WO2007034435A2 - Compact holographic data storage device. - Google Patents

Compact holographic data storage device. Download PDF

Info

Publication number
WO2007034435A2
WO2007034435A2 PCT/IB2006/053423 IB2006053423W WO2007034435A2 WO 2007034435 A2 WO2007034435 A2 WO 2007034435A2 IB 2006053423 W IB2006053423 W IB 2006053423W WO 2007034435 A2 WO2007034435 A2 WO 2007034435A2
Authority
WO
WIPO (PCT)
Prior art keywords
data storage
holographic data
medium
hds
slm
Prior art date
Application number
PCT/IB2006/053423
Other languages
French (fr)
Other versions
WO2007034435A3 (en
Inventor
Levinus Bakker
Frank Schuurmans
Coen Liedenbaum
Original Assignee
Koninklijke Philips Electronics N.V.
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 Koninklijke Philips Electronics N.V. filed Critical Koninklijke Philips Electronics N.V.
Publication of WO2007034435A2 publication Critical patent/WO2007034435A2/en
Publication of WO2007034435A3 publication Critical patent/WO2007034435A3/en

Links

Classifications

    • 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
    • G03H1/04—Processes or apparatus for producing holograms
    • 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
    • G03H1/04—Processes or apparatus for producing holograms
    • G03H1/0402—Recording geometries or arrangements
    • 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
    • G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
    • G11B7/128—Modulators
    • 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
    • G11B7/1372—Lenses
    • G11B7/1374—Objective lenses
    • 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
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/24003—Shapes of record carriers other than disc shape
    • G11B7/24012—Optical cards
    • 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
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/2403—Layers; Shape, structure or physical properties thereof
    • G11B7/24035—Recording layers
    • G11B7/24044—Recording layers for storing optical interference patterns, e.g. holograms; for storing data in three dimensions, e.g. volume storage
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11C—STATIC STORES
    • G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
    • G11C13/04—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using optical elements ; using other beam accessed elements, e.g. electron or ion beam
    • G11C13/042—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using optical elements ; using other beam accessed elements, e.g. electron or ion beam using information stored in the form of interference pattern
    • 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
    • G03H1/04—Processes or apparatus for producing holograms
    • G03H1/16—Processes or apparatus for producing holograms using Fourier transform
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H2210/00—Object characteristics
    • G03H2210/20—2D object
    • G03H2210/22—2D SLM object wherein the object beam is formed of the light modulated by the SLM
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H2223/00—Optical components
    • G03H2223/18—Prism
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H2223/00—Optical components
    • G03H2223/19—Microoptic array, e.g. lens array
    • 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

Definitions

  • the invention relates to a holographic data storage device.
  • the invention is particularly relevant to minimize the size of holographic read/write drives as well as to minimize the displacement of the optical cards used in holographic data storage devices.
  • Holographic data storage is known to have the potential to obtain large storage densities, fast parallel access, rapid searches in large databases and data encryption.
  • a review of this technology is given in the article of L. Hesselink, S. Orlov and M. Barshaw, "Holographic Data Storage Systems", Proceeding of the IEEE, vol.92, No.8, pp.1231-1280, August 2004.
  • Figure 1 shows a prior art set-up for a compact holographic data storage device.
  • the device of figure 1 comprises a spatial light modulator
  • SLM holographic data storage
  • HDS holographic data storage
  • lens 10 at focal distance from the SLM as well as at focal distance from the HDS medium.
  • each pixel i, j gives rise to a data beam 2Oi, 2Oj which interferes with an off-axis reference beam 30 at a portion 40 of the HDS medium.
  • all the data beams arising from the SLM interfere at the same portion 40 of the HDS medium, resulting in an overlap of all the interference patterns at said portion 40 of HDS medium.
  • This interference pattern is stored in the volume of the holographic medium by means, for instance, of a refractive index modulation.
  • This refractive index modulation contains the information which pixels on the SLM were "0" and "1".
  • the device of figure 1 comprises a second lens position and a detector array.
  • the distance from the medium to the second lens is one focal distance and the distance from this second lens to the detector array is also one focal distance.
  • the device is configured such that upon illumination of the medium with the reference beam only, all the signal beams are reconstructed by diffracting the reference beam of the refractive index modulation and generate the image that was originally on the SLM on the detector array.
  • Multiplexing By multiplexing, a holographic book can be written at this portion 40. Multiplexing can be carried out for instance through angle-multiplexing by varying the angle of incidence of the reference beam 30, or wavelength-multiplexing by changing the wavelength of the light illuminating the SLM and that of the reference beam 30.
  • the card In order to use the full card, i.e. the surface of the HDS medium, the card has to be translated perpendicularly to the optical axis of the device and another book can be written at another portion of the HDS medium.
  • the maximum translation length is in the order of the size of the card.
  • this translation is difficult to perform in a compact portable device.
  • another disadvantage of the set-up of figure 1 is the relatively large focal length of the lens, which is a limitation to the achievement of a very compact holographic drive.
  • the invention provides a holographic data storage device comprising means for receiving a holographic data storage medium, a spatial light modulator split up into a plurality of cells, each cell including a pattern of data pixels and a reference beam area, and a array of lenses disposed substantially at focal distance from said holographic data storage medium and said spatial light modulator, at least one lens being adapted to capture light from one cell so as to interfere data beams and said reference beam at a portion of said holographic data storage medium.
  • the detector part of the device also comprises a plurality of cells, a detector array, and second lens array, the second array of lenses also being substantially disposed at focal distance from said holographic data storage medium and said detector array.
  • the cells of the SLM are much smaller than the entire SLM, lenses with shorter focal length can be used, which makes it possible to have a very compact holographic storage device, as aimed by the invention.
  • a further advantage of the invention consists in that during read-out the displacement of the card is much smaller than in prior art since it is limited to the distance in between two adjacent sub-books associated to two adjacent cells of the SLM.
  • the invention offers the opportunity to have a data card, represented by the HDS medium, larger than the SLM if at least one lens is equipped with a means for shifting said portion of holographic data storage medium further from the optical axis of said lens.
  • Figure 1 is a cross sectional view of a set-up for a holographic data storage device in accordance with the prior art.
  • Figure 2 is a cross sectional view of a set-up for a holographic data storage device in accordance with the invention.
  • Figure 3 is a front view of a spatial light modulator used in the embodiment of figure 2.
  • Figure 4 is an alternative to the embodiment of the set-up of figure 2.
  • a holographic data storage device comprising a holographic data storage HDS medium, a spatial modulator SLM and a array 10 of lenses disposed substantially at focal distance from the HDS medium and the SLM.
  • the device further comprises, not represented in the figures, a detector array and second array of lenses disposed substantially at focal distance from the HDS medium and the detector array.
  • the holographic data storage device of Fig. 2 further comprises means for receiving the HDS medium, which are not shown in Fig. 2 for reasons of convenience. These receiving means are, for example, a table on which the HDS medium can be put. A table such as those conventionally used in CD or DVD players can be used for example
  • the SLM is split up into a plurality of N cells referred to by means of the index K varying between 1 to N, N being taken equal to 9 in the embodiment of figure 3.
  • Each cell K includes a data pattern K ⁇ of pixels i and an area Kr e f directed to the reference beam 30 K emitted by said area Kr ef .
  • the reference areas are also made up of pixels, in accordance with the general structure of the SLM. However, this feature is of no importance for the invention. About half of the SLM pixels are used as reference, the remaining for data.
  • Each lens 10 K of the array 10 is adapted to capture light from one cell K so as to interfere data beams 20 ⁇ ,i emitted by data pixels i of cell K with the associated reference beam 30 K , thus forming a sub-book K at portion 40 K of the HDS medium, the word "book” referring to the entire SLM.
  • the distance between the SLM and the HDS medium can be much smaller, since every lens 10 K only writes a sub- book, i.e. a part of the overall holographic book.
  • the focal distance of the lenses 10 K is about 1 to 2 mm.
  • the SLM now also controls the reference beam and the multiplexing.
  • a holographic book can be written without having to change angles of illumination, wavelengths, etc.
  • the invention enables recording of a large amount of sub-books without requiring any mechanical displacement.
  • a further advantage of this drive is also that during read-out the HDS medium has to be scanned over a much smaller distance than the dimensions of the card, since only the distance in between two sub-books 40 K is to be scanned.
  • the size of the SLM is similar to the size of the HDS card, this resulting from the face to face position of the cells and the corresponding books.
  • said means is a prism 50 K associated to lens 10 K .
  • said means is a prism 50 K associated to lens 10 K .
  • the same result could be achieved by use of mirrors instead of prisms.
  • the lens array 10 can be manufactured for instance by injection molding of a plastic material.

Abstract

The invention relates to a holographic data storage device comprising a holographic data storage (HDS) medium, a spatial light modulator (SLM) split up into a plurality of cells. Each cell (K) includes a pattern (Tdata) of data pixels (i) and a reference beam area (Kref). A array (10) of lenses (10K) is disposed substantially at focal distance from said holographic data storage (HDS) medium and said spatial light modulator (SLM), at least one lens (10K) being adapted to capture light from one cell (K) so as to interfere data beams (20k,i)d said reference beam (30K) at a portion (40K) of said holographic data storage (HDS) medium.

Description

COMPACT HOLOGRAPHIC DATA STORAGE DEVICE
FIELD OF THE INVENTION
The invention relates to a holographic data storage device. The invention is particularly relevant to minimize the size of holographic read/write drives as well as to minimize the displacement of the optical cards used in holographic data storage devices.
BACKGROUND OF THE INVENTION
Holographic data storage (HDS) is known to have the potential to obtain large storage densities, fast parallel access, rapid searches in large databases and data encryption. A review of this technology is given in the article of L. Hesselink, S. Orlov and M. Barshaw, "Holographic Data Storage Systems", Proceeding of the IEEE, vol.92, No.8, pp.1231-1280, August 2004. Figure 1 shows a prior art set-up for a compact holographic data storage device.
For writing the data, the device of figure 1 comprises a spatial light modulator
(SLM) that patterns the data beam, a holographic data storage (HDS) medium and a lens 10 at focal distance from the SLM as well as at focal distance from the HDS medium. When the SLM is illuminated, each pixel i, j gives rise to a data beam 2Oi, 2Oj which interferes with an off-axis reference beam 30 at a portion 40 of the HDS medium. Due to the geometrical configuration of the device, all the data beams arising from the SLM interfere at the same portion 40 of the HDS medium, resulting in an overlap of all the interference patterns at said portion 40 of HDS medium. This interference pattern is stored in the volume of the holographic medium by means, for instance, of a refractive index modulation. This refractive index modulation contains the information which pixels on the SLM were "0" and "1". For read-out, the device of figure 1 comprises a second lens position and a detector array. The distance from the medium to the second lens is one focal distance and the distance from this second lens to the detector array is also one focal distance. The device is configured such that upon illumination of the medium with the reference beam only, all the signal beams are reconstructed by diffracting the reference beam of the refractive index modulation and generate the image that was originally on the SLM on the detector array.
By multiplexing, a holographic book can be written at this portion 40. Multiplexing can be carried out for instance through angle-multiplexing by varying the angle of incidence of the reference beam 30, or wavelength-multiplexing by changing the wavelength of the light illuminating the SLM and that of the reference beam 30.
In order to use the full card, i.e. the surface of the HDS medium, the card has to be translated perpendicularly to the optical axis of the device and another book can be written at another portion of the HDS medium. The maximum translation length is in the order of the size of the card. However, this translation is difficult to perform in a compact portable device. Furthermore, another disadvantage of the set-up of figure 1 is the relatively large focal length of the lens, which is a limitation to the achievement of a very compact holographic drive.
SUMMARY OF THE INVENTION
It is thus an object of the invention to propose a holographic data storage device which would be capable of minimizing the size of the holographic drive so as to make it more compact and also to minimize the displacement of the optical card. To this end, the invention provides a holographic data storage device comprising means for receiving a holographic data storage medium, a spatial light modulator split up into a plurality of cells, each cell including a pattern of data pixels and a reference beam area, and a array of lenses disposed substantially at focal distance from said holographic data storage medium and said spatial light modulator, at least one lens being adapted to capture light from one cell so as to interfere data beams and said reference beam at a portion of said holographic data storage medium. The detector part of the device also comprises a plurality of cells, a detector array, and second lens array, the second array of lenses also being substantially disposed at focal distance from said holographic data storage medium and said detector array. Actually, it will be shown later on that, since the cells of the SLM are much smaller than the entire SLM, lenses with shorter focal length can be used, which makes it possible to have a very compact holographic storage device, as aimed by the invention. Also, a further advantage of the invention consists in that during read-out the displacement of the card is much smaller than in prior art since it is limited to the distance in between two adjacent sub-books associated to two adjacent cells of the SLM. It is worth noting that the invention offers the opportunity to have a data card, represented by the HDS medium, larger than the SLM if at least one lens is equipped with a means for shifting said portion of holographic data storage medium further from the optical axis of said lens.
These and other aspects of the invention will be apparent from and will be elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail by way of example with reference to the accompanying drawings in which :
Figure 1 is a cross sectional view of a set-up for a holographic data storage device in accordance with the prior art.
Figure 2 is a cross sectional view of a set-up for a holographic data storage device in accordance with the invention. Figure 3 is a front view of a spatial light modulator used in the embodiment of figure 2.
Figure 4 is an alternative to the embodiment of the set-up of figure 2.
DETAILED DESCRIPTION OF THE INVENTION
In figure 2 is shown a holographic data storage device comprising a holographic data storage HDS medium, a spatial modulator SLM and a array 10 of lenses disposed substantially at focal distance from the HDS medium and the SLM. For read-out, the device further comprises, not represented in the figures, a detector array and second array of lenses disposed substantially at focal distance from the HDS medium and the detector array. The holographic data storage device of Fig. 2 further comprises means for receiving the HDS medium, which are not shown in Fig. 2 for reasons of convenience. These receiving means are, for example, a table on which the HDS medium can be put. A table such as those conventionally used in CD or DVD players can be used for example
As can be seen in figure 3, the SLM is split up into a plurality of N cells referred to by means of the index K varying between 1 to N, N being taken equal to 9 in the embodiment of figure 3. Each cell K includes a data pattern K^ of pixels i and an area Kref directed to the reference beam 30K emitted by said area Kref. In the embodiment of figure 3, the reference areas
Figure imgf000006_0001
are also made up of pixels, in accordance with the general structure of the SLM. However, this feature is of no importance for the invention. About half of the SLM pixels are used as reference, the remaining for data. Each lens 10K of the array 10 is adapted to capture light from one cell K so as to interfere data beams 20κ,i emitted by data pixels i of cell K with the associated reference beam 30K, thus forming a sub-book K at portion 40K of the HDS medium, the word "book" referring to the entire SLM.
When using a lens array 10, as shown in figure 2, then the distance between the SLM and the HDS medium can be much smaller, since every lens 10K only writes a sub- book, i.e. a part of the overall holographic book. For example, the focal distance of the lenses 10K is about 1 to 2 mm.
It should be noted that the SLM now also controls the reference beam and the multiplexing. Hence, in the set-up of figure 2, a holographic book can be written without having to change angles of illumination, wavelengths, etc. As can be readily understood, the invention enables recording of a large amount of sub-books without requiring any mechanical displacement. A further advantage of this drive is also that during read-out the HDS medium has to be scanned over a much smaller distance than the dimensions of the card, since only the distance in between two sub-books 40K is to be scanned.
An example of multiplexing that can be used in connection with the invention is given in the article of H. Horimai and J. Li, "A Novel Collinear Optical Setup for Holographic Data Storage System", ICO 2004, Technical Digest.
In the embodiment of figure 2, the size of the SLM is similar to the size of the HDS card, this resulting from the face to face position of the cells and the corresponding books. By using lenses equipped with a means for shifting the corresponding sub-books further from the optical axis of the lenses, it is possible to have a data card larger than the SLM.
In the embodiment of figure 3, said means is a prism 50K associated to lens 10K. The same result could be achieved by use of mirrors instead of prisms.
The lens array 10 can be manufactured for instance by injection molding of a plastic material.

Claims

1. A holographic data storage device comprising means for receiving a holographic data storage (HDS) medium, a spatial light modulator (SLM) split up into a plurality of cells, each cell (K) including a pattern (TQata) of data pixels (i) and a reference beam area (Kref), and a array (10) of lenses (10K) disposed substantially at focal distance from said holographic data storage (HDS) medium and said spatial light modulator (SLM), at least one lens (10K) being adapted to capture light from one cell (K) so as to interfere data beams (2Oκ,0 an^ said reference beam (30K) at a portion (40K) of said holographic data storage (HDS) medium.
2. A holographic data storage device as claimed in claim 1, wherein at least one lens (10κ) is equipped with a means (50K) for shifting said portion (40K) of holographic data storage (HDS) medium further from the optical axis of said lens (10K).
3. A holographic data storage device as claimed in claim 2, wherein said means for shifting said portion of holographic data storage medium is a prism (50K).
4. A holographic data storage device as claimed in claim 2, wherein said means for shifting said portion of holographic data storage medium is a mirror.
PCT/IB2006/053423 2005-09-23 2006-09-21 Compact holographic data storage device. WO2007034435A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP05300765.4 2005-09-23
EP05300765 2005-09-23

Publications (2)

Publication Number Publication Date
WO2007034435A2 true WO2007034435A2 (en) 2007-03-29
WO2007034435A3 WO2007034435A3 (en) 2009-03-05

Family

ID=37889233

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2006/053423 WO2007034435A2 (en) 2005-09-23 2006-09-21 Compact holographic data storage device.

Country Status (1)

Country Link
WO (1) WO2007034435A2 (en)

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0720765A (en) * 1993-06-28 1995-01-24 Internatl Business Mach Corp <Ibm> Phase-coded solid horogram system having binary phase modulator
WO2001037033A2 (en) * 1999-11-18 2001-05-25 Corning Applied Technologies Spatial light modulator
WO2004112045A2 (en) * 2003-06-07 2004-12-23 Aprilis, Inc. High areal density holographic data storage system

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
H. HORIMAI; J. LI: "A Novel Collinear Optical Setup for Holographic Data Storage System", TECHNICAL DIGEST., 2004
L. HESSELINK; S. ORLOV; M. BARSHAW: "Holographic Data Storage Systems", PROCEEDING OF THE IEEE, vol. 92, no. 8, August 2004 (2004-08-01), pages 1231 - 1280

Also Published As

Publication number Publication date
WO2007034435A3 (en) 2009-03-05

Similar Documents

Publication Publication Date Title
CN100403410C (en) Method and device for recording and reproducing holographic data
US5995251A (en) Apparatus for holographic data storage
KR101039074B1 (en) High data density volumetric holographic data storage method and system
US6538776B2 (en) Self-referenced holographic storage
US20050036182A1 (en) Methods for implementing page based holographic ROM recording and reading
US20050270609A1 (en) Holographic recording system having a relay system
KR20010071211A (en) System and method for recording of information on a holographic recording medium, preferably an optical card
CA2222085A1 (en) Optical data storage medium and methods for its writing and reading
US6055174A (en) Solid state holographic memory
KR100304469B1 (en) Systems and methods for manipulating focal plane data to access data locations in holographic memory
KR100295489B1 (en) Systems and methods for manipulating Fresnel area data to access data locations in holographic memory
CN100435043C (en) Picture reproducing device and method
CN1973324A (en) Phase-conjugate read-out in a holographic data storage
CN101529509A (en) Setup and methods for storing data in and reading out data from a holographic storage arrangement
KR101230508B1 (en) Data page pixel shaping for holographic recording
US7428206B2 (en) Holographic information recording apparatus
WO2007034435A2 (en) Compact holographic data storage device.
CN101159147B (en) Compact apparatus for reading from and/or writing to holographic storage media
US6040930A (en) Volume holographic storage using rotated signal beam encoder
US5896210A (en) Molded block optical system for volume holographic storage
CN100511438C (en) Holographic system, in particular for holographic data storage
CN101188127A (en) Beam shifting element for an optical storage system
US7773274B2 (en) Apparatus and method to store information in a holographic data storage medium
KR20010021350A (en) Using the talbet effect for lensless imaging of periodic structures in a holographic memory system
WO2006071440A1 (en) System and method for parallel selection and retrieval of data stored in a holographic data storage medium

Legal Events

Date Code Title Description
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 06796042

Country of ref document: EP

Kind code of ref document: A2