CN101779240A - Holographic information storage medium, and method and apparatus for recording/reproducing holographic information using the same - Google Patents

Holographic information storage medium, and method and apparatus for recording/reproducing holographic information using the same Download PDF

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Publication number
CN101779240A
CN101779240A CN200880103156A CN200880103156A CN101779240A CN 101779240 A CN101779240 A CN 101779240A CN 200880103156 A CN200880103156 A CN 200880103156A CN 200880103156 A CN200880103156 A CN 200880103156A CN 101779240 A CN101779240 A CN 101779240A
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CN
China
Prior art keywords
light beam
polarization direction
recording layer
hologram recording
information
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Pending
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CN200880103156A
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Chinese (zh)
Inventor
郑泽成
裴在喆
郑文一
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Samsung Electronics Co Ltd
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Samsung Electronics Co Ltd
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Application filed by Samsung Electronics Co Ltd filed Critical Samsung Electronics Co Ltd
Priority claimed from PCT/KR2008/002847 external-priority patent/WO2009022788A1/en
Publication of CN101779240A publication Critical patent/CN101779240A/en
Pending legal-status Critical Current

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    • 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
    • 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
    • G11B7/24—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
    • G11B7/24062—Reflective layers
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B2220/00—Record carriers by type
    • G11B2220/20—Disc-shaped record carriers
    • G11B2220/25—Disc-shaped record carriers characterised in that the disc is based on a specific recording technology
    • G11B2220/2504—Holographic discs; Holographic digital data storage [HDDS]

Abstract

A holographic storage medium includes a substrate; a cover layer to receive a first circular polarization beam having a first polarization direction and a second circular polarization beam having a second polarization direction orthogonal to the first polarization direction; a polarization beam splitting/reflective layer disposed between the substrate and the cover layer to reflect the first beam while maintaining the first polarization direction of the first beam, and to transmit the second beam; and a holographic recording layer disposed between the polarization beam splitting/reflective layer and the cover layer to record information as an interference pattern formed in the holographic layer by the first beam reflected by the polarization beam splitting/reflective layer and the second beam received by the cover layer.

Description

Holographic information storage medium and utilize the method and apparatus of its recording/reproducing holographic information
Technical field
The method and apparatus that many aspects of the present invention relate to a kind of holographic information storage medium and utilize this holographic information storage medium recording/reproducing holographic information, more particularly, relate to one-sided type holographic information storage medium that a kind of signal beams and the reference beam same surface by holographic information storage medium enters and the method and apparatus that utilizes described one-sided type holographic information storage medium recording/reproducing holographic information, the noise when described one-sided type holographic information storage medium reduces information reproduction.
Background technology
Recently, utilize the information storage technology of hologram to cause a lot of attentions.Utilize the information storage means of hologram that the form of information with optical interference pattern is stored in the polymeric material or mineral crystal of sensitization.Utilize two laser beam to form optical interference pattern, described two laser beam interfere with each other to generate interference pattern.That is, cause chemistry or physical change in the sensitization storage medium at the interference pattern that when the reference beam of different propagated and signal beams interfere with each other, forms, thus recorded information.For interference pattern information reproduction from record, the reference beam that be used to reproduce similar to the reference beam that is used to write down is transmitted into the interference pattern that is recorded on the storage medium, interference pattern carries out diffraction with the restoring signal light beam to reference beam, thus information reproduction.
The holographic information memory technology comprises body holography method and little holography method, and the body holography method is unit record/information reproduction with the page or leaf by utilizing the body holography, little holography method by utilize microholography with digital ratio specially for unit record/information reproduction.The advantage of body holography method is to handle bulk information simultaneously.Yet the body holography method has such shortcoming: owing to need very accurately to regulate optical system, so be difficult to the information-storing device that commercialization becomes ordinary consumer.
In microholography, the light beam of two focusing is interfered with each other at the focus place on storage medium, move in the plane of storage medium by making such interference pattern, write down a plurality of interference patterns to form information faces.By depth direction stacked a plurality of information faces in hologram recording layer, with three-dimensional (3D) mode recorded information along storage medium.
If signal beams and reference beam are incident on respectively on two relative surfaces of information storage medium to carry out record, then must be provided for signal beams in the relative both sides of information storage medium respectively and be used for the optical system of reference beam, thereby increase the size of whole optical system.In order to overcome this problem, proposed signal beams and reference beam are transmitted into the same lip-deep one-sided recording/reproducing method of information storage medium.In this method, signal beams and reference beam are focused on the focus in the included hologram recording layer of information storage medium, and with the form recorded information of the interference pattern that is formed on the focus place.Can be by reference beam being transmitted into the information that hologram recording layer reproduces record.
Summary of the invention
Technical matters
Yet the shortcoming of one-sided recording/reproducing method is: the noise that is caused by reflected light.In traditional optical information recorder/reproducting method,, can remove noise by increasing the distance between hologram recording layer and the reflection horizon and the reflected light that is incident on the photoelectric detector being defocused.Yet because the characteristic of hologram, the amplitude of reproducing signal is very little, and the method that therefore is difficult to remove noise by the distance between increase hologram recording layer and the reflection horizon is applied to the holographic recording storage medium.The reflectivity of hologram, promptly diffraction efficiency changes according to the thickness of the hologram of record and the variations in refractive index that records in the information storage medium of hologram.At this on the one hand, when local recorded hologram, as under the situation of microhologram, the reflectivity of microhologram is very little.Usually, the variations in refractive index that typically is used to form the photopolymer (photopolymer) of hologram recording layer is about 0.01.In this case, when the optical system that by numerical aperture is 0.85 write down microhologram, the reflectivity of microhologram was 1% or littler.In addition, when in order to increase recording capacity in a plurality of information faces during recorded information, reflectivity further reduces.Usually, well known to a person skilled in the art to be square being inversely proportional to of the quantity of reflectivity and hologram recording layer.For example, when 20 of uses or more hologram recording layers, reflectivity is extremely little, is 0.01% or littler.Because the such characteristic of hologram, the distance between hologram recording layer and reflection horizon reduces, so that during the noise that reduces to be caused by reflected light, signal beams and the aberration between the reference beam that must compensation increase.In addition, since optical system to tilt sensitive, so be difficult to construct described optical system.
Technical scheme
According to many aspects of the present invention, utilize one-sided recording method to record the holographic information storage medium of information and record information to described holographic information storage medium and/or can prevent signal quality because the caused noise of reflected light that the information on being recorded in holographic information storage medium generates when reproduced and variation from the method and apparatus of described holographic information storage medium information reproduction.
According to an aspect of the present invention, a kind of holographic information storage medium comprises: substrate; Overlayer receives first circularly polarized light beam with first polarization direction and second circularly polarized light beam with second polarization direction, wherein, and second polarization direction and the first polarization direction quadrature; Light beam is cut apart/reflection horizon, is arranged between substrate and the overlayer, be used in first polarization direction that keeps first light beam, reflecting first light beam, and transmission second light beam; Hologram recording layer, be arranged on light beam to cut apart/reflection horizon and overlayer between, be used for information is recorded as by being polarized light beam and cut apart/interference pattern that first light beam of reflective layer reflects and second light beam that the lining cap rock receives form.
According to an aspect of the present invention, providing a kind of is used to record the information on the holographic information storage medium and/or from the holographic information recording/reproducer of holographic information storage medium information reproduction.Described holographic information storage medium comprises: substrate; Overlayer; Light beam is cut apart/reflection horizon, be arranged between substrate and the overlayer, be used to reflect first polarization direction that first circularly polarized light beam with first polarization direction keeps first light beam simultaneously, and transmission has second circularly polarized light beam with second polarization direction of the first polarization direction quadrature; Hologram recording layer, be arranged on light beam to cut apart/reflection horizon and overlayer between.Described equipment comprises: optical pickup apparatus, generation has first circularly polarized light beam of first polarization direction and has second circularly polarized light beam with second polarization direction of the first circular polarization quadrature, and launch first light beam and second light beam is incident on the overlayer of holographic information storage medium first light beam and second light beam, make the light beam of winning be polarized light beam and cut apart/reflective layer reflects; Be polarized light beam to cut apart/first light beam of reflective layer reflects and be incident on the focus place of supratectal second light beam in hologram recording layer and form interference pattern; Hologram recording layer is recorded as interference pattern at the focus place with information.
According to an aspect of the present invention, providing a kind of is used to record the information on the holographic information storage medium and/or from the holographic information recording/reproducer of holographic information storage medium information reproduction.Described holographic information storage medium comprises: substrate; Overlayer; Light beam is cut apart/reflection horizon, be arranged between substrate and the overlayer, be used to reflect first polarization direction that first circularly polarized light beam with first polarization direction keeps first light beam simultaneously, and transmission has second circularly polarized light beam with second polarization direction of the first polarization direction quadrature; Hologram recording layer, be arranged on light beam to cut apart/reflection horizon and overlayer between, be used for cutting apart/first light beam of reflective layer reflects and the interference pattern that second light beam is recorded as information at the focus place that is formed on hologram recording layer by being polarized light beam.Described equipment comprises: optical pickup apparatus, generation has second circularly polarized light beam with second polarization direction of the first polarization direction quadrature, and launch second light beam second light beam is incident on the overlayer of holographic information storage medium, make second light beam partly be reflected the folded light beam that has first polarization direction with formation by the interference pattern in the hologram recording layer at the focus place with second polarization direction, by the interference pattern in the hologram recording layer partly transmission have the transmitted light beam of second polarization direction with formation; Folded light beam is incident on the optical pickup apparatus; Transmitted light beam passes light beam to be cut apart/reflection horizon; Light beam cuts apart/reflection horizon stop pass light beam at transmitted light beam and cut apart/reflection horizon after any reflected light of reflection generation by transmitted light beam be incident on the optical pickup apparatus.
According to an aspect of the present invention, providing a kind of records the information on the holographic information storage medium and/or from the method for holographic information storage medium information reproduction.Described holographic information storage medium comprises: substrate; Overlayer; Light beam is cut apart/reflection horizon, be arranged between substrate and the overlayer, be used to reflect first polarization direction that first circularly polarized light beam with first polarization direction keeps first light beam simultaneously, and transmission has second circularly polarized light beam with second polarization direction of the first polarization direction quadrature; Hologram recording layer, be arranged on light beam to cut apart/reflection horizon and overlayer between.Described method comprises: generate first circularly polarized light beam with first polarization direction and have second circularly polarized light beam with second polarization direction of the first polarization direction quadrature; To the overlayer of holographic information storage medium, make win light beam and second light beam pass overlayer first light beam and second beam emissions; Make to be polarized light beam and to cut apart/reflective layer reflects and first light beam with first polarization direction focus on the focus place in the holographic recording medium; Make second light beam that passes overlayer and have second polarization direction focus on focus place in the hologram recording layer, make win light beam and second beam interference near focus, forming interference pattern, thereby information is registered as the interference pattern in the hologram recording layer.
Other aspect of the present invention and/or advantage will partly be set forth by following description, and partly will obviously, perhaps can be to understand by the practice of the present invention according to described description.
Beneficial effect
Therefore, according to many aspects of the present invention, holographic information storage medium and record information to described holographic information storage medium and/or can prevent signal quality because the caused noise of reflected light that the information on being recorded in holographic information storage medium generates when reproduced and variation from the method and apparatus of described holographic information storage medium information reproduction, thus signal quality improved.
Description of drawings
To the detailed description and the claim of exemplary embodiment, better understanding of the present invention will become obviously below reading in conjunction with the drawings, and wherein, described accompanying drawing, instructions and claim form a disclosed part of the present invention.Disclose exemplary embodiment of the present invention although disclosing shown in following the writing concentrates on, what should be expressly understood that is that this only is schematic and exemplary approach, the invention is not restricted to this.The spirit and scope of the present invention only are defined by the claims.Provide brief description of drawings below, wherein:
Fig. 1 is the sectional view of holographic information storage medium according to an exemplary embodiment of the present invention;
Fig. 2 is that light beam is cut apart/curve map of the optical characteristics in reflection horizon according to an exemplary embodiment of the present invention;
Fig. 3 illustrates and is used for according to an exemplary embodiment of the present invention signal beams and reference beam are transmitted into optical configuration on the holographic information storage medium of Fig. 1;
Fig. 4 is the enlarged image of the A part of the interference pattern that formed by signal beams and reference beam of the demonstration of Fig. 3;
Fig. 5 illustrates the signal beams on the holographic information storage medium that is incident on Fig. 1 according to an exemplary embodiment of the present invention and the polarization state of reference beam;
Fig. 6 illustrates the polarization state of the reconstruction beam on the holographic information storage medium that is incident on Fig. 1 according to an exemplary embodiment of the present invention;
To be the noise that generated by the noise light beam L3n of Fig. 6 cut apart/curve map of distance between the reflection horizon information faces and light beam Fig. 7;
Fig. 8 to Figure 11 is the sectional view of holographic information storage medium according to an exemplary embodiment of the present invention;
Figure 12 illustrates the optical configuration according to the holographic information recording/reproducer of the embodiment of the invention;
Figure 13 is the sectional view of punctured element according to an exemplary embodiment of the present invention;
Figure 14 illustrates according to an exemplary embodiment of the present invention and stops the situation that defocuses the noise light beam by punctured element.
Embodiment
Now detailed description is illustrated in the exemplary embodiment of the present invention in the accompanying drawing, in the accompanying drawings, identical label is represented identical parts all the time, and for clarity, the thickness in layer and zone can be by exaggerative.Exemplary embodiment is described with reference to the accompanying drawings to explain the present invention.
Fig. 1 is the sectional view of holographic information storage medium 100 according to an exemplary embodiment of the present invention.
With reference to Fig. 1, holographic information storage medium 100 comprises according to the stacked substrate 110 of sequence shown in Figure 1, servo layer 120, cushion 130, light beam and cutting apart/reflection horizon 140, wall 150, hologram recording layer 160 and overlayer 170.
Substrate 110 is support members of the shape (as dish type) that is provided for keeping holographic information storage medium 100, and can be formed by polycarbonate resin (polycarbonate resin), acryl resin (acrylicresin) etc.
Overlayer 170 protection hologram recording layers 160, and when hologram recording layer 160 be not the shape of maintenance holographic information storage medium 100 when forming by solid material.Can on overlayer 170, be formed for preventing the antireflection layer (not shown) of the surface reflection of light lining cap rock 170.
Hologram recording layer 160 is formed as photopolymer and thermoplastic material by photosensitive material, and described photosensitive material is refraction index changing when absorbing light.Usually, the light intensity of the refractive index of photosensitive material and absorption changes pro rata.Photosensitive material can have such nonlinear characteristic: photosensitive material has predetermined threshold aspect light intensity, and only intensity is made response above the light of described threshold value.In order to increase recording density, can form different interference patterns in different focal positions by depth direction along hologram recording layer 160, come stacked a plurality of different interference patterns in hologram recording layer 160.Therefore, have nonlinear characteristic if be used to form the material of hologram recording layer 160, then the distance along with the distance focal position increases, and the amplitude of interference pattern reduces fast, therefore can carry out intensive multilayer record.
Wall 150 is to be used to keep hologram recording layer 160 and light beam to cut apart/layer of distance between the reflection horizon 140, cut apart when being polarized light beam/signal beams of reflection horizon 140 reflection focuses on focal point F (with reference to Fig. 3) in the hologram recording layer 160 when going up, and wall 150 keeps light beams to cut apart/distance between the focal point F of reflection horizon 140 and executive logging.The thickness of wall 150 can change according to the characteristic of hologram recording layer 160, and wall 150 forms thickness in 0 to 100 mu m range.Similarly, cut apart/distance between reflection horizon 140 and the focal point F, when information reproduction, can reduce to cut apart/noise that light that reflection horizon 140 is reflected causes by light beam by keeping light beam.Detailed relation between below detailed interpretation interval layer 150 and noise being reduced.Yet, need in all embodiment of the present invention, not include wall 150, can use to keep light beam to cut apart/alternate manner of distance between reflection horizon 140 and the focal point F.For example, the part that is not used for recorded information of hologram recording layer 160 can replace wall 150.Light beam cuts apart/and reflection horizon 140 forms by the material of reflection first circularly polarized light beam and transmission second circularly polarized light beam, and described first circularly polarized light beam and second circularly polarized light beam have orthogonal polarization direction separately.In addition, light beam is cut apart/reflection horizon 140 reflection circle light beam in the polarization direction of first circularly polarized light beam that keeps reflection.To cut apart with light beam/reflection horizon 140 reflection Left-hand circular polarization light beam and transmission right-hand circular polarization light beams, and the situation that the Left-hand circular polarization light beam of reflection is maintained at the Left-hand circular polarization state is that example is described.Light beam cuts apart/and reflection horizon 140 can be formed by the cholesteric liquid crystal in the liquid crystal film that can be in liquid crystal state or sclerosis attitude.Cholesteric liquid crystal has such structure: wherein, the director axle of liquid crystal molecule twists according to spiral way.The result of this structure is that the cholesteric liquid crystal reflection is along the circularly polarized light beam of the direction polarization of described spiral, the circularly polarized light beam of the direction polarization that the transmission edge is relative with the direction of described spiral.Therefore, two kinds of circularly polarized light beams of polarization direction quadrature can be separated, and the state of the circularly polarized light beam of reflection can be maintained at the circular polarization state.
Fig. 2 is that light beam is cut apart/curve map of the optical characteristics in reflection horizon 140 according to an exemplary embodiment of the present invention.With reference to Fig. 2, transverse axis is to cut apart/the polarisation of light angle 0 of reflection horizon 140 transmissions by light beam, and Z-axis is to be incident on light beam and to cut apart/optical transmission rate on the reflection horizon 140.As can be seen, the R circularly polarized light beam is by transmission fully, but the L circularly polarized light beam is not almost completely by transmission.Constitute light beam at cholesteric liquid crystal to cut apart/situation in reflection horizon 140 under, can control the wavelength of the R circularly polarized light beam of transmission according to spiralization cycle.In addition, light beam cut apart/reflection horizon 140 can have such rhythmo structure: wherein, a plurality of cholesteric liquid crystal layer are stacked, so that the liquid crystal molecule of cholesteric liquid crystal layer has different spiralization cycles.In this case, the quantity of spiralization cycle by controlling stacked cholesteric liquid crystal layer and stacked cholesteric liquid crystal layer, by transmission or reflection, and the light with other wavelength is by transmission according to the polarisation of light direction for the light with predetermined wavelength.In current exemplary embodiment owing to cut apart/servo layer 120 is set below the reflection horizon 140 at light beam, so signal beams/reference beam according to the polarization direction of signal beams and reference beam by transmission/reflection, and servo beam is by transmission.
Cushion 130 between light beam cut apart/reflection horizon 140 and servo layer 120 between, and can form by the material that transparent material or absorption have the light of the wavelength that is used for the recoding/reproduction signal.Cushion 130 is set to fill and is formed on being used on the servo layer 120 and represents the servo pattern of servo-information so that light beam cut apart/reflection horizon 140 can form flatness layer.
Servo layer 120 is the layers with servo-information, servo layer 120 reflection servo beam.In current exemplary embodiment, the wavelength of servo beam is different from the light wavelength that is used for recoding/reproduction information.In addition, cushion 130, the light beam that is arranged on servo layer 120 tops cut apart/reflection horizon 140, wall 150, hologram recording layer 160 and overlayer 170 be designed to the transmission servo beam.
With reference to Fig. 3 to Fig. 5, the method on the holographic information storage medium 100 that records the information in Fig. 1 according to an exemplary embodiment of the present invention is described below.
Fig. 3 illustrates and is used for according to an exemplary embodiment of the present invention signal beams L1 and reference beam L2 are transmitted into optical configuration on the holographic information storage medium 100 of Fig. 1.Fig. 4 is the enlarged image of the A part of the interference pattern that formed by signal beams L1 and reference beam L2 of the demonstration of Fig. 3.Fig. 5 illustrates signal beams L1 on the holographic information storage medium 100 that is incident on Fig. 1 according to an exemplary embodiment of the present invention and the polarization state of reference beam L2.
With reference to Fig. 3, signal beams L1 and reference beam L2 are incident on the holographic information storage medium 100 through object lens 280.Signal beams L1 is polarized light beam to be cut apart/reflection horizon 140 reflection, and be focused on the focal point F in the hologram recording layer 160.Reference beam L2 is incident on the overlayer 170, and is focused on the focal point F.Because the luminous point of signal beams L1 and reference beam L2 is overlapping at the focal point F place, so form interference pattern.Because the shape of interference pattern changes according to the modulation condition of signal beams L1 or the modulation condition of signal beams L1 and reference beam L2, so can utilize the interference pattern recorded information.Fig. 4 is the enlarged image of focal point F that comprises signal beams L1 and reference beam L2 shown in Figure 3 and the A that shows interference pattern part.Interference pattern is recorded on the identical plane along track, thereby forms the information faces 165 of individual layer in hologram recording layer 160.Along with focal point F changes along the depth direction of hologram recording layer 160, a plurality of information faces 165 is stacked, thereby can carry out the multilayer record.Holographic information storage medium 100 according to current exemplary embodiment uses the microholography method that comprises single bit of information in the interference pattern at each focal point F place, but the invention is not restricted to such configuration.For example, can adopt body holography method, in body holography method, when focal point F is overlapping, form interference pattern at the luminous point of signal beams L1 and reference beam L2, thereby write down bulk information simultaneously with three dimensional constitution.
With reference to Fig. 5, the process of the formation interference pattern of considering polarization is described below.With reference to Fig. 5, comprise quarter-wave plate 285 and object lens 280 according to the holographic information recording/reproducer of current exemplary embodiment.Signal beams L1 and reference beam L2 with different linear polarizations are incident on the quarter-wave plate 285.For example, signal beams L1 is incident on the quarter-wave plate 285 with the S linear polarization state, and reference beam L2 is incident on the quarter-wave plate 285 with the P linear polarization state.Quarter-wave plate 285 is to be used for optical element that linear polarization is changed into circular polarization and circular polarization changed into linear polarization.Along with signal beams L1 passes quarter-wave plate 285, the polarization state of signal beams L1 is changed and is Left-hand circular polarization L.Along with reference beam L2 passes quarter-wave plate 285, the polarization state of reference beam L2 is changed and is right-hand circular polarization R.Signal beams L1 with Left-hand circular polarization L is polarized light beam to be cut apart/reflection horizon 140 reflection, and wherein, light beam cuts apart/and reflection horizon 140 keeps the Left-hand circular polarization L among the signal beams L1 of reflection.Signal beams L1 with reflection of Left-hand circular polarization L focuses on the information faces 165.Reference beam L2 with right-hand circular polarization R focuses on the information faces 165, passes light beam then and cuts apart/reflection horizon 140.Because the signal beams L1 and the reference beam L2 of the reflection of meeting on information faces 165 propagate in opposite direction, and have opposite circular polarization, so the electric field intensity of the signal beams L1 of reflection and the electric field intensity of reference beam L2 rotate along equidirectional.Therefore, generate interference pattern on information faces 165, interference pattern causes the information record in the hologram recording layer 160 that is formed by photosensitive material.
Pass light beam to cut apart/the reference beam L2 with right-hand circular polarization R in reflection horizon 140 can be by servo layer 120 reflections such as grade.Yet, owing to only changed its direction of propagation by the reference beam L2 of reflections such as servo layer 120, and the sense of rotation of its electric field intensity remains unchanged, so be in Left-hand circular polarization L state by the reference beam L2 of reflections such as servo layer 120.Therefore, reference beam L2 can not return and pass light beam and cut apart/reflection horizon 140.
In the above description, light beam L1 is described to signal beams, and light beam L2 is described to reference beam.Yet light beam L1 can be a reference beam, and light beam L2 can be a signal beams.
With reference to Fig. 6 and Fig. 7, the method for reproducing the information on the holographic information storage medium 100 that is recorded in Fig. 1 according to an exemplary embodiment of the present invention is described below.
Fig. 6 illustrates the polarization state of the reconstruction beam on the holographic information storage medium 100 that is incident on Fig. 1 according to an exemplary embodiment of the present invention.To be the noise that generated by the noise light beam L3n of Fig. 6 cut apart/curve map of distance between the reflection horizon 140 information faces 165 and light beam Fig. 7, wherein, among Fig. 7 described distance table is shown " distance in reflection horizon ".
With reference to Fig. 6, the polarization direction reconstruction beam identical with the polarization direction of reference beam is launched on the holographic information storage medium 100, so that information reproduction.That is, the incident reconstruction beam L3i with P polarization passes quarter-wave plate 285, and is changed and is right-hand circular polarization R.Then, the incident reconstruction beam L3i with right-hand circular polarization R passes object lens 280, and is incident on the holographic information storage medium 100.For information faces 165, the light beam that is incident on the information faces 165 is called as incident reconstruction beam L3i, is called as reconstruction by reflection light beam L3r by information faces 165 beam reflected, and transmission is called as transmission reconstruction beam L3t by the light beam of information faces 165.Have right-hand circular polarization R incident reconstruction beam L3i a part by information faces 165 diffraction that recorded information by interference pattern (promptly, reflection), and propagate as reconstruction by reflection light beam L3r and to get back to object lens 280, information faces 165 is passed through in a part of transmission with incident reconstruction beam L3i of right-hand circular polarization R, and cuts apart/reflection horizon 140 propagation towards light beam.Because the reconstruction by reflection light beam L3r that is reflected by information faces 165 only is changed its direction of propagation, and the sense of rotation of its electric field intensity remains unchanged, so reconstruction by reflection light beam L3r is in Left-hand circular polarization L state.Because the transmission reconstruction beam L3t by information faces 165 is in right-hand circular polarization R state from incident reconstruction beam L3i transmission with right-hand circular polarization R, cuts apart/reflection horizon 140 so transmission reconstruction beam L3t passes light beam.Transmission reconstruction beam L3t can be become the transmission reconstruction beam L3t ' of reflection by reflections such as servo layers 120.Yet owing to the transmission reconstruction beam L3t ' of reflection only is changed its direction of propagation, and the sense of rotation of its electric field intensity remains unchanged, so be in Left-hand circular polarization L state by the transmission reconstruction beam L3t ' of the reflection of reflections such as servo layer 120.Therefore, the transmission reconstruction beam L3t ' of reflection can not return and pass light beam and cut apart/reflection horizon 140.If the reflection transmission reconstruction beam L3t ' pass information faces 165, thereby incident return on the object lens 280, then with respect to the reproducing signal that is included among the reconstruction by reflection light beam L3r, the transmission reconstruction beam L3t ' of reflection can facilitate catoptrical noise light beam L3n.Yet, according to current exemplary embodiment, pass light beam and cut apart/reflection horizon 140 because the transmission reconstruction beam L3t ' of reflection can not return, thus the noise light beam L3n that causes by reflected light can be reduced, thus improve signal quality.Traditional servo layer is designed to reflection and transmission reconstruction beam L3t not, so that reduce noise light beam L3n.Yet according to the present invention, even servo layer 120 grades become the transmission reconstruction beam L3t ' of reflection with transmission reconstruction beam L3t reflection, the transmission reconstruction beam L3t ' of reflection can not return and pass light beam and cut apart/reflection horizon 140.Therefore, because servo layer 120 required performances reduce, so compare with the situation of using traditional servo layer, easier manufacturing is according to the holographic information storage medium 100 of current exemplary embodiment.
In the superincumbent description, the transmission reconstruction beam L3t that supposes to have right-hand circular polarization R passes light beam to be cut apart/reflection horizon 140, does not cut apart/reflection horizon 140 reflections and be not polarized light beam.Yet in fact, the part with transmission reconstruction beam L3t of right-hand circular polarization R can be polarized light beam to be cut apart/reflection horizon 140 reflections.In this case, because only the incident reconstruction beam L3i with right-hand circular polarization R of very little number percent is become reconstruction by reflection light beam L3r by information faces 165 reflection, so be attributable to be polarized light beam and cut apart/the noise light beam L3n component of the transmission reconstruction beam L3t that reflection horizon 140 is partly reflected can cause problem.Yet, can cut apart by information faces 165 and light beam that abundant increase records information/distance between the reflection horizon 140, reduce to be attributable to be polarized light beam to cut apart/the noise light beam L3n component of the transmission reconstruction beam L3t that reflection horizon 140 is partly reflected.
Fig. 7 is cut apart/curve map of distance between the reflection horizon 140 information faces 165 and light beam by carrying out noise that the noise light beam L3n by Fig. 6 that emulation obtains generates." distance in reflection horizon " among Fig. 7 be light beam cut apart/reflection horizon 140 and physical record have the distance between the information faces 165 of information.In described emulation, suppose incident reconstruction beam L3i by information faces 165 with the reflection of about 0.0135% reflectivity, to form reconstruction by reflection light beam L3r, the transmission reconstruction beam L3t that suppose to have right-hand circular polarization R is polarized light beam to be cut apart/and reflection horizon 140 is reflected with about 1% noise reflectivity.Along with information faces 165 and light beam cut apart/distance between the reflection horizon 140 increases, focus on transmission reconstruction beam L3t on the information faces 165 and become and cut apart at light beam/more and more defocus on the reflection horizon 140.Therefore, be attributable to be polarized light beam to cut apart/the noise light beam L3n component of the transmission reconstruction beam L3t of reflection horizon 140 reflection reduces.With reference to Fig. 7, when information faces 165 and light beam cut apart/distance between the reflection horizon 140 is 40 μ m or when bigger, noise-signal (N/S) is than less than 2.5% as can be seen.Under the condition of described emulation, the thickness of wall 150 " d " can be at least 40 μ m, so that generate the N/S ratio less than 2.5%.Preferably, the thickness of wall 150 " d " can be 50 μ m or bigger, so that generate 1.5% or littler N/S ratio.Yet the thickness of wall " d " can be according to the optical design parameter, cuts apart/the noise reflectivity in reflection horizon 140 etc. and changing as reflectivity, the light beam of information faces 165.In addition, as mentioned above, by cut apart at the information faces 165 and the light beam that still make the information of recording/distance between the reflection horizon 140 remain on 40 μ m or bigger in, hologram recording layer 160 formed have enough thickness and replace wall 150, can reduce to be attributable to be polarized light beam to cut apart/the noise light beam L3n component of the transmission reconstruction beam L3t of reflection horizon 140 reflections.In addition, holographic information recording/reproducer comprises punctured element (pin hole element) 285 (with reference to Figure 12) according to an exemplary embodiment of the present invention, and described punctured element is arranged on photoelectric detector 290 the place aheads, thereby restriction defocuses the detection of light.Therefore, can further reduce or eliminate and be attributable to be polarized light beam and cut apart/the noise light beam L3n component of the transmission reconstruction beam L3t of reflection horizon 140 reflections.
In the above in the exemplary embodiment of Miao Shuing, servo layer 120 is placed in substrate 110 and light beam is cut apart/reflection horizon 140 between, but the invention is not restricted to such structure.Fig. 8 to Figure 11 be according to the present invention other exemplary embodiment servo layer 122,124,125 and 145 is arranged on the holographic information storage medium 102,104,106 of diverse location and 108 sectional view.
With reference to Fig. 8, holographic information storage medium 102 can have such structure: wherein, servo layer 122 be placed in light beam cut apart/reflection horizon 140 and wall 150 between.Servo layer 122 is by the light beam that can transmission be used for recoding/reproduction information, and promptly the material of signal beams, reference beam and reconstruction beam forms.Similar to the situation of the holographic information storage medium 100 of Fig. 1, by light beam is cut apart/reflection horizon 140 places between hologram recording layer 160 and the substrate 110, can prevent that thereby the transmission reconstruction beam that passes hologram recording layer 160 is reflected back toward the object lens generted noise, thereby eliminate this noise source.Except servo layer 122, the element in the exemplary embodiment of Fig. 8 is identical with the element of the holographic information storage medium of describing referring to figs. 1 through Fig. 6 100, therefore will omit the detailed description to them.
With reference to Fig. 9, holographic information storage medium 104 has such structure: wherein, servo layer 124 is placed between information recording layer 160 and the overlayer 170.Servo layer 124 is by the light beam that can transmission be used for recoding/reproduction information, and promptly the material of signal beams, reference beam and reconstruction beam forms.Similar to the situation of the holographic information storage medium 100 of Fig. 1, by light beam is cut apart/reflection horizon 140 places between hologram recording layer 160 and the substrate 110, can prevent that thereby the transmission reconstruction beam that passes hologram recording layer 160 is reflected back toward the object lens generted noise, thereby eliminate this noise source.Except servo layer 124, the element in the exemplary embodiment of Fig. 9 is identical with the element of the holographic information storage medium of describing referring to figs. 1 through Fig. 6 100, therefore will omit the detailed description to them.
With reference to Figure 10, holographic information storage medium 106 has such structure: wherein, servo layer 125 is placed in the hologram recording layer 160.Servo layer 125 is by the light beam that can transmission be used for recoding/reproduction information, and promptly the material of signal beams, reference beam and reconstruction beam forms.Similar to the situation of the holographic information storage medium 100 of Fig. 1, by light beam is cut apart/reflection horizon 140 places between hologram recording layer 160 and the substrate 110, can prevent that thereby the transmission reconstruction beam that passes hologram recording layer 160 is reflected back toward the object lens generted noise, thereby eliminate this noise source.Except servo layer 125, the element in the exemplary embodiment of Figure 10 is identical with the element of the holographic information storage medium of describing referring to figs. 1 through Fig. 6 100, therefore will omit the detailed description to them.
Among the embodiment of Miao Shuing, the wavelength of servo beam is different from the wavelength of the light beam that is used for recoding/reproduction information in the above, but the invention is not restricted to such layout.With reference to Figure 11, holographic information storage medium 108 does not have independent servo layer, and use light beam cut apart/reflection horizon 145 is as servo layer.Can use the independent light beam different as servo beam, but the invention is not restricted to such layout with the light beam that is used for recoding/reproduction information.For example, the light beam that is used for recoding/reproduction also can be used as servo beam.When the independent light beam different with the light beam that is used for recoding/reproduction information when the servo beam, light beam cuts apart/reflection horizon 145 is designed to reflect servo beam.When the light beam that is used for recoding/reproduction information also was used as servo beam, the reconstruction beam of reflection was as servo beam.
Figure 12 illustrates the optical configuration according to the holographic information recording/reproducer of the embodiment of the invention.
With reference to Figure 12, according to the holographic information recording/reproducer of current exemplary embodiment is to be used to record the information on the holographic information storage medium 100 of Fig. 1 and from the equipment of holographic information storage medium 100 information reproductions of Fig. 1, and comprise optical pickup apparatus 200 and circuit unit (not shown), wherein, optical pickup apparatus 200 emissions have the signal beams L1 and the reference beam L2 of orthogonal polarization direction separately, and circuit unit is used to control the driving and the Signal Processing of optical pickup apparatus 200.
Optical pickup apparatus 200 comprises light source 210, first beam splitter 220, half-wave plate 230, optical gate (shutter) 240, second beam splitter 250, the 3rd beam splitter 260, catoptron 225, quarter-wave plate 285, object lens 280 and photoelectric detector 290.Optical pickup apparatus 200 also can comprise focal point control unit 270 and 275, is used for changing respectively the focal position of signal beams L1 and reference beam L2, so as in a plurality of layer recoding/reproduction information.In addition, optical pickup apparatus 200 also can comprise punctured element 295, is used to stop the noise light beam that defocuses to be incident on photoelectric detector 290.In addition, optical pickup apparatus 200 also can comprise and is used to carry out servo-controlled servo optical system (not shown).
Light source 210 can only be launched the light with P polarization, and can comprise the semiconductor laser diode of for example launching blue light.For convenience, the polarisation of light direction of launching is described as the P polarization, but the invention is not restricted to the P polarization.Alternatively, light source 210 can be launched nonpolarized light, can utilize independent polarization plates (not shown) to select to have the light of preset lines polarization from described nonpolarized light.Light source 210 also can be used as servo light source, perhaps can adopt independent servo light source.When adopting independent servo light source, the wavelength of servo beam can be different from from light source 210 wavelength of light emitted.First beam splitter 220, second beam splitter 250 and the 3rd beam splitter 260 are examples of light path cutting unit.In first beam splitter 220 and second beam splitter 250 each is as half anti-mirror (half mirror), and the light that described half anti-mirror will pass first beam splitter 220 and second beam splitter 250 is divided into the light of propagating on two light paths.The light with P polarization of emission is divided into signal beams L1 and the reference beam L2 that all has the P polarization by first beam splitter 220 from light source 210.The signal beams L1 of being cut apart by first beam splitter 220 with P polarization is converted to the light with S polarization by half-wave plate 230, and passes second beam splitter 250 and the 3rd beam splitter 260.Optical gate 240 stops light according to electric signal, and is set on the light path of signal beams L1.When just in recorded information, according to the electric signal of indication with recorded information, optical gate 240 passes through signal beams L1; When just at information reproduction, according to indication reconstruction by reflection light beam L3r with the electric signal that is blocked, optical gate 240 blocking reflected reconstruction beam L3r.The light path of the reference beam L2 of being cut apart by first beam splitter 220 with the P polarization mirror 225 that is reflected changes, thereby reference beam L2 propagates towards the 3rd beam splitter 260.The 3rd beam splitter 260 is that reflection has the signal beams L1 of S polarization and the polarization beam apparatus of the reference beam L2 that transmission has the P polarization.Therefore, signal beams L1 is incident on the 3rd beam splitter 260 along different light paths with reference beam L2.Then, described light path is combined in the 3rd beam splitter 260, thereby the signal beams L1 with S polarization propagates towards quarter-wave plate 285 with the reference beam L2 with P polarization.
The S polarization that is incident on the signal beams L1 on the quarter-wave plate 285 is converted into Left-hand circular polarization L.The P polarization that is incident on the reference beam L2 on the quarter-wave plate 285 is converted into right-hand circular polarization R.Signal beams L1 and reference beam L2 with orthogonal polarization direction of conversion are incident on the holographic information storage medium 100 through object lens 280, thereby as with reference to the described recording holographic information of Fig. 3 to Fig. 5.
Focal point control unit 270 and 275 can comprise beam expander (beam expander), as relay lens group 271,272,276 and 277.Focal point control unit 270 and 275 is designed to: at least one lens in the relay lens group 271,272,276 and 277 can be under the control of driver element (not shown), moves along the direction of the indicated light path of the four-headed arrow among Figure 12.By at least one lens in relay lens group 271,272,276 and 277 are moved along the direction of light path, focal point control unit 270 and 275 can change signal beams L1 in holographic information storage medium 100 and the focus of reference beam L2.Focal point control unit 270 and 275 can be recorded in a plurality of layers of holographic information storage medium 100 information.That is, when signal beams L1 and reference beam L2 are focused on focal point F (referring to Fig. 3) in the holographic information storage medium 100 and go up, form information faces 165.Along with the focal position of signal beams L1 and reference beam L2 changes by focal point control unit 270 and 275, on the depth direction of holographic information storage medium 100, form a plurality of information faces 165 (not shown).Therefore, can be at executive logging in a plurality of layer.In current exemplary embodiment, focal point control unit 270 and 275 comprises beam expander, and described beam expander comprises for example relay lens group 271,272,276 and 277, but the invention is not restricted to such structure.For example, can utilize liquid crystal lens (liquid crystal lens) to realize focal point control unit 270 and 275.When voltage was applied to liquid crystal lens, the light beam with predetermined polarisation was owing to the orientation of the liquid crystal of liquid crystal lens is refracted.The structure of liquid crystal lens is known for those of ordinary skills, therefore with the descriptions thereof are omitted.Such liquid crystal lens can replace relay lens group 271,272,276 and 277 to be set on signal beams L1 and the reference beam L2 light path separately, and voltage can be applied to liquid crystal lens.Therefore, the focus of signal beams L1 and reference beam L2 can change.
When information was reproduced, the incident reconstruction beam L3i that launches from light source 210 passed first beam splitter 220, catoptron 225, the 3rd beam splitter 260, quarter-wave plate 285 and object lens 280, and is incident on the holographic information storage medium 100.Incident reconstruction beam L3i is recorded information faces 165 (referring to Fig. 6) reflection of information with the interference pattern form in the holographic information storage medium 100, and incident is returned on the object lens 280.Because incident reconstruction beam L3i propagates along the light path identical with reference beam L2, so incident reconstruction beam L3i is incident on the holographic information storage medium 100 with the right-hand circular polarization state.The reconstruction by reflection light beam L3r that is reflected by information faces 165 is converted into the Left-hand circular polarization light beam, and object lens 280 are returned in incident.Reconstruction by reflection light beam L3r with Left-hand circular polarization passes quarter-wave plate 285 and is converted into the S light beam, by 260 reflections of the 3rd beam splitter, and passes second beam splitter 250 to be detected by photoelectric detector 290.The part of reconstruction by reflection light beam L3r can still be stopped by optical gate that by this partial reflection reconstruction beam L3r of second beam splitter, 250 reflections wherein, described optical gate is closed by 250 reflections of second beam splitter when information reproduction.When in a plurality of layer at hologram recording layer 160 (referring to Fig. 6) during recorded information, the focal point control unit 275 that is used to change the focal position of reference beam L2 by utilization changes the focal position of incident reconstruction beam L3i, and the focal position of incident reconstruction beam L3i can be set at and will read from it on information faces 265 of information.
Punctured element 295 stops the light of any element reflects except the information faces 165 that reads information from it.Punctured element 295 comprises preset aperture (that is, pin hole 295a) as shown in figure 13 and the restraining barrier 295b that stops light, and is set at photoelectric detector 290 the place aheads.The radius R h of pin hole 295a can be greater than the radius R s of light beam spot S.For example, radius R h can be the twice of the radius of light beam spot S.Punctured element 295 stops defocused beam.With reference to Figure 14, when being set at, the focal position of incident reconstruction beam will read from it on information faces 165 of information, and when the pin hole 295a of punctured element 295 is set at the place, focal position that is focused by the reconstruction by reflection light beam of information faces 165 reflections of holographic information storage medium 100 in optical pickup apparatus 200 (referring to Figure 12), the light of any element reflects except information faces 165, for example when transmission reconstruction beam L3t be polarized light beam and cut apart/reflection horizon 140 partly the noise light beam L3n (referring to Fig. 6) that defocuses that generates of reflex time almost be blocked a layer 295b and stop fully.Therefore, can be by except aforesaid wall 150, punctured element 295 being set, reduce or eliminate to be attributable to be polarized light beam and to cut apart/noise of the noise light beam L3n of reflection horizon 140 reflections.
Fig. 6 is described as reference, when information reproduction, the transmission reconstruction beam L3t that passes hologram recording layer 160 from incident reconstruction beam L3i is polarized light beam to be cut apart/reflection horizon 140 transmissions, be polarized light beam by the transmission reconstruction beam L3t ' of the reflection of reflections such as servo layer 120 to cut apart/reflection horizon 140 stops.In addition, even the part of transmission reconstruction beam L3t is polarized light beam to be cut apart/reflection horizon 140 reflection, the wall 150 that also can be by holographic information storage medium 100 is set and/or the punctured element 295 of holographic information recording/reproducer reduce or eliminate noise.
The method and apparatus that shows particularly and described holographic information storage medium and utilized described holographic information storage medium recording/reproducing holographic information with reference to exemplary embodiment of the present invention.From these exemplary embodiments as can be seen, by the light beam that will optionally reflect and transmission has the circularly polarized light beam of orthogonal polarization orientation separately cut apart/reflection horizon places between hologram recording layer and the substrate to reduce or to eliminate the noise that is caused by reflected light, prevented that transmission is reflected back toward object lens by the transmission reconstruction beam of hologram recording layer as the noise light beam, thereby reduced or eliminated the noise that causes by reflected light.
Although shown and described exemplary embodiment of the present invention, but those skilled in the art should understand that, and, under the situation that does not break away from true scope of the present invention, can carry out various changes and modification and can be equal to replacement its element along with the development of technology.Without departing from the scope of the invention, can carry out many modifications, displacement, interpolation and sub-portfolio, so that instruction of the present invention is adapted to concrete condition.Therefore, the present invention is not intended to and is limited to disclosed each exemplary embodiment, but the present invention includes all embodiment in the scope that falls into claim and equivalent thereof.

Claims (24)

1. holographic information storage medium comprises:
Substrate;
Overlayer receives first circularly polarized light beam with first polarization direction and second circularly polarized light beam with second polarization direction, wherein, and second polarization direction and the first polarization direction quadrature;
Light beam is cut apart/reflection horizon, is arranged between substrate and the overlayer, be used in first polarization direction that keeps first light beam, reflecting first light beam, and transmission second light beam;
Hologram recording layer, be arranged on light beam to cut apart/reflection horizon and overlayer between, be used for cutting apart/first light beam of reflective layer reflects and second light beam that receives by overlayer be recorded as information the interference pattern that is formed on hologram layer by being polarized light beam.
2. medium according to claim 1, wherein, described light beam cuts apart/and the reflection horizon comprises cholesteric crystal material.
3. medium according to claim 1, wherein, described light beam cuts apart/and the reflection horizon comprises the liquid crystal film that is in liquid crystal state or sclerosis attitude.
4. medium according to claim 1, wherein, light beam cuts apart/and the reflection horizon comprises single cholesteric liquid crystal layer or a plurality of cholesteric liquid crystal layer, wherein, the liquid crystal molecule of described a plurality of cholesteric liquid crystal layer has different spiralization cycles for each cholesteric liquid crystal layer in described a plurality of cholesteric liquid crystal layer.
5. medium according to claim 1, wherein, hologram recording layer comprises photopolymer or thermoplastic resin.
6. medium according to claim 1, also comprise: servo layer, be arranged on substrate and light beam to cut apart/reflection horizon between, perhaps be arranged on light beam to cut apart/reflection horizon and hologram recording layer between, perhaps be arranged in the hologram recording layer, perhaps be arranged between hologram recording layer and the overlayer.
7. medium according to claim 1, wherein, light beam cuts apart/and the reflection horizon records servo-information.
8. medium according to claim 1 also comprises: wall, be arranged on light beam to cut apart/reflection horizon and hologram recording layer between.
9. medium according to claim 8, wherein, the thickness of wall is equal to or greater than 40 μ m.
10. medium according to claim 1, wherein, light beam cuts apart/and the distance with between any information faces of information in reflection horizon and the hologram recording layer is equal to or greater than 40 μ m.
11. medium according to claim 1, wherein:
Information is recorded in along in a plurality of information faces of the depth direction arrangement of hologram recording layer;
Be polarized light beam to cut apart/first light beam of reflective layer reflects and all have along the depth direction of hologram recording layer by second light beam that overlayer receives arranges and consistent with described a plurality of information faces respectively a plurality of focal positions.
12. medium according to claim 1, wherein, the information that is registered as interference pattern is recorded specially for unit with digital ratio.
13. one kind is used to record the information on the holographic information storage medium and/or from the holographic information recording/reproducer of holographic information storage medium information reproduction, described holographic information storage medium comprises: substrate; Overlayer; Light beam is cut apart/reflection horizon, be arranged between substrate and the overlayer, be used to reflect first polarization direction that first circularly polarized light beam with first polarization direction keeps first light beam simultaneously, and transmission has second circularly polarized light beam with second polarization direction of the first polarization direction quadrature; Hologram recording layer, be arranged on light beam to cut apart/reflection horizon and overlayer between, described equipment comprises:
Optical pickup apparatus, generation has first circularly polarized light beam of first polarization direction and has second circularly polarized light beam with second polarization direction of the first circular polarization quadrature, and launch first light beam and second light beam is incident on the overlayer of holographic information storage medium first light beam and second light beam, make:
First light beam is polarized light beam and cuts apart/reflective layer reflects;
Be polarized light beam to cut apart/first light beam of reflective layer reflects and be incident on the focus place of supratectal second light beam in hologram recording layer and form interference pattern;
Hologram recording layer is recorded as information the interference pattern at focus place.
14. equipment according to claim 13, wherein, in order to reproduce the information that is registered as interference pattern in the hologram recording layer, second light beam that the optical pickup apparatus emission has second polarization direction is incident on the overlayer of holographic information storage medium second light beam, makes:
Second light beam with second polarization direction is partly reflected the reconstruction by reflection light beam that has first polarization direction with formation by the interference pattern in the hologram recording layer, by the interference pattern in the hologram recording layer partly transmission have the transmission reconstruction beam of second polarization direction with formation;
The reconstruction by reflection light beam is incident on the optical pickup apparatus;
The transmission reconstruction beam passes light beam to be cut apart/reflection horizon;
Light beam cuts apart/reflection horizon stop pass light beam at the transmission reconstruction beam and cut apart/reflection horizon after any reflected light of reflection generation by the transmission reconstruction beam be incident on the optical pickup apparatus.
15. equipment according to claim 13, wherein, optical pickup apparatus comprises that focus changes the unit, is used for changing along the depth direction of hologram recording layer the position of focus.
16. equipment according to claim 16, wherein, focus changes the unit and comprises beam expander or liquid crystal lens.
17. equipment according to claim 13, wherein, optical pickup apparatus comprises punctured element, is used to stop the light from any point reflection except focus.
18. equipment according to claim 13, wherein, the information that is recorded as interference pattern at the focus place is recorded specially for unit with digital ratio.
19. one kind is used to record the information on the holographic information storage medium and/or from the holographic information recording/reproducer of holographic information storage medium information reproduction, described holographic information storage medium comprises: substrate; Overlayer; Light beam is cut apart/reflection horizon, be arranged between substrate and the overlayer, be used to reflect first polarization direction that first circularly polarized light beam with first polarization direction keeps first light beam simultaneously, and transmission has second circularly polarized light beam with second polarization direction of the first polarization direction quadrature; Hologram recording layer, be arranged on light beam to cut apart/reflection horizon and overlayer between, be used for cutting apart by being polarized light beam/first light beam of reflective layer reflects and second light beam be recorded as the interference pattern at the focus place that is formed on hologram recording layer with information, and described equipment comprises:
Optical pickup apparatus generates second circularly polarized light beam have with second polarization direction of the first polarization direction quadrature, and launches second light beam second light beam is incident on the overlayer of holographic information storage medium, makes:
Second light beam with second polarization direction is partly reflected the folded light beam that has first polarization direction with formation at the focus place by the interference pattern in the hologram recording layer, by the interference pattern in the hologram recording layer partly transmission have the transmitted light beam of second polarization direction with formation;
Folded light beam is incident on the optical pickup apparatus;
Transmitted light beam passes light beam to be cut apart/reflection horizon;
Light beam cuts apart/reflection horizon stop pass light beam at transmitted light beam and cut apart/reflection horizon after any reflected light of reflection generation by transmitted light beam be incident on the optical pickup apparatus.
20. one kind records the information on the holographic information storage medium and/or from the method for holographic information storage medium information reproduction, described holographic information storage medium comprises: substrate; Overlayer; Light beam is cut apart/reflection horizon, be arranged between substrate and the overlayer, be used to reflect first polarization direction that first circularly polarized light beam with first polarization direction keeps first light beam simultaneously, and transmission has second circularly polarized light beam with second polarization direction of the first polarization direction quadrature; Hologram recording layer, be arranged on light beam to cut apart/reflection horizon and overlayer between, described method comprises:
Generation has first circularly polarized light beam of first polarization direction and has second circularly polarized light beam with second polarization direction of the first polarization direction quadrature;
To the overlayer of holographic information storage medium, make win light beam and second light beam pass overlayer first light beam and second beam emissions;
Make to be polarized light beam and to cut apart/first light beam with first polarization direction of reflective layer reflects focuses on the focus place in the holographic recording medium;
Make second light beam that passes overlayer and have second polarization direction focus on described focus place in the hologram recording layer, make win light beam and second beam interference near described focus, forming interference pattern, thereby information is registered as the interference pattern in the hologram recording layer.
21. method according to claim 20 wherein, generates first circularly polarized light beam with first polarization direction and the step that has with second circularly polarized light beam of second polarization direction of the first polarization direction quadrature comprises:
The linearly polarized light that only has first linear polarization from light emitted;
Generate first linearly polarized light beam with first polarization direction from linearly polarized light;
Generate second linearly polarized light beam have with second polarization direction of the first polarization direction quadrature from linearly polarized light;
Generate first circularly polarized light beam and generate second circularly polarized light beam from first linearly polarized light beam, perhaps generate first circularly polarized light beam and generate second circularly polarized light beam from first linearly polarized light beam from second linearly polarized light beam from second linearly polarized light beam.
22. method according to claim 20 also comprises: reproduce the information that is registered as interference pattern in the hologram recording layer;
Wherein, reproducing the step that is registered as the information of interference pattern in the hologram recording layer comprises:
Second light beam that emission has second polarization direction is incident on the overlayer of holographic information storage medium second light beam, so that second light beam passes overlayer, and is reflected at least in part to form the reconstruction by reflection light beam by the interference pattern in the hologram recording layer;
From reconstruction by reflection beam detection hologram recording layer, be registered as the information of interference pattern.
23. method according to claim 20, wherein, the information that is recorded as interference pattern is recorded specially for unit with digital ratio.
24. method according to claim 20 also comprises: change the position of focus along the depth direction of hologram recording layer, with recorded information on a plurality of information faces of arranging along the depth direction of hologram recording layer.
CN200880103156A 2007-08-13 2008-05-22 Holographic information storage medium, and method and apparatus for recording/reproducing holographic information using the same Pending CN101779240A (en)

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KR10-2007-0129901 2007-12-13
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107767887A (en) * 2017-12-06 2018-03-06 苏州盤谷信息光学有限公司 A kind of holographic memory device based on dichroic reflective layer
CN112823315A (en) * 2018-10-16 2021-05-18 凸版印刷株式会社 Integrated 3-dimensional display and identification information recording method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107767887A (en) * 2017-12-06 2018-03-06 苏州盤谷信息光学有限公司 A kind of holographic memory device based on dichroic reflective layer
CN112823315A (en) * 2018-10-16 2021-05-18 凸版印刷株式会社 Integrated 3-dimensional display and identification information recording method

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