causes little substrate deformation ascribable to contraction of its recording areas when recording interference fringes, and a method for manufacturing the same. The holographic recording medium 10 has a holographic recording material layer 18 between a first transparent substrate 12 and a second transparent substrate 14. This holographic recording material layer 18 is formed integrally with a spacer 16 which is composed of a large number of spherical beads 16A arranged so as to surround recording areas 20 for interference fringes to be recorded on.