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WO2007102570A1 - enregistreur d'informations et reproducteur d'informations - Google Patents

enregistreur d'informations et reproducteur d'informations Download PDF

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Publication number
WO2007102570A1
WO2007102570A1 PCT/JP2007/054511 JP2007054511W WO2007102570A1 WO 2007102570 A1 WO2007102570 A1 WO 2007102570A1 JP 2007054511 W JP2007054511 W JP 2007054511W WO 2007102570 A1 WO2007102570 A1 WO 2007102570A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
hologram recording
recording medium
axis
information
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2007/054511
Other languages
English (en)
Japanese (ja)
Inventor
Masaki Tanaka
Tetsuo Saeki
Kuniaki Okada
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sharp Corp
Original Assignee
Sharp Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sharp Corp filed Critical Sharp Corp
Publication of WO2007102570A1 publication Critical patent/WO2007102570A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/0065—Recording, reproducing or erasing by using optical interference patterns, e.g. holograms
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1395—Beam splitters or combiners
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/26—Processes or apparatus specially adapted to produce multiple sub- holograms or to obtain images from them, e.g. multicolour technique
    • G03H1/2645—Multiplexing processes, e.g. aperture, shift, or wavefront multiplexing
    • G03H1/265—Angle multiplexing; Multichannel holograms

Definitions

  • the present invention relates to an information recording apparatus and an information reproducing apparatus, and more particularly to an information recording apparatus for recording information on a holographic recording medium and an information reproducing apparatus for reproducing information.
  • hologram recording in which information is recorded on a recording medium using holography, signal light having image information is superimposed on a reference light inside the hologram recording medium, and interference fringes that can be formed at that time.
  • the hologram recording medium is irradiated with the reference light, whereby the image information is reproduced by the diffraction at the interference fringes.
  • a reproduction signal is obtained by image processing the reproduced image information.
  • Interference fringes are three-dimensionally written in a hologram recording medium to increase the storage capacity of the hologram recording medium using multiple recording.
  • multiplexing systems for hologram recording such as angle multiplexing, space shift multiplexing, Peristo-Port-Fick multiplexing, and combinations of these multiplexing systems have also been proposed.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 10-124782
  • a signal light beam is disposed at the center of the pupil plane of the objective lens, and two reference light beams are disposed at the outer edge so as to sandwich the signal light. These three light fluxes are condensed on the hologram recording medium by the objective lens and interfered to write interference fringes.
  • a spherical wave is used as the reference light. Therefore, when the convergence point is shifted in the in-plane direction, another information light interference pattern can be recorded, and multiple recording can be performed.
  • Non-Patent Document 1 (Aprilis Drive, US Aprils, Internet ⁇ URL: http://www.aprilisinc.com/aprilis-drive, htm>) is a light ice ⁇ *
  • An operation example of a hologram recording and reproducing apparatus for recording and reproducing information is shown.
  • This holo In the recording / reproducing apparatus, in the writing mode, image information is encoded into digital data and written on a rotating optical disc at a rate of 1 Gbit Z seconds. In the read mode, the optical disk is irradiated with the reference light to reproduce the image information written on the optical disk on the detector.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 10-124782
  • Non Patent Literature 1 Apris Drive (Aprilis Drive), US Apris, Internet ⁇ URL: http://www.aprilisinc.com/aprilis_dnve.htm>
  • Non-Patent Document 1 since the hologram recording area in which the reference light and the signal light overlap in the hologram recording medium is axially symmetrical with respect to the optical axis of the signal light, The amount of crosstalk is constant. However, in the hologram recording and reproducing apparatus, since the position and the angle of the reference light are fixed, there is a problem that the multiplicity of hologram recording can not be increased.
  • an object of the present invention is to provide an information recording apparatus and an information reproducing apparatus capable of increasing the degree of hologram recording while maintaining the amount of crosstalk constant.
  • an information recording apparatus for shift-multiplex-recording information on a hologram recording medium, which divides light emitted from a light source into signal light and a plurality of reference lights.
  • a light flux control element for controlling the position and area size of the signal light and Z or the reference light, and a focusing optical system for guiding the signal light and the reference light to the same area of the hologram recording medium.
  • the luminous flux control element provides an even number of reference beams around the signal light on the pupil plane of the focusing optical system, and arranges the even number of reference beams so as to be rotationally symmetric about the optical axis of the signal beam.
  • the luminous flux control element is configured such that even reference beams are not in line symmetry with respect to a first axis used for shift multiplexing and a second axis orthogonal to the first axis. Place on
  • the optical axis of the signal light passes through the intersection of the first axis and the second axis. Control to do so.
  • the hologram recording medium is a rotating disk type, and the first axis corresponds to the tangential direction of the hologram recording medium, and the second axis corresponds to the radial direction of the hologram recording medium.
  • the hologram recording medium is a rectangular card type, and the first axis corresponds to the direction of one side of the hologram recording medium, and the second axis is the direction of the other side of the hologram recording medium.
  • the first axis corresponds to the direction of one side of the hologram recording medium, and the second axis is the direction of the other side of the hologram recording medium.
  • the light flux control element controls so that the optical axis of the signal light substantially coincides with the optical axis of the focusing optical system.
  • an information reproducing apparatus for reproducing information recorded on a hologram recording medium, which divides light emitted from a light source into signal light and a plurality of reference lights. And a light flux control element for controlling the position and area size of the signal light and Z or the reference light, and a focusing optical system for guiding the signal light and the reference light to the same area of the hologram recording medium.
  • the luminous flux control element provides an even number of reference beams around the signal light on the pupil plane of the condensing optical system, and arranges the even number of reference beams so as to be rotationally symmetric about the optical axis of the signal beam.
  • FIG. 1 is a cross-sectional view showing a schematic configuration of a hologram recording and reproducing apparatus 1000 as a background for explaining an embodiment of the present invention.
  • FIG. 2 is a diagram showing a change in diffraction efficiency when the hologram recording medium 57 is moved in the X direction.
  • FIG. 3 is a cross-sectional view showing a schematic configuration of a hologram recording and reproducing apparatus 100 according to Embodiment 1 of the present invention.
  • FIG. 4 is a view showing an example of the arrangement of the signal light 12 and the reference lights 13a to 13d on the objective lens 6 at the time of recording.
  • FIG. 5 is a view showing a change in diffraction efficiency when the hologram recording medium 7 is moved in the X direction.
  • FIG. 6 is a view showing another example of the arrangement of the signal light 12 and the reference lights 13a to 13d on the objective lens 6 at the time of recording.
  • FIG. 1 is a cross-sectional view showing a schematic configuration of a hologram recording and reproducing apparatus 1000 as a background for explaining the embodiment of the present invention.
  • the hologram recording / reproducing device is a device having the functions of the hologram recording device (information recording device) and the hologram reproducing device (information reproducing device), but the hologram recording device and the hologram reproducing device are separately provided. It is of course also possible to configure. That is, the hologram recording and reproducing apparatus 1000 may be replaced with the hologram recording apparatus 1000A and the hologram reproducing apparatus 1000B. This is the same as in the first embodiment described later.
  • the hologram recording / reproducing apparatus 1000 includes a laser 51, a collimator lens 52, a spatial light amplitude modulator 53, a polarization beam splitter 54, a 1Z4 wavelength plate 55, and an objective lens 56. And an imaging device 58.
  • the hologram recording and reproducing apparatus 1000 records information on the hologram recording medium 57 having the reflection film 59 and reproduces the information from the hologram recording medium 57.
  • the hologram recording and reproducing apparatus 1000 records and reproduces information by a combination of the space shift multiplexing method and the peristaltic multiplexing method.
  • the operation at the time of recording of the hologram recording and reproducing apparatus 1000 will be described.
  • the laser beam 61 emitted from the laser 51 is converted into parallel light by the collimator lens 52, and the spatial light It is led to the width modulator 53.
  • the spatial light amplitude modulator 53 divides the incident laser light 61 into the signal light 62 and the reference light 63, and amplitude modulates as needed in each region. Thereafter, the signal light 62 and the reference light 63 follow the path 64 and are condensed into the hologram recording medium 57 by the objective lens 56.
  • the collected signal light 62 and reference light 63 interfere within the hologram recording medium 57, and the interference fringes are recorded on the hologram recording medium 57.
  • the spatial light amplitude modulator 53 generates only the reference light 63 from the incident laser light 61.
  • the generated reference light 63 is condensed by the objective lens 56 to a hologram in the hologram recording medium 57.
  • the collected reference beam 63 is diffracted by the holographic fringes of the hologram recorded in the hologram recording medium 57 to generate a reproduced beam 66 according to the recorded information.
  • the reproduction light 66 is guided along the path 65 to the imaging device 58.
  • the imaging device 58 detects the intensity distribution pattern of the reproduction light 66.
  • a reproduction signal of the hologram recording medium 57 is generated.
  • the hologram recording / reproduction apparatus 1000 of FIG. 1 realizes perist aperture physical multiplexing by changing the position of the reference light 63 along the outer edge of the objective lens 56 under spatial shift multiplexing. To increase the recording density.
  • the hologram recording / reproduction apparatus 1000 performs recording by causing the signal light 62 to interfere with each other in the holographic recording medium 57 using one reference light 63. Therefore, as shown in FIG. 1, in the hologram recording and reproducing apparatus 1000, in the hologram recording medium 57, the hologram recording area in which the information beam 62 and the reference beam 63 overlap is asymmetric.
  • FIG. 2 is a diagram showing a change in diffraction efficiency when the hologram recording medium 57 is moved in the X direction.
  • FIG. 2 shows a change in diffraction efficiency of the reference light 63 when the hologram recording medium 57 is moved in the X direction (see FIG. 1) while irradiating only the reference light 63 to the hologram recording medium 57 at the time of reproduction.
  • the diffraction efficiency is The way of change is different. Specifically, the distance (hereinafter referred to as the Bragg null width) to the position (hereinafter referred to as the Bragg null point) at which the diffraction efficiency is maximized at the position force 0 is , + + X direction and asymmetry in one X direction.
  • FIG. 3 is a cross-sectional view showing a schematic configuration of the hologram recording and reproduction apparatus 100 according to the first embodiment of the present invention.
  • the hologram recording / reproducing apparatus 100 includes a laser 1, a collimator lens 2, a spatial light amplitude modulator 3, a polarization beam splitter 4, a 1Z4 wavelength plate 5, an objective lens 6, and an imaging device.
  • the hologram recording and reproducing apparatus 100 records information on the hologram recording medium 7 having the reflection film 9 and reproduces information on the hologram recording medium 7.
  • the hologram recording medium 7 is, for example, a rotating optical disk type or a card type.
  • the operation at the time of recording of the hologram recording / reproducing apparatus 100 will be described.
  • the laser light 11 emitted from the laser 1 is converted into parallel light by the collimator lens 2 and is guided to the spatial light amplitude modulator 3.
  • the spatial light amplitude modulator 3 divides the incident laser light 11 into the signal light 12 and the reference lights 13a to 13d (13b and 13d are not shown in FIG. 3) of the four light fluxes, and is necessary in each region. Modulate the amplitude accordingly.
  • the amplitude modulation pattern of the signal light 12 is generated based on the data recorded on the hologram recording medium 7.
  • the reference beams 13a to 13d may be light having a uniform intensity distribution or light having undergone amplitude modulation.
  • the spatial light amplitude modulator 3 is an example of a light flux control element, and may be a movable mask or an optical shutter.
  • FIG. 4 is a view showing an example of the arrangement of the signal light 12 and the reference lights 13a to 13d on the objective lens 6 at the time of recording.
  • the hologram recording and reproducing apparatus 100 shifts the hologram recording medium 7 in the X and Y directions (see FIG. 3) to perform space shift multiplexing, the positions of the respective light beams of the signal light 12 and the reference lights 13a to 13d are
  • the pupil plane of the lens 6 can be arranged as shown in FIG. Referring to FIG. 4, each luminous flux of reference beams 13a to 13d at the time of recording is arranged, for example, so as to be rotationally symmetric about the optical axis of objective lens 6, and for the X axis and the Y axis. It is arranged as if it is line-symmetrical.
  • the signal light 12 and the reference lights 13 a to 13 d travel along the path 14, pass through the polarizing beam splitter 4, and are converted into circularly polarized light by the 1Z4 wavelength plate 5.
  • the signal light 12 and the reference lights 13 a to 13 d converted into circularly polarized light are condensed into the hologram recording medium 7 by the objective lens 6.
  • the focused signal light 12 and the reference lights 13 a to 13 d interfere in the hologram recording medium 7, and the interference fringes are recorded on the hologram recording medium 7.
  • the hologram recording medium 7 has a reflection film 9 on the surface opposite to the surface on which the signal light 12 and the reference lights 13a to 13d are incident.
  • the spatial light amplitude modulator 3 generates only the reference lights 13a to 13d from the incident laser light 11 and does not generate the signal light 12.
  • the generated linearly polarized reference beams 13 a to 13 d pass through the polarization beam splitter 4 and are converted into circularly polarized light by the 1Z4 wavelength plate 5.
  • the reference lights 13 a to 13 d converted into circularly polarized light are condensed by the objective lens 56 into the recorded hologram in the hologram recording medium 7.
  • the collected reference beams 13a to 13d are diffracted by the interference fringes of the hologram recorded in the hologram recording medium 7 to generate the reproduction beam 16 according to the recorded information.
  • the reproduction light 16 passes through the objective lens 6, follows the path 15, and is converted by the 1Z4 wave plate 5 into circularly polarized light linearly polarized light.
  • the reproduction light 16 converted into the linearly polarized light is reflected by the polarization beam splitter 4 and is guided to the imaging device 8.
  • the imaging element 8 detects the intensity distribution pattern of the reproduction light 16. A reproduction signal of the hologram recording medium 7 is generated from this detected image.
  • FIG. 5 is a diagram showing a change in diffraction efficiency when the hologram recording medium 7 is moved in the X direction.
  • FIG. 5 shows a change in diffraction efficiency of the reference light 13 when the hologram recording medium 7 is moved in the X direction (see FIG. 3) while irradiating only the reference light 13 to the hologram recording medium 7 at the time of reproduction.
  • the interference area in the hologram recording medium 7 is substantially line symmetrical with respect to the optical axis of the signal light 12. Because of this In the program recording / reproducing apparatus 100, the Bragg null width XO-XI when moving the hologram recording medium 7 in the + X direction is equal to the Bragg null width XO-X2 when moving the hologram recording medium 7 in the X direction. Become.
  • the hologram recording and reproducing apparatus 100 it is desirable to write a hologram at a position adjacent to the Bragg null point in order to reduce crosstalk.
  • the Bragg null width By making the Bragg null width constant, crosstalk can be reduced over the entire area of the hologram recording medium 7.
  • the black null width in the Y direction can be made constant as in the X direction. This can reduce crosstalk.
  • FIG. 6 is a view showing another example of the arrangement of the signal light 12 and the reference lights 13a to 13d on the objective lens 6 at the time of recording.
  • the hologram recording and reproducing apparatus 100 shifts the hologram recording medium 7 in the X and Y directions (see FIG. 3) to perform space shift multiplexing, the positions of the respective light beams of the signal light 12 and the reference lights 13a to 13d are
  • the pupil plane of the objective lens 6 can be arranged as shown in FIG.
  • respective luminous fluxes of reference beams 13a to 13d at the time of recording are arranged so as to be rotationally symmetric at the center of the optical axis of objective lens 6 at different positions from FIG. It is arranged so as not to be line symmetrical about Y axis and Y axis.
  • the Bragg null width does not change.
  • the hologram recording / reproduction apparatus 100 can perform multiplex recording by changing the arrangement of the light beams of the reference beams 13a to 13d, as well as space shift multiplexing. As described above, by increasing the multiplicity, it is possible to increase the recording density more than in the case of space shift multiplexing alone.
  • the shape of the hologram recording medium 7 is not particularly limited.
  • the hologram recording medium 7 is a rotating disk type
  • recording and reproducing information can be efficiently performed by setting the X direction as the tangential direction and the Y direction as the radial direction.
  • the hologram recording medium 7 is a card type
  • information can be efficiently recorded and reproduced by setting the direction parallel to each side of the card as the X direction and the Y direction.
  • the hologram recording / reproduction device has the objective lens pupil plane.
  • the black null width of the hologram recording medium is fixed by providing even number reference light beams around the signal light and arranging the even reference light beams to be rotationally symmetric about the optical axis of the signal light. And In this way, recording can be performed with a constant shift pitch during space shift multiplexing.
  • the Bragg null width in the radial direction and tangent direction is made constant.
  • recording can be performed with a constant shift pitch during space shift multiplexing in either the radial direction or tangential direction.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Holo Graphy (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Optical Head (AREA)

Abstract

L'invention concerne un enregistreur / reproducteur d'hologrammes (100), dans lequel un nombre pair de flux lumineux incluant des faisceaux de référence (13a, 13b) est disposé autour d'un faisceau de signal (12) dans le plan pupille de la lentille d'un objectif (6). Les flux lumineux des faisceaux de référence sont disposés par rotation symétriquement par rapport à l'axe optique du signal (12) de telle sorte qu'un support d'enregistrement holographique (7) a une largeur de Bragg constamment nulle. En conséquence, on peut effectuer un enregistrement tout en maintenant un pas à décalage constant au cours du multiplexage spatial du décalage.
PCT/JP2007/054511 2006-03-09 2007-03-08 enregistreur d'informations et reproducteur d'informations Ceased WO2007102570A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2006063588A JP2007242145A (ja) 2006-03-09 2006-03-09 情報記録装置および情報再生装置
JP2006-063588 2006-03-09

Publications (1)

Publication Number Publication Date
WO2007102570A1 true WO2007102570A1 (fr) 2007-09-13

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PCT/JP2007/054511 Ceased WO2007102570A1 (fr) 2006-03-09 2007-03-08 enregistreur d'informations et reproducteur d'informations

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WO (1) WO2007102570A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8031383B2 (en) * 2007-10-23 2011-10-04 Thomson Licensing Common aperture holographic storage system with reduced noise

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000098863A (ja) * 1998-09-24 2000-04-07 Fuji Xerox Co Ltd 光記録方法および光記録装置
JP2004361928A (ja) * 2003-05-13 2004-12-24 Optware:Kk 光情報記録方法、光情報記録装置および光情報記録再生装置
JP2005293630A (ja) * 2004-03-31 2005-10-20 Sony Corp ホログラム記録装置、ホログラム再生装置、ホログラム記録方法、ホログラム再生方法、およびホログラム記録媒体
JP2006164480A (ja) * 2004-12-10 2006-06-22 Fdk Corp ホログラムデータ記録再生装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000098863A (ja) * 1998-09-24 2000-04-07 Fuji Xerox Co Ltd 光記録方法および光記録装置
JP2004361928A (ja) * 2003-05-13 2004-12-24 Optware:Kk 光情報記録方法、光情報記録装置および光情報記録再生装置
JP2005293630A (ja) * 2004-03-31 2005-10-20 Sony Corp ホログラム記録装置、ホログラム再生装置、ホログラム記録方法、ホログラム再生方法、およびホログラム記録媒体
JP2006164480A (ja) * 2004-12-10 2006-06-22 Fdk Corp ホログラムデータ記録再生装置

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