WO1997001133A1 - Systeme et procede de copie d'hologrammes multiplexes - Google Patents

Systeme et procede de copie d'hologrammes multiplexes Download PDF

Info

Publication number
WO1997001133A1
WO1997001133A1 PCT/US1996/010410 US9610410W WO9701133A1 WO 1997001133 A1 WO1997001133 A1 WO 1997001133A1 US 9610410 W US9610410 W US 9610410W WO 9701133 A1 WO9701133 A1 WO 9701133A1
Authority
WO
WIPO (PCT)
Prior art keywords
medium
master
multiplexing
multiplexed
holograms
Prior art date
Application number
PCT/US1996/010410
Other languages
English (en)
Inventor
Fai H. Mok
Yong Qiao
Gan Zhou
Demetri Psaltis
Original Assignee
Holoplex
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 Holoplex filed Critical Holoplex
Priority to AU63342/96A priority Critical patent/AU6334296A/en
Priority to EP96922483A priority patent/EP0835479A4/fr
Priority to JP9503883A priority patent/JPH11515110A/ja
Publication of WO1997001133A1 publication Critical patent/WO1997001133A1/fr

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
    • G11B7/28—Re-recording, i.e. transcribing information from one optical record carrier on to one or more similar or dissimilar record carriers
    • 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
    • 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
    • G03H1/02—Details of features involved during the holographic process; Replication of holograms without interference recording
    • G03H1/024—Hologram nature or properties
    • G03H1/0248—Volume 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
    • G03H1/20—Copying holograms by holographic, i.e. optical means
    • G03H1/202—Contact copy when the reconstruction beam for the master H1 also serves as reference beam for the copy H2
    • 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
    • G11B7/125—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
    • G11B7/127—Lasers; Multiple laser arrays
    • 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
    • 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
    • G03H2001/2675—Phase code multiplexing, wherein the sub-holograms are multiplexed according to spatial modulation of the reference beam

Definitions

  • the present invention relates to the field of optical storage, and more specifically, to a copying system for high density and high speed optical memory based on multiplexed volume holography.
  • Information technology comprises primarily three elements: information communication, information processing, and information storage.
  • information technology has relied on electrons as the main information carriers and electronic devices as main means for communication, processing, and storage.
  • photons and optical devices are making their way into information technology related applications because of their high speed in data transferring and processing, insensitivity to electromagnetic interference, and capability of massive parallel processing.
  • optical fibers are widely used for local and wide area networks and also for telecommunications. In fact, optical fibers form the backbone of many modern communication systems.
  • Integrated optical electronic devices based on semiconductor wafer technology and diode laser technology have been used for optical communication and optical data processing.
  • Photonic technology is also used in applications that require massive data manipulation such as in image processing and machine vision.
  • optical compact discs provide high density and convenience for digital data storage at low cost.
  • optical compact discs are limited in its data accessing speed and capacity of storage for many applications.
  • the demand for a higher density storage and high speed data access capability stimulates much research and development in data storage technology.
  • Examples of such effort in optical storage include using shorter wavelength diode laser for compact disc systems, better digital data compression algorithm, and multilayer compact disc systems.
  • the improvements brought about by these will not meet the requirements in data storage for future applications in information technology.
  • Optical holography is one such approach.
  • the present invention relates to the use of optical devices for information storage and to convenient and reliable reproduction of large amount of information stored in multiplexed holograms.
  • Optical memory based on holography utilizes interference of coherent light to store information in the form of the amplitude and phase of light.
  • Holographic memories can store hundreds of billions of bytes of data, transfer them at a rate of a billion or more bytes per second and select a randomly chosen data element in less than 100 microseconds. Other memory technologies can rarely offer all three of this advantages.
  • FIG. 1 shows the formation and reconstruction of a hologram known to the art.
  • the holographic medium 100 is a piece of photosensitive material.
  • the object 110 is an object whose information is to be recorded in the hologram medium 100.
  • Two mutually coherent beams are used to form the hologram in the holographic medium 100.
  • An object beam 120 carries the information in the object 110 to intersect with a reference beam 130 in the holographic medium 100.
  • the reference beam 130 does not carry information and is normally a plane wave.
  • the interference of the object beam 120 and the reference beam 130 forms interference patterns inside the holographic medium 100.
  • the intensity variation patterns thereof are recorded by the photosensitive medium 100.
  • a hologram containing information of the object 110 is formed inside the holographic medium 100.
  • Figure lb illustrates reconstruction of the hologram.
  • a read beam 140 that has the same wavelength and wave vector as the original reference beam 130 impinges on the holographic medium 100.
  • the interaction of the beam 140 and the holographic grating recorded in the holographic medium 100 generates a diffracted beam 150.
  • the diffracted beam 150 carrying the information of the object 110, propagates in the direction of the original object beam 120.
  • a reconstructed virtual image 160 identical to the original object 110 appears at the - 4 - same location where the object 110 is and can be viewed in the diffracted beam 150.
  • the information in the hologram 100 can be two dimensional or three dimensional.
  • a phase matching condition is required to read the information in a holographic medium.
  • This Bragg condition requires the read beam to impinge on the holographic medium 100 at a particular angle in order to read the holographic information contained therein with maximum diffraction efficiency and optimal fidelity. Deviation from the proper Bragg angle for a specific hologram results in degraded reconstruction including reduced diffraction efficiency. For a thin holographic medium whose thickness is less than the spacing of the interference fringes in recorded holograms, this requirement in the direction of the read beam is not strict.
  • the gratings contained in the holograms in a thin medium are said to be two dimensional.
  • the holographic gratings are formed in all directions and three dimensional volume holographic gratings are formed within the thick medium.
  • the angular selectivity in the direction of the read beam for a particular hologram becomes more sensitive in a thick medium.
  • the Bragg conditions of a thick holographic medium allow recording multiple images in the same volume in a holographic medium. Retrieving a particular holographic information is accomplished by illuminating the holographic grating with a read beam at a proper Bragg angle.
  • angular multiplexing The above method of using the angular selectivity of a thick hologram to record multiple images in a medium is called angular multiplexing.
  • Many other multiplexing techniques can be used to increase the information storage capacity of thick holographic media.
  • Multiplexing techniques based on changing the angle of an incident reference beam include fractal multiplexing and peristrohpic multiplexing. Examples of other multiplexing methods are shift multiplexing, phase-code multiplexing, and wavelength multiplexing. Any one of the above multiplexing techniques or combinations thereof can be used.
  • the properties of a holographic medium in consideration and the specific requirements of a particular application dictate the choice of multiplexing methods. For convenience of discussion, any of the multiplexing techniques mentioned above and other similar multiplexing methods including combinations thereof are referred to as "volume multiplexing" or simply "multiplexing" throughout this disclosure.
  • the maximum number of images that can be stored at the same location inside the holographic medium is limited.
  • One reason for this limitation is the limited dynamic range of the holographic medium. As more holograms share the same recording volume, the strength of each hologram diminishes. Specifically, the percentage of the light that is deflected by each hologram, i.e., the efficiency of the holographic grating, is inversely proportional to the square of the number of holograms superimposed at that location.
  • One method to further increase the storage capability of a holographic medium is to utilize spatial multiplexing techniques in combination with volume multiplexing methods. Multiple holograms are recorded at a plurality of spatially separate or partially overlapped locations inside a hologram medium with each location having volume multiplexed holograms. Such a double multiplexed holographic memory system can achieve high storage capacity that is not obtainable by many other non-holographic techniques. For example, the inventors of the present invention have demonstrated a system in which 10,000 data pages are stored in each of 16 locations, for a total of 160,000 holograms.
  • optical volume holographic storage is the rapid random access by nonmechanical means. For example, high frequency acoustic waves in solids are used to deflect a reference light beam in order to select and read out a selected page of data in tens of microseconds. This is much faster than the access time of tens of milliseconds that is typical for a mechanical readout head in today's optical and magnetic discs.
  • optical volume holographic memories have advantages over other memory technologies in terms of storage capacity and random access time.
  • one important advantage of the compact disc technology and magnetic memories is that information can be copied without any complicated system at very low cost.
  • CD-ROM and compact audio discs can be fabricated by injection molding , making them inexpensive to reproduce.
  • copying multiplexed holograms often involves a complicated optical system and due precaution has been required to ensure the preservation of the exact phase and amplitude information during the reproduction process.
  • the present invention discloses a hologram copying system and method for multiplexed volume holograms with improved performance, a simpler optical set-up and lower cost.
  • the inventors of the present invention recognized the importance of the simplicity of the optical set up in a hologram copying system.
  • the inventors recognized, importantly, that the replicate hologram must faithfully reproduce the images of the original object and the information therein, and that the replicate holograms do not necessarily have to contain the identical phase and amplitude information as the original holograms.
  • the inventors further recognized the importance of the capability of simultaneously copying spatially multiplexed holograms with each holographic spatial unit having multiple volume multiplexed holograms.
  • the present invention employs only one coherent read beam to duplicate a master medium to a replicate medium.
  • This beam for duplication is substantially identical to the original reference beam used in creating the master medium in terms of beam parameters such as wavelengths, wave vectors, and phase values.
  • the transmitted beam of the read beam will overlap and interfere with the diffracted beam from the master medium in a region and a replicate hologram is formed with replicated medium placed therein.
  • the master medium has volume multiplexed holograms and requires one read beam or multiple mutually incoherent but individually coherent read beams that satisfy the Bragg phase matching conditions for reconstruction and accordingly for duplicating the master medium to a replicate medium.
  • the mutually incoherent beams are necessary in order to eliminate cross-talk between superimposed gratings at the same location.
  • the replicating read beam or read beams must have a diameter that is large enough to cover the entirety of the original hologram and the diffracted object beams at the replicate holographic medium.
  • This also allows the present invention to be able to copy multiple holograms simultaneously, which is not possible for the cited prior art systems. It is, therefore, preferential to place the replicate holographic medium close to the original master medium in order to limit the width of the read beam required and thus to reduce the power requirement for the laser source.
  • Another advantage of placing the replicate medium close to the master medium is a simplified system and more reliable performance.
  • the amplitude and phase distributions of the replicate hologram are different from that of the master medium since they capture different slides of the original object beam.
  • the present invention only duplicates the information from the master medium that is necessary to form the identical images of the objects that are used to produce the original master mediums. Therefore, the present invention does not require complicated, multi-element precision imaging systems that are necessary in prior art copying systems for multiplexed holograms.
  • the much simpler setup in the present invention significantly enhances the reliability and robustness of the system and reduces the cost.
  • the present invention is capable of duplicating a large amount of information which has not been difficult to achieve in prior art systems due to - li ⁇ the limited space-bandwidth product of the imaging system.
  • the distance between the master medium and the replicate medium is unimportant to faithfully copying the holographic information of a hologram in preferred embodiments of the present invention using transmission mode, whereas prior copying systems for multiplexed holograms are highly sensitive to this distance.
  • Figure 1 shows a basic system for recording on a master recording medium and reading out therefrom;
  • Figure 2 shows a layout of a simple copying system used in the present invention, for a single beam recording;
  • Figure 3 shows the first embodiment of the present invention
  • Figure 4 shows the second embodiment of the present invention
  • Figure 5 shows the third embodiment of the present invention
  • Figure 6 shows the fourth embodiment of the present invention.
  • Figure 7 shows a modification of the present invention.
  • Description of Preferred Embodiments Figure 2 illustrates the basic building blocks for copying multiple holograms in the present invention.
  • a master medium 100 is recorded as shown in Figure la.
  • a replicating read beam 210 that is substantially similar to the original reference beam 130 of Figure la is used for duplication of the master medium 100 to a replicate medium 200.
  • the replicate medium 200 is preferably placed close to the master medium 100 although the distance between them is not critical to the implementation of the present invention.
  • the interaction of the beam 210 and the master medium 100 produces a diffracted beam 230 that is substantially identical to the original object beam 120 on the right- hand side of the master hologram 100 in Figure la.
  • a virtual image 240 identical to the original object 110 of Figure la is formed at the same location where the original object 110 is placed in recording the master medium.
  • a portion of the replicating read beam 210 passes through the master medium 100 as the transmitted beam 220.
  • the interference between the transmitted beam 220 and the diffracted beam 230 forms an interference optical field in a region where the two beams overlap with each other.
  • the replicate medium 200 that is made of a photosensitive material captures the interference pattern and a copy of the master medium 100 is therefore obtained.
  • the position of the replicate medium 200 is flexible as long as the read beam 210 is broad enough to cover the original holographic gratings in the master medium 220 and the replicate medium 200.
  • the space-bandwidth product of the system is large since there is no imaging optics placed between the master medium 100 and the replicate medium 200.
  • the holographic gratings recorded in the replicate medium 200 are different in phase and amplitude distributions from the holographic gratings contained in the master medium 100 although both contain the same information of the original object 110. Therefore, the current invention duplicates the holographic information in the master hologram without exactly copying the phase and amplitude distributions of the master hologram.
  • the present invention is able to duplicate multiple spatially multiplexed holograms in a master medium to a replicate medium with a read beam of broad cross-section area due to the large spatial bandwidth product of the system.
  • each spatial unit thereof contain a plurality of volume multiplexed holograms. This requires a plurality of replicating read beams with each being substantially identical to the corresponding reference beams used in creating the original hologram.
  • One unique feature of the current invention is the capability of simultaneously duplicating a large amount of holograms that are spatially multiplexed and volume multiplexed. The inventors of the present invention have successfully demonstrated the invention with prototype copying systems.
  • R_ are unit amplitude plane waves
  • c i;j are complex constants.
  • the master holograms can be recorded with any object beams. According to the present invention, however, there is one condition on the relationship between the N plane reference beams to minimize the cross-talk between spatially superimposed holograms.
  • Each of the N plane waves is chosen in such a way that the diffraction efficiency of the i-th hologram recorded by the corresponding i-th reference beam R_ is below a predetermined small threshold that is substantially smaller than its optimal diffraction efficiency if the j-th reference beam R j different from R_ (i ⁇ j) is used for reconstruction thereof.
  • Equation (1) The corresponding hologram contained in equation (1) can be represented by
  • the holographic medium is illuminated by a collection of N plane waves that are mutually incoherent to each other, which can be represented by:
  • Equation (7) The second term in Equation (7) is the reconstruction of the gratings S j R_ * by Bragg-mismatched plane waves R n and therefore the corresponding signals are essentially zero.
  • the first term of Equation (7) represents the reconstruction signals that satisfy the Bragg conditions. Since ⁇ has unit amplitude, the reconstruction signals are
  • the reconstructed signals can be expressed as
  • D (S j ) represent the propagation effects including phase change and Fresnel diffraction as the beams travel from the original hologram to the replicate medium.
  • D (S j ) and S j are different from each other in both amplitude and phase distributions.
  • the transmitted reference beams are represented by
  • T n is the transmission coefficient of the original medium and ⁇ n is the phase change due to wave propagation.
  • the interference patterns formed by the reconstructed signal beams in Equation (9) and the transmitted reference beams in Equation (10) at the replicate holographic medium is
  • the replicate medium records the interference patterns and the corresponding holograms are proportional to
  • T T is constant for all plane waves since the holograms in the original medium share a common volume.
  • Equation (12) The recorded holograms contained in Equation (12) can be expressed as the following since the time- averaging contribution from the terms with n ⁇ i in Equation (12) goes to zero:
  • Equation (13) represents holograms that can reconstruct the images of the original objects under illumination by proper read beams.
  • Equation (13) is indicative of the recordings at the replicate medium as if the original objects were present.
  • the replicate holograms in Equation (3) the replicate holograms in
  • Equation (13) differ from the original holograms in both phase and amplitude distributions. Another important implication thereof is that the exact location of the replicate medium relative to the original hologram is unimportant and different locations introduce different amplitude distribution D(S j ) and phase ⁇ i.
  • the present invention allows a faithful duplication of multiplexed master holograms recorded with plane reference waves if the duplicating read beams are also plane waves and preserve the same relationship as the original reference beams (e.g., a certain angle separation therebetween in angular multiplexing) . If the original reference beams have a relationship relative to each other to minimize the cross-talk effect, the duplicated holograms using the present invention will have a minimized cross-talk effect as well. Otherwise, the cross-talk in the master holograms will be also copied in the duplicated holograms in the present invention. Furthermore, it shows that the copied holograms in the present invention are different from the originals but the holographic information thereof is identically replicated.
  • Figure 3 shows the first embodiment of the present invention for duplicating volume multiplexed holograms.
  • a master medium 300 contains a plurality of volume multiplexed holograms.
  • the volume multiplexing technique can be any one selected from a group comprising angular multiplexing, fractal multiplexing, peristrohpic multiplexing, shift multiplexing, phase- code multiplexing, wavelength multiplexing, and any combination thereof. Detailed descriptions of these multiplexing techniques are given in the following references:
  • Wavelength multiplexing G.A. Rakuljic, V. Leyva, and A. Yariv, "Optical data storage by using orthogonal wavelength-multiplexed volume holograms, " Optics Letters, Vol.17, pp.1471, 1992;
  • Fractal multiplexing F.H. Mok, "Angle-multiplexed storage of 5000 Holograms in lithium niobate", Optics Letters, Vol.18 (11), pp.915-917, 1993; Shift multiplexing, D. Psaltis, M. Levene, A. Pu, G. Barbastathis, and K. Curtis, "Holographic storage using shift multiplexing", Optics Letters, Vol.20(7), pp.l, 1995; and Peristrophic multiplexing, K. Curtis, A. Pu, and D. Psaltis, “Method for holographic storage using peristrophic multiplexing", Optics Letters, Vol.19 (13), pp.993-994, 1994.
  • an object data input module 302 is employed to update the object images in accordance with different reference beams.
  • Two reference beams, 306 and 308, are shown in Figure 3a to represent a plurality of reference beams used in recording the master medium 300.
  • the optical beams for both recording the master medium 300 or duplicating the replicate 310 are generated either by a single laser or a plurality of lasers including diode lasers, laser diode arrays, and diode-pumped solid-state lasers.
  • the object input module 302 can be a real object or a spatial light modulator.
  • the first hologram is recorded as follows.
  • the object module 302 inputs the first object image via the object beam 304.
  • the first reference beam 306 that is coherent with the object beam 304 is directed to the master recording medium 300.
  • the master medium 300 captures the interference pattern of the object beam 304 imprinted with the first object image and the first reference beam 306.
  • the object module 302 replaces the first object image with the second object image which is imprinted onto the object beam 304.
  • a second reference beam 308 having a different relationship with the first reference beam 306 in terms of volume multiplexing is directed to the master recording medium 300 without the presence of any other reference beams.
  • volume multiplexing e.g., incident angle, wavelength, etc.
  • the second reference beam 308 is incident at an angle at which the diffraction efficiency of the first hologram for second reference beam 308 is substantially reduced and below a predetermined small threshold value.
  • wavelength multiplexing the second reference beam 308 is at a different wavelength from the first reference beam 306 that the diffraction efficiency of the second reference beam 308 from the first hologram grating is substantially reduced and below a predetermined small threshold value.
  • the hologram of the second object is therefore recorded in the same recording volume or superimposed with the first hologram. Therefore, each multiplexed hologram is associated with a reference beam with a characteristic unique to that multiplexed hologram.
  • the above recording procedure is repeated until all volume multiplexed holograms are superimposed in the same volume inside the master recording medium. Recording of the master medium 300 is then completed.
  • each multiplexed hologram is recorded with multiple reference beams.
  • the phase-code of every set of reference beams is orthogonal to other sets used in recording.
  • FIG. 3b illustrates the duplication process.
  • a sample stage 320 holds the master medium 300 and a
  • a plurality of replicating read beams corresponding to the original writing reference beams are used for duplicating the master medium 300 to the 0 replicate medium 310.
  • Two replicating read beams, 316 and 318, are shown therein as examples.
  • the replicating read beams are substantially identical to their corresponding writing reference beams except they can have larger cross-section area in order to cover the 5 entire replicate medium 310 for a faithful copy.
  • the replicating read beams preserve the relative relationship between the original reference writing beams. Therefore, each replicating read beam processes a characteristic uniquely associated with one 0 of the multiplexed holograms stored in the master medium 300.
  • This beam characteristic can be the frequencies, wave vectors, relative phases, and other parameters of the replicating beams or any combination thereof.
  • one such characteristic in a replicating read 5 beam can be the incident angle associated with a particular angularly multiplexed hologram.
  • the wavelength of a replicating read beam is one such beam characteristic uniquely associated with a particular wavelength multiplexed hologram.
  • Bragg phase-matching condition is satisfied for angular multiplexed holograms since the wave vector and wavelength of a replicating read beam is the same as its corresponding writing reference beam in making an angularly multiplexed master hologram.
  • the replicate medium 310 is preferably close to the master medium 300 for duplication.
  • An optional spacer 322 is shown in Figure 3b for maintaining a small spacing between the master medium 300 and the replicate medium 310 and ensuring mechanical stability in conjunction with a sample holding stage 320. Moreover, the replicate medium 310 can be held against the master medium 300 on the sample stage 320 without the optional spacer 322.
  • a replicate hologram is produced by exposing a piece of unexposed holographic medium 310 simultaneously to the replicating read beams, 316, 318, etc.
  • the interference patterns between the diffracted beams and the transmitted beams are recorded and further processed.
  • the exact order to which the multiplexed master holograms are recorded is not important as far as the replicating process described in the present invention is concerned.
  • the hologram duplicating system and method of the present invention will work with a set of multiplexed holograms recorded in a master medium by any multiplexing techniques as long as the relationship between the plane reference writing beams are preserved in the replicating beams.
  • some advantages of present invention include the ability to duplicating a large amount of holographic information simultaneously, capability of spatial and volume multiplexing of volume holograms, simple optical system, and easy operation.
  • the transmission copying scheme used in the present invention is relatively insensitive to vibrations and the spacing between the master medium 300 and the replicate medium 310. Any phase changes introduced to the replicating read beams, 316, 318, etc., are automatically transmitted to the phase of the reconstructing diffracted beams. Consequently, the phase differences between the writing beams at the replicate medium 310 remains constant.
  • Figure 4 shows the second embodiment of the present invention for duplicating spatially multiplexed holograms.
  • a master holographic medium 400 contains a plurality of spatial units with two adjacent units having no or partial overlap with each other. Each spatial unit is recorded with a hologram containing holographic information of an object image. All holograms in the master 400 are recorded with reference writing beams having the same beam characteristics such as wavelengths, wave vectors, and relative phases.
  • an unexposed replicate holographic medium 410 is placed on a sample stage 320.
  • the replicate medium 410 is preferably close to the master medium 400 for duplication.
  • An optional spacer 322 is shown in Figure 4 for maintaining a small spacing between the master medium 400 and the replicate medium 410 and ensuring mechanical stability. Moreover, the replicate medium 410 can be held against the master medium 400 on the sample stage 320 without the optional spacer 322.
  • a replicating read beam 402 substantially identical to the original reference beams in beam characteristics such as frequencies, wave vectors, and relative phases is used for duplication.
  • the replicating read beam 402 has a broader cross-section than that of the original reference beams to illuminate all the spatial holographic units in the master medium 400 and the recording portion of the replicate medium 410 that is illuminated by the diffracted beams and transmitted beam 403. This is to ensure that the copied holograms in the replicate medium 410 have high fidelity to the master medium 400.
  • a plurality of interference patterns between the transmitted replicating beam 403 and a plurality of diffracted beams (e.g., beam 421) from each spatial holographic unit (e.g., unit 420) are recorded in the replicate medium 410 simultaneously.
  • the phase and amplitude distributions of the replicated holograms in the replicate medium 410 are different form the master holograms in the master medium 400 but both contain the same information of the original objects.
  • FIG. 5 is the third embodiment of the present invention.
  • a master medium 500 contains a plurality of spatial units with two adjacent units having no or partial overlap with each other.
  • Each spatial unit is recorded with a plurality of holograms using volume multiplexing techniques and any combination thereof.
  • P spatial units there are P spatial units and each unit has Q volume multiplexed holograms.
  • the total number of holograms stored is given by PQ.
  • Such "double multiplexing" used in the present invention significantly increases the storage capability of holographic memories.
  • P objective beams imprinted with a first set of P images out of PQ images are used to illuminate P spatial units in the master holographic medium, respectively.
  • the same volume multiplexing technique is used for all P spatial units in recording the corresponding holograms.
  • a reference beam in coherence with all P objective beams has a large cross-section area to illuminate the portion of the master holographic medium illuminated by P objective beams.
  • the interference of the broad reference writing beam and P objective beams form P holograms in P spatial units.
  • a narrow reference beam in coherence with the objective beams can be used to record the master holograms in each spatial unit one by one. Recording of the first P holograms in P spatial units is thus completed.
  • a second set of P objective beams carrying a different set of P images out of the remaining P(Q-l) images are sent to the P spatial units, respectively.
  • a second volume multiplexing technique is applied to record P holograms in the P spatial units, respectively.
  • this second volume multiplexing technique is not necessarily the same as the first volume multiplexing technique used in recording the first set of P holograms therein.
  • a second broad cross- section reference writing beam interferes with the second set of P objective beams to form a second set of P holograms in the P spatial units.
  • a second narrow cross-section reference writing beam can be used to record the second set of P holograms in each spatial unit one by one.
  • the second reference writing beam can have different beam characteristics (e.g., wavelength, wave vector, etc.) from the first reference writing beam depending on the second volume multiplexing technique used. Repeat the above processes to record the remaining P(Q-2) images.
  • the exact order to which the multiplexed master holograms are recorded is not important as far as the replicating process described in the present invention is concerned.
  • the hologram duplicating system and method of the present invention will work with a set of multiplexed holograms recorded in a master medium by any multiplexing techniques as long as the relationship between the plane reference writing beams are preserved in the replicating beams.
  • P mutually incoherent but individually coherent replicating read beams are used.
  • One or a plurality of coherent light sources can be used including diode lasers, diode laser arrays, and diode-pumped solid-state lasers.
  • Two replicating read beams, 530 and 540, are shown in Figure 5 as examples.
  • the replicating beams have substantially identical beam characteristics (e.g., wavelength and wave vector) to the original reference beams, respectively. Therefore, each replicating read beam processes a characteristic uniquely associated with one of the multiplexed holograms stored in the master medium 300.
  • one such characteristic in a replicating read beam can be the incident angle associated with a particular angularly multiplexed hologram.
  • the wavelength of a replicating read beam is one such beam characteristic uniquely associated with a particular wavelength multiplexed hologram.
  • the cross-sections of the read beams are bigger than those of the reference beams for faithful duplication as described previously therein.
  • the master medium 500 and the replicate medium 510 are held close to each other on a sample stage 320.
  • An optional spacer 322 is shown in Figure 5.
  • the implementation of the present invention allows an arbitrary spacing between the master medium 500 and the replicate medium 510.
  • the master medium 500 can be held against the replicate medium 510 on the sample stage 320 without the optional spacer 322.
  • each of Q transmitted replicating read beam (e.g., beam 531 from beam 530 or beam 541 from beam 540) interferes with P diffracted beams resulted from the interaction of Q mutually incoherent replicating read beams and a total of PQ holographic gratings in the master medium 500.
  • a spatial unit 520 in the master medium 500 contains Q volume multiplexed holograms which simultaneously interact with all Q replicating read beams 530, 540, etc., respectively. All P spatial units are undergoing the same process at the same time. Hence a total of PQ holograms will be duplicated in the replicated medium 510 simultaneously.
  • the replicate medium 510 will also have P spatial units with each having Q volume multiplexed holograms. Unlike the master medium 500, the duplicated holograms in the replicate medium 510 have different phase and amplitude distributions from the corresponding original holograms as described earlier.
  • a fourth embodiment of the present invention is illustrated in Figure 6. In both creating the master medium 600 and reconstructing the replicate hologram
  • FIG. 610 an identical Fourier lens is used.
  • Figure 6a shows the recording process of the master hologram.
  • a spatial light modulator (SLM) 604 is used to imprint either an image of a real object or a computer generated pattern to a coherent beam.
  • a Fourier lens 602 is placed at a distance equal to the focal length from the SLM 608.
  • a recording medium for the master hologram is on the other side of the lens 602 at a distance of focal length. In this setup, the input image on the SLM 604 is Fourier- transformed to the Fourier plane wherein the master recording medium is located.
  • each spatial component of the object wave emitted by the input image in the SLM 604 is transformed into a plane wave by the Fourier lens 602.
  • High spatial frequency components containing information of the fine features in the image are transformed into plane waves having large angles with respect to the optic axis of the Fourier lens 602.
  • a reference beam 606 interferes with all the plane object beams (e.g., beam 609) and the corresponding interference patterns are recorded.
  • a mater hologram 600 is obtained.
  • the reference beam 606 can have any wavefront but a plane wave is preferred.
  • the Fourier holograms in the master medium 600 are plane-wave gratings.
  • Spatial multiplexing, volume multiplexing techniques, or any combination thereof is used to store a plurality of images in the master medium 600 as described in other preferred embodiments.
  • the exact order to which the multiplexed master holograms are recorded is not important as far as the replicating process described in the present invention is concerned.
  • the hologram duplicating system and method of the present invention will work with a set of multiplexed holograms recorded in a master medium by any multiplexing techniques as long as the relationship between the plane reference writing beams are preserved in the replicating beams.
  • Figure 6b shows the duplicating process similar to the systems described in other embodiments.
  • a sample stage 320 holds the master medium 600 and a replicate medium 610 close together.
  • An optional spacer 322 is shown to maintain a constant small spacing between the media.
  • an arbitrary spacing between the master medium 600 and the replicate medium 610 is allowed in the present invention.
  • the master medium 600 can be held against the replicate medium 610 on the sample stage 320 without the optional spacer 322.
  • At least one replicating read beam (e.g., beam 620) corresponding to the original reference beam (e.g., beam 606) is used for duplication.
  • An unexposed replicate medium 610 records the interference patterns between the transmitted replicating beams and the diffracted beams (e.g., beam 630) from the master medium 600. All multiplexed holograms in the master medium 600 are duplicated to the replicate medium 610 simultaneously.
  • a Fourier lens 640 substantially identical to the lens 602 is used as shown in Figure 6c.
  • the replicate hologram 610 is placed in a first Fourier plane of the lens 640 and a photodetector array 660 is placed in a second Fourier plane thereof.
  • the present invention can be applied to duplicate multiplexed holograms using reflection mode instead of transmission mode.
  • the replicate medium is placed in between the master hologram and the laser sources in the reflection mode.
  • the spacing between the master medium and the replicate medium cannot be arbitrarily large and is limited within to the half of the coherence length of the laser sources that generate the replicating read beams. This is to ensure the stability of the interference patterns to be recorded at the replicate medium.
  • collimating optics may be used to convert a laser beam from each laser source into a plane wave.
  • the collimating optics can be one or a plurality of lenses including lens array, one or a plurality of curved mirrors, one or a plurality of diffractive optical elements including an array of diffractive optic elements, or a combination of any these elements.
  • the laser sources for the present invention can be a variety of lasers to the appropriate wavelengths and beam characteristics for a specific application.
  • Laser diode based laser systems are preferred for their compactness and ease of use and maintenance comprising diode lasers, diode laser arrays, diode pumped solid-state lasers including diode pumped fiber lasers, and any combination thereof.
  • Figure 7 shows one such example in which a replicating system for angular and peristrophic multiplexed holograms using diode lasers based on the present invention.
  • the laser diodes e.g., laser diode 700
  • the laser diodes are positioned such that their emissions are collimated by a single lens 710 into plane waves which satisfy the Bragg-matching conditions the angle multiplexed holograms recorded in the master medium 720.
  • the number of laser diodes is equal to the number of multiplexed holograms in the master medium 710.
  • One variation for the system in Figure 7 is that the single collimating lens 710 is eliminated. Instead, a plurality of collimating optical elements are placed in front of the laser diodes 700. Each collimating optical element can be integrated with a laser diode 700 in a single package.

Abstract

Le système décrit ci-dessous permet de reproduire des informations holographiques multiplexées à partir d'un support original (100, 300, 400, 500, 600, 720) sur un support de reproduction (200, 310, 410, 510, 610, 730). Il lit simultanément les informations venant de tous les hologrammes originaux contenus dans le même support original et les enregistre sur le support de reproduction. La copie présente des distributions de phase et d'amplitude différentes du support original contenant une pluralité d'hologrammes multiplexés (420, 520), bien que la copie et l'original contiennent des informations holographiques identiques des objets originaux.
PCT/US1996/010410 1995-06-23 1996-06-21 Systeme et procede de copie d'hologrammes multiplexes WO1997001133A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AU63342/96A AU6334296A (en) 1995-06-23 1996-06-21 Multiplexed hologram copying system and method
EP96922483A EP0835479A4 (fr) 1995-06-23 1996-06-21 Systeme et procede de copie d'hologrammes multiplexes
JP9503883A JPH11515110A (ja) 1995-06-23 1996-06-21 複合ホログラム複写システム及び方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US47195P 1995-06-23 1995-06-23
US60/000,471 1995-06-23

Publications (1)

Publication Number Publication Date
WO1997001133A1 true WO1997001133A1 (fr) 1997-01-09

Family

ID=21691655

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1996/010410 WO1997001133A1 (fr) 1995-06-23 1996-06-21 Systeme et procede de copie d'hologrammes multiplexes

Country Status (6)

Country Link
EP (1) EP0835479A4 (fr)
JP (1) JPH11515110A (fr)
KR (1) KR19990028317A (fr)
AU (1) AU6334296A (fr)
CA (1) CA2225676A1 (fr)
WO (1) WO1997001133A1 (fr)

Cited By (50)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000016169A1 (fr) * 1998-09-10 2000-03-23 Eugen Pavel Dispositif, procede holographique de duplication de memoires holographiques et optiques, et copie de memoire ainsi obtenue
WO2001050190A1 (fr) * 2000-01-03 2001-07-12 Moiree Ltd Oy Procede de formation d'image sur un support
WO2003091809A1 (fr) * 2002-04-26 2003-11-06 Discovision Associates Reproduction rapide de dispositif de stockage diffractif pour production en serie
EP1477972A2 (fr) * 2003-04-30 2004-11-17 Daewoo Electronics Corporation Appareil et méthode d'enregistrement de données numériques dans un système d'enregistrement holographiqhe
WO2005066939A2 (fr) * 2003-12-30 2005-07-21 Aprilis, Inc. Copie de donnees sur un support holographique
DE19809402B4 (de) * 1997-08-04 2012-05-31 Bundesdruckerei Gmbh Verfahren und Vorrichtung zur Herstellung einer Kontaktkopie eines Hologramms
US8306376B2 (en) 2005-12-22 2012-11-06 Wi-Lan Inc. Method and apparatus for multiplexing optical information for recording and reproducing optical information over optical storage medium
WO2014100182A1 (fr) * 2012-12-19 2014-06-26 Microsoft Corporation Mosaïque d'hologrammes multiplex dans un dispositif d'affichage à guide d'ondes
DE19809403B4 (de) * 1997-08-05 2017-07-06 Bundesdruckerei Gmbh Verfahren zur Herstellung eines Hologramms mit einer maschinenlesbaren Information
US10089516B2 (en) 2013-07-31 2018-10-02 Digilens, Inc. Method and apparatus for contact image sensing
US10145533B2 (en) 2005-11-11 2018-12-04 Digilens, Inc. Compact holographic illumination device
US10156681B2 (en) 2015-02-12 2018-12-18 Digilens Inc. Waveguide grating device
US10185154B2 (en) 2011-04-07 2019-01-22 Digilens, Inc. Laser despeckler based on angular diversity
US10209517B2 (en) 2013-05-20 2019-02-19 Digilens, Inc. Holographic waveguide eye tracker
US10216061B2 (en) 2012-01-06 2019-02-26 Digilens, Inc. Contact image sensor using switchable bragg gratings
US10234696B2 (en) 2007-07-26 2019-03-19 Digilens, Inc. Optical apparatus for recording a holographic device and method of recording
US10241330B2 (en) 2014-09-19 2019-03-26 Digilens, Inc. Method and apparatus for generating input images for holographic waveguide displays
US10330777B2 (en) 2015-01-20 2019-06-25 Digilens Inc. Holographic waveguide lidar
US10359736B2 (en) 2014-08-08 2019-07-23 Digilens Inc. Method for holographic mastering and replication
US10423222B2 (en) 2014-09-26 2019-09-24 Digilens Inc. Holographic waveguide optical tracker
US10437051B2 (en) 2012-05-11 2019-10-08 Digilens Inc. Apparatus for eye tracking
US10437064B2 (en) 2015-01-12 2019-10-08 Digilens Inc. Environmentally isolated waveguide display
US10459145B2 (en) 2015-03-16 2019-10-29 Digilens Inc. Waveguide device incorporating a light pipe
US10545346B2 (en) 2017-01-05 2020-01-28 Digilens Inc. Wearable heads up displays
US10591756B2 (en) 2015-03-31 2020-03-17 Digilens Inc. Method and apparatus for contact image sensing
US10642058B2 (en) 2011-08-24 2020-05-05 Digilens Inc. Wearable data display
US10670876B2 (en) 2011-08-24 2020-06-02 Digilens Inc. Waveguide laser illuminator incorporating a despeckler
US10678053B2 (en) 2009-04-27 2020-06-09 Digilens Inc. Diffractive projection apparatus
US10690916B2 (en) 2015-10-05 2020-06-23 Digilens Inc. Apparatus for providing waveguide displays with two-dimensional pupil expansion
US10690851B2 (en) 2018-03-16 2020-06-23 Digilens Inc. Holographic waveguides incorporating birefringence control and methods for their fabrication
US10732569B2 (en) 2018-01-08 2020-08-04 Digilens Inc. Systems and methods for high-throughput recording of holographic gratings in waveguide cells
US10859768B2 (en) 2016-03-24 2020-12-08 Digilens Inc. Method and apparatus for providing a polarization selective holographic waveguide device
US10890707B2 (en) 2016-04-11 2021-01-12 Digilens Inc. Holographic waveguide apparatus for structured light projection
US20210026297A1 (en) * 2019-07-22 2021-01-28 Digilens Inc. Systems and Methods for High Volume Manufacturing of Waveguides
US10914950B2 (en) 2018-01-08 2021-02-09 Digilens Inc. Waveguide architectures and related methods of manufacturing
US10942430B2 (en) 2017-10-16 2021-03-09 Digilens Inc. Systems and methods for multiplying the image resolution of a pixelated display
US10983340B2 (en) 2016-02-04 2021-04-20 Digilens Inc. Holographic waveguide optical tracker
US11204540B2 (en) 2009-10-09 2021-12-21 Digilens Inc. Diffractive waveguide providing a retinal image
US11307432B2 (en) 2014-08-08 2022-04-19 Digilens Inc. Waveguide laser illuminator incorporating a Despeckler
US11378732B2 (en) 2019-03-12 2022-07-05 DigLens Inc. Holographic waveguide backlight and related methods of manufacturing
US11402801B2 (en) 2018-07-25 2022-08-02 Digilens Inc. Systems and methods for fabricating a multilayer optical structure
US11442222B2 (en) 2019-08-29 2022-09-13 Digilens Inc. Evacuated gratings and methods of manufacturing
US11448937B2 (en) 2012-11-16 2022-09-20 Digilens Inc. Transparent waveguide display for tiling a display having plural optical powers using overlapping and offset FOV tiles
US11460621B2 (en) 2012-04-25 2022-10-04 Rockwell Collins, Inc. Holographic wide angle display
US11480788B2 (en) 2015-01-12 2022-10-25 Digilens Inc. Light field displays incorporating holographic waveguides
US11513350B2 (en) 2016-12-02 2022-11-29 Digilens Inc. Waveguide device with uniform output illumination
US11543594B2 (en) 2019-02-15 2023-01-03 Digilens Inc. Methods and apparatuses for providing a holographic waveguide display using integrated gratings
US11681143B2 (en) 2019-07-29 2023-06-20 Digilens Inc. Methods and apparatus for multiplying the image resolution and field-of-view of a pixelated display
US11726332B2 (en) 2009-04-27 2023-08-15 Digilens Inc. Diffractive projection apparatus
US11747568B2 (en) 2019-06-07 2023-09-05 Digilens Inc. Waveguides incorporating transmissive and reflective gratings and related methods of manufacturing

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8786923B2 (en) * 2002-11-22 2014-07-22 Akonia Holographics, Llc Methods and systems for recording to holographic storage media
KR100682258B1 (ko) * 2005-06-30 2007-02-15 주식회사 대우일렉트로닉스 홀로그래픽 디스크용 복제 장치
JP5348419B2 (ja) * 2009-12-18 2013-11-20 大日本印刷株式会社 画面切替型ホログラム作製方法及びそれにより作製された画面切替型ホログラム
JP6960144B2 (ja) * 2017-04-11 2021-11-05 国立研究開発法人情報通信研究機構 ホログラム製造方法及びホログラム記録装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3752557A (en) * 1966-06-10 1973-08-14 Csf System of hologram reproduction
US3758186A (en) * 1966-11-30 1973-09-11 Battelle Development Corp Method of copying holograms
US5499118A (en) * 1994-08-31 1996-03-12 Hughes Aircraft Company System for copying multiple holograms

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3752557A (en) * 1966-06-10 1973-08-14 Csf System of hologram reproduction
US3758186A (en) * 1966-11-30 1973-09-11 Battelle Development Corp Method of copying holograms
US5499118A (en) * 1994-08-31 1996-03-12 Hughes Aircraft Company System for copying multiple holograms

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0835479A4 *

Cited By (80)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19809402B4 (de) * 1997-08-04 2012-05-31 Bundesdruckerei Gmbh Verfahren und Vorrichtung zur Herstellung einer Kontaktkopie eines Hologramms
DE19809403B4 (de) * 1997-08-05 2017-07-06 Bundesdruckerei Gmbh Verfahren zur Herstellung eines Hologramms mit einer maschinenlesbaren Information
WO2000016169A1 (fr) * 1998-09-10 2000-03-23 Eugen Pavel Dispositif, procede holographique de duplication de memoires holographiques et optiques, et copie de memoire ainsi obtenue
WO2001050190A1 (fr) * 2000-01-03 2001-07-12 Moiree Ltd Oy Procede de formation d'image sur un support
WO2003091809A1 (fr) * 2002-04-26 2003-11-06 Discovision Associates Reproduction rapide de dispositif de stockage diffractif pour production en serie
US7248556B2 (en) 2002-04-26 2007-07-24 Research Investment Network, Inc. Fast duplication of diffractive storage device for mass production
EP1477972A2 (fr) * 2003-04-30 2004-11-17 Daewoo Electronics Corporation Appareil et méthode d'enregistrement de données numériques dans un système d'enregistrement holographiqhe
EP1477972A3 (fr) * 2003-04-30 2006-05-10 Daewoo Electronics Corporation Appareil et méthode d'enregistrement de données numériques dans un système d'enregistrement holographiqhe
US7453611B2 (en) 2003-12-30 2008-11-18 Stx Aprilis, Inc. Replication of data to holographic medium using holographic master media
US7742210B2 (en) 2003-12-30 2010-06-22 Stx Aprilis, Inc. Replication of data to holographic medium using holographic master media
WO2005066939A3 (fr) * 2003-12-30 2005-11-17 Aprilis Inc Copie de donnees sur un support holographique
WO2005066939A2 (fr) * 2003-12-30 2005-07-21 Aprilis, Inc. Copie de donnees sur un support holographique
US10145533B2 (en) 2005-11-11 2018-12-04 Digilens, Inc. Compact holographic illumination device
US8306376B2 (en) 2005-12-22 2012-11-06 Wi-Lan Inc. Method and apparatus for multiplexing optical information for recording and reproducing optical information over optical storage medium
US10725312B2 (en) 2007-07-26 2020-07-28 Digilens Inc. Laser illumination device
US10234696B2 (en) 2007-07-26 2019-03-19 Digilens, Inc. Optical apparatus for recording a holographic device and method of recording
US11726332B2 (en) 2009-04-27 2023-08-15 Digilens Inc. Diffractive projection apparatus
US11175512B2 (en) 2009-04-27 2021-11-16 Digilens Inc. Diffractive projection apparatus
US10678053B2 (en) 2009-04-27 2020-06-09 Digilens Inc. Diffractive projection apparatus
US11204540B2 (en) 2009-10-09 2021-12-21 Digilens Inc. Diffractive waveguide providing a retinal image
US10185154B2 (en) 2011-04-07 2019-01-22 Digilens, Inc. Laser despeckler based on angular diversity
US11487131B2 (en) 2011-04-07 2022-11-01 Digilens Inc. Laser despeckler based on angular diversity
US11287666B2 (en) 2011-08-24 2022-03-29 Digilens, Inc. Wearable data display
US10670876B2 (en) 2011-08-24 2020-06-02 Digilens Inc. Waveguide laser illuminator incorporating a despeckler
US10642058B2 (en) 2011-08-24 2020-05-05 Digilens Inc. Wearable data display
US10216061B2 (en) 2012-01-06 2019-02-26 Digilens, Inc. Contact image sensor using switchable bragg gratings
US10459311B2 (en) 2012-01-06 2019-10-29 Digilens Inc. Contact image sensor using switchable Bragg gratings
US11460621B2 (en) 2012-04-25 2022-10-04 Rockwell Collins, Inc. Holographic wide angle display
US10437051B2 (en) 2012-05-11 2019-10-08 Digilens Inc. Apparatus for eye tracking
US11448937B2 (en) 2012-11-16 2022-09-20 Digilens Inc. Transparent waveguide display for tiling a display having plural optical powers using overlapping and offset FOV tiles
US10146053B2 (en) 2012-12-19 2018-12-04 Microsoft Technology Licensing, Llc Multiplexed hologram tiling in a waveguide display
CN105190407A (zh) * 2012-12-19 2015-12-23 微软技术许可有限责任公司 波导显示器中经复用全息图的小块化
WO2014100182A1 (fr) * 2012-12-19 2014-06-26 Microsoft Corporation Mosaïque d'hologrammes multiplex dans un dispositif d'affichage à guide d'ondes
US10209517B2 (en) 2013-05-20 2019-02-19 Digilens, Inc. Holographic waveguide eye tracker
US11662590B2 (en) 2013-05-20 2023-05-30 Digilens Inc. Holographic waveguide eye tracker
US10423813B2 (en) 2013-07-31 2019-09-24 Digilens Inc. Method and apparatus for contact image sensing
US10089516B2 (en) 2013-07-31 2018-10-02 Digilens, Inc. Method and apparatus for contact image sensing
US10359736B2 (en) 2014-08-08 2019-07-23 Digilens Inc. Method for holographic mastering and replication
US11307432B2 (en) 2014-08-08 2022-04-19 Digilens Inc. Waveguide laser illuminator incorporating a Despeckler
US11709373B2 (en) 2014-08-08 2023-07-25 Digilens Inc. Waveguide laser illuminator incorporating a despeckler
US11726323B2 (en) 2014-09-19 2023-08-15 Digilens Inc. Method and apparatus for generating input images for holographic waveguide displays
US10241330B2 (en) 2014-09-19 2019-03-26 Digilens, Inc. Method and apparatus for generating input images for holographic waveguide displays
US10423222B2 (en) 2014-09-26 2019-09-24 Digilens Inc. Holographic waveguide optical tracker
US10437064B2 (en) 2015-01-12 2019-10-08 Digilens Inc. Environmentally isolated waveguide display
US11726329B2 (en) 2015-01-12 2023-08-15 Digilens Inc. Environmentally isolated waveguide display
US11480788B2 (en) 2015-01-12 2022-10-25 Digilens Inc. Light field displays incorporating holographic waveguides
US11740472B2 (en) 2015-01-12 2023-08-29 Digilens Inc. Environmentally isolated waveguide display
US10330777B2 (en) 2015-01-20 2019-06-25 Digilens Inc. Holographic waveguide lidar
US11703645B2 (en) 2015-02-12 2023-07-18 Digilens Inc. Waveguide grating device
US10527797B2 (en) 2015-02-12 2020-01-07 Digilens Inc. Waveguide grating device
US10156681B2 (en) 2015-02-12 2018-12-18 Digilens Inc. Waveguide grating device
US10459145B2 (en) 2015-03-16 2019-10-29 Digilens Inc. Waveguide device incorporating a light pipe
US10591756B2 (en) 2015-03-31 2020-03-17 Digilens Inc. Method and apparatus for contact image sensing
US11281013B2 (en) 2015-10-05 2022-03-22 Digilens Inc. Apparatus for providing waveguide displays with two-dimensional pupil expansion
US10690916B2 (en) 2015-10-05 2020-06-23 Digilens Inc. Apparatus for providing waveguide displays with two-dimensional pupil expansion
US11754842B2 (en) 2015-10-05 2023-09-12 Digilens Inc. Apparatus for providing waveguide displays with two-dimensional pupil expansion
US10983340B2 (en) 2016-02-04 2021-04-20 Digilens Inc. Holographic waveguide optical tracker
US10859768B2 (en) 2016-03-24 2020-12-08 Digilens Inc. Method and apparatus for providing a polarization selective holographic waveguide device
US11604314B2 (en) 2016-03-24 2023-03-14 Digilens Inc. Method and apparatus for providing a polarization selective holographic waveguide device
US10890707B2 (en) 2016-04-11 2021-01-12 Digilens Inc. Holographic waveguide apparatus for structured light projection
US11513350B2 (en) 2016-12-02 2022-11-29 Digilens Inc. Waveguide device with uniform output illumination
US11586046B2 (en) 2017-01-05 2023-02-21 Digilens Inc. Wearable heads up displays
US11194162B2 (en) 2017-01-05 2021-12-07 Digilens Inc. Wearable heads up displays
US10545346B2 (en) 2017-01-05 2020-01-28 Digilens Inc. Wearable heads up displays
US10942430B2 (en) 2017-10-16 2021-03-09 Digilens Inc. Systems and methods for multiplying the image resolution of a pixelated display
US10732569B2 (en) 2018-01-08 2020-08-04 Digilens Inc. Systems and methods for high-throughput recording of holographic gratings in waveguide cells
US11703799B2 (en) 2018-01-08 2023-07-18 Digilens Inc. Systems and methods for high-throughput recording of holographic gratings in waveguide cells
US10914950B2 (en) 2018-01-08 2021-02-09 Digilens Inc. Waveguide architectures and related methods of manufacturing
US10690851B2 (en) 2018-03-16 2020-06-23 Digilens Inc. Holographic waveguides incorporating birefringence control and methods for their fabrication
US11726261B2 (en) 2018-03-16 2023-08-15 Digilens Inc. Holographic waveguides incorporating birefringence control and methods for their fabrication
US11150408B2 (en) 2018-03-16 2021-10-19 Digilens Inc. Holographic waveguides incorporating birefringence control and methods for their fabrication
US11402801B2 (en) 2018-07-25 2022-08-02 Digilens Inc. Systems and methods for fabricating a multilayer optical structure
US11543594B2 (en) 2019-02-15 2023-01-03 Digilens Inc. Methods and apparatuses for providing a holographic waveguide display using integrated gratings
US11378732B2 (en) 2019-03-12 2022-07-05 DigLens Inc. Holographic waveguide backlight and related methods of manufacturing
US11747568B2 (en) 2019-06-07 2023-09-05 Digilens Inc. Waveguides incorporating transmissive and reflective gratings and related methods of manufacturing
US20210026297A1 (en) * 2019-07-22 2021-01-28 Digilens Inc. Systems and Methods for High Volume Manufacturing of Waveguides
US11681143B2 (en) 2019-07-29 2023-06-20 Digilens Inc. Methods and apparatus for multiplying the image resolution and field-of-view of a pixelated display
US11592614B2 (en) 2019-08-29 2023-02-28 Digilens Inc. Evacuated gratings and methods of manufacturing
US11442222B2 (en) 2019-08-29 2022-09-13 Digilens Inc. Evacuated gratings and methods of manufacturing
US11899238B2 (en) 2019-08-29 2024-02-13 Digilens Inc. Evacuated gratings and methods of manufacturing

Also Published As

Publication number Publication date
EP0835479A4 (fr) 1999-07-21
CA2225676A1 (fr) 1997-01-09
EP0835479A1 (fr) 1998-04-15
JPH11515110A (ja) 1999-12-21
AU6334296A (en) 1997-01-22
KR19990028317A (ko) 1999-04-15

Similar Documents

Publication Publication Date Title
EP0835479A1 (fr) Systeme et procede de copie d'hologrammes multiplexes
US7742210B2 (en) Replication of data to holographic medium using holographic master media
JP5466833B2 (ja) ページに基づくホログラフィー記録および読み出しを実行する方法
JP6053891B2 (ja) ホログラフィックストレージ媒体に記録する方法
US6538776B2 (en) Self-referenced holographic storage
US8199388B2 (en) Holographic recording system having a relay system
KR100477783B1 (ko) 홀로그래피프로세스및홀로그래피어레이의복제프로세스
US6018402A (en) Apparatus and method for phase-encoding off-axis spatial light modulators within holographic data systems
US20010035990A1 (en) Multiplexed hologram copying system and method
US6762865B1 (en) Self-referenced holography using diffusive element
KR100354798B1 (ko) 위상상관다중화홀로그래픽메모리시스템및그에이용되는장치
US7088482B2 (en) Holographic recording techniques using first and second portions of a spatial light modulator
US7187481B1 (en) System and method for providing gain and thresholding to a holographic data parallel recording and replication system incorporating independent angular address assignment
CN1954370A (zh) 全息图母片制作和复制
Sincerbox History and physical principles
US7088481B2 (en) Holographic recording techniques using reference zone of spatial light modulator
JPH05181404A (ja) ホログラム記録方法および装置
Wilson et al. Introduction to Holographic Data Recording
KR100727777B1 (ko) 전반사를 이용한 광정보 복제방법 및 복제장치
Barbastathis et al. Imaging and Storage with Spherical-Reference Volume Holograms
PSALTIS et al. 3-Dimensional Holographic Disks
JP2010535358A (ja) Ｈｒｏｍ複製方法、装置またはシステム、同方法、装置またはシステムで使用された物品および同方法、装置またはシステムで作成された物品
Kim et al. Double side hologram reconstruction for digital holographic data storage using phase conjugated reference beam
KR20060017371A (ko) 홀로그래픽 디지털 데이터 시스템의 데이터 복제 장치

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IL IS JP KE KG KP KR KZ LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TR TT UA UG US UZ VN AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE LS MW SD SZ UG AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
ENP Entry into the national phase

Ref document number: 2225676

Country of ref document: CA

Ref country code: CA

Ref document number: 2225676

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 1019970709632

Country of ref document: KR

ENP Entry into the national phase

Ref country code: JP

Ref document number: 1997 503883

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 1996922483

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 08981764

Country of ref document: US

WWP Wipo information: published in national office

Ref document number: 1996922483

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWP Wipo information: published in national office

Ref document number: 1019970709632

Country of ref document: KR

WWW Wipo information: withdrawn in national office

Ref document number: 1019970709632

Country of ref document: KR

WWW Wipo information: withdrawn in national office

Ref document number: 1996922483

Country of ref document: EP