CN111508534B - Polarization balance measurement reading method and device based on nano photoetching optical disk - Google Patents

Polarization balance measurement reading method and device based on nano photoetching optical disk Download PDF

Info

Publication number
CN111508534B
CN111508534B CN201910093645.7A CN201910093645A CN111508534B CN 111508534 B CN111508534 B CN 111508534B CN 201910093645 A CN201910093645 A CN 201910093645A CN 111508534 B CN111508534 B CN 111508534B
Authority
CN
China
Prior art keywords
writing
polarization
laser
birefringent
information
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910093645.7A
Other languages
Chinese (zh)
Other versions
CN111508534A (en
Inventor
王中阳
张力
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Advanced Research Institute of CAS
Original Assignee
Shanghai Advanced Research Institute of CAS
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 Shanghai Advanced Research Institute of CAS filed Critical Shanghai Advanced Research Institute of CAS
Priority to CN201910093645.7A priority Critical patent/CN111508534B/en
Publication of CN111508534A publication Critical patent/CN111508534A/en
Application granted granted Critical
Publication of CN111508534B publication Critical patent/CN111508534B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/005—Reproducing
    • G11B7/0052—Reproducing involving reflectivity, absorption or colour changes
    • 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
    • G11B7/0045—Recording
    • 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
    • G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
    • 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
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1372—Lenses
    • G11B7/1376—Collimator lenses
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/2403—Layers; Shape, structure or physical properties thereof
    • G11B7/24035—Recording layers
    • 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
    • G11B7/24053—Protective topcoat layers lying opposite to the light entrance side, e.g. layers for preventing electrostatic charging
    • 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
    • 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
    • G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
    • G11B2007/00709—Dimensions of grooves or tracks, e.g. groove depth, track pitch

Abstract

The invention provides a polarization balance measurement reading method and device based on a nano photoetching optical disk. The method adopts the nano photoetching method to write the information stored in the ultra-high density optical disk, adopts the birefringence writing recording material to store the information, adopts the photoinduced birefringence recording material to store the erasable information, and can realize the erasable repeated information recording of the nano photoetching optical disk. The reading method comprises the following steps: reading the optical disc information by a polarization balance measurement reading method; the quick reading of the multidimensional storage information of the optical disk can be realized by adopting a digital information coding and decoding method. The invention is beneficial to reducing the size and the distance of the information recording points, improving the storage density of the optical disk, realizing the stable and long-term storage of the optical disk storage information and effectively extracting the ultrahigh-density optical disk storage information at high speed.

Description

Polarization balance measurement reading method and device based on nano photoetching optical disk
Technical Field
The present application relates to the field of optical technologies, and in particular, to a method and an apparatus for measuring and reading polarization balance based on a nano-lithography optical disc, and a method and an apparatus for writing and reading erasable nano-lithography.
Background
With the development of technologies such as gene sequencing and brain activity reading, not only a large amount of data is generated, but also higher requirements are put forward on how to effectively, stably and accurately store the data. Based on the above background, the optical disc storage technology has advantages of energy saving, long storage life, good safety, easy processing, etc., and thus, the optical disc storage technology well complies with the requirements of the times. For optical disc technology, the limitation of storage capacity has seriously hindered the development of optical disc technology.
In order to increase the capacity of an optical disc, the conventional technical route is to reduce the size of a recording spot. With the successful development of short wavelength laser diodes (GaN blue-green lasers), blu-ray discs are becoming the mainstream storage mode in the optical disc market. In the early CD, the recording laser wavelength was 780nm, the numerical aperture was 0.45, the track pitch was 1.6 μm, and the single-layer storage capacity was only 650 MB; later DVD optical disk, recording laser wavelength is 650nm, numerical aperture is 0.6, track pitch is 0.74 μm, single-layer storage capacity is 4.7 GB; the current blue-ray disc has the recording laser wavelength of 405nm, the numerical aperture of 0.85 and the track spacing of 0.32 mu m, the track spacing is only half of that of a red-ray DVD disc (0.74 mu m), the single-layer storage capacity is up to 25GB, and meanwhile, the blue-ray disc achieves the multi-layer writing effect by utilizing different reflectivities, thereby realizing 12-layer 300GB blue-ray disc storage.
In order to further break through the limitation of the storage capacity of the optical disc, some methods for increasing the storage capacity have been proposed by researchers. The 2009 australian sensitivity research team utilized the differences in the response of gold nanowires of different aspect ratios to laser light of different wavelengths and polarization directions to achieve three-layer five-dimensional (and polarization) optical information storage within thickness (Nature,2009,459(7245): 410-. In 2011, a S.W Hell research team provides a novel microscopic technology RESOLFT (reversible structural optical 'fluorescence' transition between two states) for super-resolution optical storage reading and writing, and a high-density optical storage experiment (Nature,2011,478,204 and 208) with a point spacing of 250nm is realized by using the photocuring and photoswitch characteristics of green fluorescent protein (rseFP) and a super-resolution writing and reading method. The suspicion research team in australia in 2012 combines the photopolymerization and the super-resolution stimulated emission loss technical principle, utilizes a 1, 5-bis (p-dimethylaminociocinnimide) cyclopentanone (BDCC) material system to realize the photoetching channel width of 9nm and the channel spacing of 52nm (Nature Communications,2013,4.6:2061), and the mechanism of photopolymerization photoetching can be used for writing optical disc information at high density. Accordingly, the allergy research team filed for international patents (Appl. No:15/039,368; PCT No: PCT/AU 2013/001378).
Disclosure of Invention
The present application aims to provide a method and an apparatus for measuring and reading polarization balance based on a nano-lithography optical disc, so as to improve the storage density and capacity of the optical disc and improve the read-write speed of the optical disc.
To achieve the above and other related objects, the present application provides a polarization balance measurement reading method, including: irradiating a fixed recording position of one or more grooves with depth information on a birefringent writing recording layer made of a birefringent material by linear polarization laser with a fixed polarization direction; linear superposed laser with different polarization directions reflected by the birefringence writing recording layer is obtained; splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser; and measuring the intensities of the S component and the P component so as to read out corresponding stored information.
In one embodiment of the present application, the characterization 2 is performed by one or more grooves with depth information at the fixed recording position m Carrying out storage information in a system counting mode; wherein m represents the number of the grooves, and the depth information is used for representing 2 through whether the grooves have the depth information or not m The value of the stored information in the binary count mode is 1 or 0.
In an embodiment of the present application, the data dimension X of the storage information is represented by a plurality of depth information on each of the trenches, so as to realize X m Carrying out storage information in a system counting mode; characterizing X by different depth values in the depth information on the trench m And carrying out data dimension X of the storage information in a binary counting mode.
In an embodiment of the present application, the number m of the grooves is associated with a resolution of a polarization balance measurement method, and the stronger the resolution, the greater the number of the grooves is determined.
In an embodiment of the present application, the method for measuring the intensities of the S component and the P component for reading out the corresponding stored information includes: the intensities of the S-component and P-component corresponding to one or more of the trenches at the fixed recording location are expressed as:
Figure BDA0001963959030000021
Figure BDA0001963959030000022
wherein i represents the line bias laserThe included angle between the polarization direction reflected by the un-engraved birefringent layer and the S component; α, β, γ.. indicate the included angles between the S components and the different polarization directions of the line bias laser reflected by the birefringent layer after the action of the birefringent layer; m represents the number of the trenches having the depth information; a 1 or 0 in the matrix represents whether the depth information is on the trench.
In an embodiment of the present application, the method for measuring the intensities of the S component and the P component for reading out the corresponding stored information includes: the intensities of the S-component and P-component corresponding to one or more grooves with different depth information at the fixed recording location are represented as:
Figure BDA0001963959030000031
Figure BDA0001963959030000032
wherein i represents an included angle between the polarization direction of the linear bias laser reflected after the action of the un-written birefringent layer and the S component; α, β, γ.. indicate the included angles between the S components and the different polarization directions of the line bias laser reflected by the birefringent layer after the action of the birefringent layer; m represents the number of the trenches having the depth information; 0-x in the matrix are represented as different writing depth values in said depth information on said groove.
In an embodiment of the present invention, the wavelength of the linearly polarized laser with a fixed polarization direction is selected to have a low absorption rate for the absorption modulation layer, so as to avoid the same wavelength as the write laser wavelength.
In one embodiment of the present application, the birefringent material includes: 1) the film polarization material formed by the dielectric film stack is formed by coating a film by a physical vapor deposition method, and the adopted material comprises one or more of MgF2, SiO2, ZrO2, TiO2 and HfO 2; 2) organic polymer materials, which comprise any one or more of azo polymer, azo liquid crystal material, PMMA, PE, PI and polyester material; 3) a birefringent sculpturing film comprising any one or combination of more of SiO2, TiO2, and ZnS; 4) a birefringent crystal material comprising any one or a combination of calcite, lithium niobate, lithium tantalate, and barium niobate; 5) the optical rotation material changes the polarization plane when light passes through the material, and comprises one or more of quartz and optical rotation high molecular polymer.
In an embodiment of the present application, the storage information stored in the birefringent writing recording layer is written by a single-beam nanolithography writing method or a dual-beam nanolithography writing method.
In an embodiment of the present application, the single-beam nanolithography writing method includes: the method comprises the steps of compressing the size of a diffraction-limited focusing light spot by adopting a focusing mode of a short-wavelength writing laser beam and a high-numerical-aperture objective lens so as to realize the writing of nano-scale photoetching information; the short wavelength writing laser beam acts on the birefringence writing recording layer, and the etching depth and width of the recording layer are accurately controlled by controlling the irradiation time and laser intensity of the short wavelength writing laser beam.
In an embodiment of the present application, the dual-beam nanolithography writing method includes: solid writing light beams and hollow suppression light beams with different wavelengths are adopted to simultaneously irradiate an absorption modulation layer which is formed by absorption modulation materials in a physical storage medium of the optical disk so as to realize super-resolution nano photoetching writing through an absorption modulation effect; focal planes of the solid writing light beams and the hollow suppression light beams are overlapped in space, and the light intensity of the solid writing light beams accords with Gaussian intensity distribution to write information; the light intensity of the hollow suppression light beam conforms to the annular intensity distribution so as to suppress peripheral light spots of the solid writing light beam from transmitting through the absorption modulation layer; and respectively controlling the irradiation time and the beam intensity of the solid writing beam and the hollow suppression beam to realize the accurate control of the etching depth and the etching width of the information recording layer.
To achieve the above and other related objects, the present application provides an erasable nano writing and reading method, the method comprising: compressing the focal spot size of the solid writing beam; the solid writing light beam acts on the writing birefringence writing recording layer, so that the writing birefringence writing recording layer material generates a photoinduced birefringence effect, and the reversible refractive index change of the writing light beam acting area material is generated; controlling the size of a recording spot at a fixed recording position on the birefringent writing recording layer by controlling the beam intensity and the action time of the solid writing beam; one or more fixed recording positions with different recording dot sizes are recorded on the birefringent writing recording layer made of a light-induced birefringent material by irradiating the birefringent writing recording layer with a linearly polarized laser with a fixed polarization direction; linear superposed laser with different polarization directions reflected by the birefringence writing recording layer is obtained; splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser; and measuring the intensities of the S component and the P component so as to read out the corresponding stored information.
In an embodiment of the present application, the stored information on the birefringent writing recording layer is erased by changing the refractive index of the birefringent writing recording layer by light irradiation or heating.
In an embodiment of the present application, the birefringent writing recording layer material has a photo-induced birefringence property, including: 1) organic polymer material, which comprises any one or more combination of azo polymer, azo liquid crystal material, PMMA, PE, PI and polyester material; 2) the metal ion doped lithium niobate crystal material comprises one or more of ferromanganese double doping, Mg and Fe.
In an embodiment of the application, the method for changing the refractive index of the birefringent writing recording layer by light irradiation or heating further includes: the illumination intensity or the illumination time is adjusted to realize accurate control; or, the precise control can be realized by adjusting the heating temperature or the heating time.
To achieve the above and other related objects, the present application provides a polarization balance measurement reading apparatus, comprising: the polarization module is used for irradiating a fixed recording position etched with one or more grooves with depth information on a birefringent writing recording layer made of a birefringent material by linear polarization laser with a fixed polarization direction; the measuring module is used for obtaining linear superposed laser of different polarization directions reflected by the birefringence writing recording layer through the linear polarized laser; splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser; and measuring the intensities of the S component and the P component so as to read out corresponding stored information.
In an embodiment of the present application, the optical path module includes: the device comprises a linear polarization laser, a first coupling lens, a polarization maintaining optical fiber, a first collimating lens, an 1/2 lambda plate, a polarization compensator, a dichroic mirror and a high-power objective lens; the linear polarization laser is used for emitting linear polarization laser with stable power and linear polarization direction; the first coupling lens, the polarization-maintaining optical fiber, the first collimating lens, the 1/2 lambda plate, the polarization compensator and the dichroic mirror are sequentially arranged from bottom to top; wherein the first coupling lens is used for focusing the linearly polarized laser; the polarization maintaining optical fiber is used for ensuring the polarization direction of the linear polarization laser and filtering and shaping the light beam; the collimating lens is used for ensuring the collimation of the line bias laser; the 1/2 lambda plate is used for adjusting the polarization direction of the linearly polarized laser; the polarization compensator is used for compensating the polarization change of the linearly polarized laser; the dichroic mirror is arranged at a certain angle with the emergent direction of the line-polarized laser and is used for changing the emission path of the line-polarized laser; the high power objective lens is arranged on a path of the birefringent writing recording layer after the emission path of the birefringent writing recording layer is changed, and is used for focusing the line bias laser on a fixed recording position of the birefringent writing recording layer, wherein grooves with different thicknesses are etched on the fixed recording position.
In an embodiment of the present application, the measurement module includes: the high-power objective lens, the beam splitter, the polarization beam splitter, the first focusing lens, the second focusing lens, the first detector and the second detector; the high power objective lens and the beam splitter are sequentially arranged on a path of the line bias laser reflected by the birefringent writing recording layer; the high-power objective lens is used for collecting the linear bias laser to obtain linear superposed laser in different polarization directions; the beam splitter is used for splitting the collected linear polarization laser and changing the collected linear polarization laser to the polarization beam splitter; the polarization beam splitter is arranged on a path of which the collection path is changed by the beam splitter, and the first focusing lens and the first detector are respectively and sequentially arranged on a first path of the polarization beam splitter; the second focusing lens and the second detector are sequentially arranged on a second path of the polarization beam splitter respectively; the polarization beam splitter is used for splitting the linear superposition laser into an S component and a P component; the first focusing lens and the second focusing lens are used for focusing the S component or the P component; the first detector and the second detector are used for measuring the intensity of the S component or the P component so as to read out corresponding stored information.
To achieve the above and other related objects, the present application provides an erasable nano writing and reading apparatus, the apparatus comprising: a writing module for compressing the focal spot size of the solid writing beam; the solid writing light beam acts on the writing birefringence writing recording layer, so that the writing birefringence writing recording layer material generates a photoinduced birefringence effect, and the reversible refractive index change of the writing light beam acting area material is generated; controlling the size of a recording spot at a fixed recording position on the birefringent writing recording layer by controlling the beam intensity and the action time of the solid writing beam; a reading module for recording one or more fixed recording positions with different recording dot sizes on the birefringent writing recording layer made of the photoinduced birefringent material by linear polarization laser with a fixed polarization direction; linear superposed laser with different polarization directions reflected by the birefringence writing recording layer is obtained; splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser; and measuring the intensities of the S component and the P component so as to read out the corresponding stored information.
As described above, the polarization balance measurement reading method and apparatus based on the nano-lithography optical disc of the present application have the following beneficial effects:
1. method for writing nano photoetching information in and 2 m The bit multi-order information coding method is combined, the information storage density is improved by reducing the size of a recording light spot through a nano photoetching information writing method, and different bits are characterized by using different groove depths2 of the information m The information storage dimensionality is improved by the bit multi-level information coding method, so that the storage density and the storage capacity of the optical disk information storage are greatly improved.
2. Compared with the existing blue-ray disc which stores data by using the refractive index change of materials, the data storage method has higher stability and is more suitable for long-term storage of information.
3. The material absorption modulation characteristic is utilized to compress the focused light spot of the etching beam, and the etching depth and the etching width are accurately controlled by controlling the intensity and the acting time of the etching beam and the inhibiting beam, so that the nano-sized photoetching information writing process is realized.
4. The optical disk information storage recording layer is made of the birefringent material, and compared with other optical disks, the stability of the optical disk information storage recording layer is higher, and the long-term storage of stored information is facilitated.
5. The optical refraction material is used for writing photoetching information, and optical storage recording information can be erased by methods of uniform illumination or heating and the like, so that the erasable repeated writing and recording of the optical disk are realized.
6. The information reading is carried out on the writing information by utilizing a polarization balance measurement reading method, so that the method has higher sensitivity, response speed and resolution capability, and can realize multi-order storage of more dimension information.
Drawings
Fig. 1 is a schematic diagram illustrating a structure and a writing principle of an optical disc physical storage medium according to an embodiment of the present application.
FIG. 2 shows an embodiment of the present application as 2 m Schematic diagram of the principle of multi-level writing.
Fig. 3 is a flowchart illustrating a polarization balance measurement reading method according to an embodiment of the present application.
Fig. 4 is a schematic diagram illustrating a polarization balance measurement reading method according to an embodiment of the present application.
FIG. 5 shows an embodiment of the present application as 2 m The method for coding and writing the bit multi-order information combines the principle schematic diagram of the polarization balance measuring method.
Fig. 6 is a flowchart illustrating an erasable nano writing and reading method according to an embodiment of the present application.
FIG. 7 shows an embodiment of the present application as 2 of the rewritable optical disk m The principle of the bit multi-level information coding method is shown schematically.
Fig. 8A is a schematic structural diagram of a single-beam writing polarization balance measurement reading apparatus according to an embodiment of the present application.
Fig. 8B is a schematic structural diagram of a dual-beam writing polarization balance measurement reading apparatus according to an embodiment of the present application.
Fig. 9 is a block diagram of an erasable nano write and read apparatus according to an embodiment of the present application.
Detailed Description
The following description of the embodiments of the present application is provided by way of specific examples, and other advantages and effects of the present application will be readily apparent to those skilled in the art from the disclosure herein. The present application is capable of other and different embodiments and its several details are capable of modifications and/or changes in various respects, all without departing from the spirit of the present application. It should be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present application, and the drawings only show the components related to the present application and are not drawn according to the number, shape and size of the components in actual implementation, and the type, number and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
In order to improve the storage density and capacity of the optical disc and improve the read-write speed of the optical disc, the application provides a polarization balance measurement reading method and device, and an erasable nano writing and reading method and device, so as to realize the read-write of the information recording points with nano size, have higher storage density and storage capacity and higher read-write speed, and realize the erasable data storage of the optical disc and repeat the information recording for many times.
The polarization balance measurement reading method and apparatus provided in the present application correspond to the "writing method based on nanolithography" in the patent document having application number 201811383960.5 and entitled "optical disc reading and writing method based on nanolithography and writing control information encoding and decoding method". That is, the stored information is inscribed by the "nanolithography based writing method" and then read by the polarization balance measurement reading method described herein.
First embodiment
As shown in fig. 1, a left diagram in fig. 1 shows a physical storage medium of an optical disc, to which both the nanolithography-based writing method and the polarization balance measurement reading method described in this application are applied, and the structure of the optical disc includes:
1) A protective layer 101 that allows the disc to withstand frequent use, fingerprints, scratches and dirt, thereby ensuring the storage quality and data security of the disc;
2) an absorption modulation layer 102, the layer of material having absorption modulation characteristics, the layer thickness being less than 500nm, the absorption modulation layer material including, but not limited to, diarylethenes, fulgides, azides;
3) the birefringent writing recording layer 103 is used for writing and recording information, is characterized by having a birefringent effect, can be stably stored, can be optically written, and is made of calcite, lithium niobate, lithium tantalate, barium niobate and the like, but is not limited to the calcite, the lithium niobate, the lithium tantalate, the barium niobate and the like;
4) the reflective layer 104, which is used to improve the reflectivity of laser light and facilitate the reflection measurement of polarization balance information, is characterized by a material with high reflectivity, mainly including a metal material, etc., but not limited thereto.
In another embodiment, further, a transition protection layer of less than 10nm may be added between the absorption modulation layer 102 and the birefringent writing recording layer 103 as required to protect the recording layer from the absorption modulation layer.
With the physical storage structure of the optical disc, the main process of the writing method based on the nanolithography is as follows:
In conjunction with the physical storage structure of the optical disc, the solid writing beam 105 and the hollow inhibiting beam 106 act on the absorption modulation layer 102 simultaneously, and the hollow inhibiting beam 106 inhibits the peripheral beam of the solid writing beam 105 from transmitting through the absorption modulation layer 102 by the action of the absorption modulation characteristic, so that the size of the writing spot transmitted through the absorption modulation layer is further compressed, as shown in 107, and the beam 110 compressed by the absorption modulation layer 102 acts on the birefringent writing recording layer 103 for information writing.
Second embodiment
A. Both the nanolithography-based writing method and the polarization balance measurement reading method described in this application are combined with 2 m A bit multi-level information coding method. As shown in the right diagram of fig. 1, assuming that m is 3, different groove depths Z are performed at (1), (2), and (3) at fixed recording positions 112 on the birefringent writing recording layer 103 1 ，Z 2 ，Z 3 Wherein the writing at the corresponding position (m) indicates that the recording point is "1", otherwise, the recording point is "0", and the different position (m) corresponds to 2 m Different number of bits in the bit encoding; at this point, the information recording at the fixed recording position 112 is completed, and then the information is moved to the next fixed position according to the example direction of 111, and the above process is repeated to complete the data recording; and the rest is done in sequence to complete the whole process of data storage.
Wherein, for X m The bit multi-level information encoding method is shown in fig. 2. As shown, the optical disc physical storage medium structure includes: an absorption modulation layer 201, a birefringent writing recording layer 202, and a reflective layer 203. Taking X-4 and m-3 as an example, the lithography information is recorded at the corresponding fixed recording positions 204, 205, and 206, respectively. (1) Depth information of the recording groove is Z 1,0 ，Z 1,1 ，Z 1,2 ，Z 1,3 Wherein Z is 1,0 Since data is not stored, writing is not performed, and a groove is not formed in the drawing. Whereby Z 1,0 ，Z 1,1 ，Z 1,2 ，Z 1,3 Respectively corresponding to the recorded data '0, 1,2, 3' at the position (1)"; (2) where the recording groove depth is Z 2,0 ，Z 2,1 ，Z 2,2 ，Z 2,3 Recording data "0, 1,2, 3" at the corresponding position (2), respectively; (3) has a recording groove depth of Z 3,0 ，Z 3,1 ，Z 3,2 ，Z 3,3 Data "0, 1,2, 3" are recorded at the corresponding positions (3), respectively. Thereby realizing 4 at a single recording point 3 And storing the order data.
With the physical storage structure of the optical disc, the main process of the polarization balance measurement reading method is as follows:
fig. 3 shows a polarization balance measurement reading method according to an embodiment of the present application. As shown, the method comprises:
step S301: a fixed recording position of one or more grooves having depth information is etched on a birefringent writing recording layer made of a birefringent material by irradiating the birefringent writing recording layer with a linearly polarized laser of a fixed polarization direction.
In this embodiment, this step takes over the nanolithography-based writing method described above. By the writing method based on nanolithography, a fixed recording position containing one or more grooves with depth information is etched on the birefringent writing recording layer of the optical disc physical storage medium as shown in fig. 1.
In an embodiment of the present application, the storage information stored in the birefringent writing recording layer is written by a single-beam nanolithography writing method or a dual-beam nanolithography writing method.
In an embodiment of the present application, the single-beam nanolithography writing method includes: the method comprises the steps of compressing the size of a diffraction-limited focusing light spot by adopting a focusing mode of a short-wavelength writing laser beam and a high-numerical-aperture objective lens so as to realize the writing of nano-scale photoetching information; the short wavelength writing laser beam acts on the birefringence writing recording layer, and the etching depth and width of the recording layer are accurately controlled by controlling the irradiation time and laser intensity of the short wavelength writing laser beam.
In an embodiment of the present application, the dual-beam nanolithography writing method includes: solid writing light beams and hollow suppression light beams with different wavelengths are adopted to simultaneously irradiate an absorption modulation layer which is formed by absorption modulation materials in a physical storage medium of the optical disk so as to realize super-resolution nano photoetching writing through an absorption modulation effect; focal planes of the solid writing light beams and the hollow suppression light beams are overlapped in space, and the light intensity of the solid writing light beams accords with Gaussian intensity distribution to write information; the light intensity of the hollow suppression light beam conforms to the annular intensity distribution so as to suppress peripheral light spots of the solid writing light beam from transmitting through the absorption modulation layer; and respectively controlling the irradiation time and the beam intensity of the solid writing beam and the hollow suppression beam to realize the accurate control of the etching depth and the etching width of the information recording layer.
In the present embodiment, the solid writing beam and the hollow suppression beam can be referred to as the solid writing beam 105 and the hollow suppression beam 106 in fig. 1.
In this embodiment, reference may also be made to the detailed description of the "writing method based on nanolithography" in the patent document with the application number of 201811383960.5 and with the application name of "optical disc reading and writing method based on nanolithography and writing control information encoding and decoding method:
the focal spot size of the solid writing beam is compressed. The beam intensity of the solid writing beam conforms to Gaussian intensity distribution, and visible, ultraviolet and deep ultraviolet continuous laser or pulse laser with a wave band between visible light and ultraviolet light can be adopted. Specifically, compressing the focal spot size of the solid writing beam can be achieved in one or two ways:
the method comprises the steps that in the first mode, a solid writing light beam and a hollow suppression light beam with different wavelengths are formed respectively, wherein the light beam intensity of the hollow suppression light beam accords with annular intensity distribution, and the central intensity tends to be zero; making focal planes of the solid writing light beam and the hollow suppression light beam coincide on the space; irradiating the overlapped light beam on a physical storage medium of an optical disc, wherein the hollow suppression light beam suppresses peripheral light spots of the solid writing light beam, for example: the hollow suppression light beam irradiates an absorption modulation layer of the optical disk physical storage medium; another example is: under the action of the hollow suppression beam, the absorption modulation layer suppresses peripheral light spots of the solid writing beam from transmitting through the absorption modulation layer, and for example: the solid writing beam in the first mode or the second mode adopts a pulse beam to realize a two-photon writing method and the like so as to compress the focal spot size of the solid writing beam; and secondly, reducing the wavelength of the solid writing light beam and/or increasing the numerical aperture of the objective lens.
In one embodiment of the present application, the birefringent material includes:
1) the film polarization material formed by the dielectric film stack is formed by coating a film by a physical vapor deposition method, and the adopted material comprises one or more of MgF2, SiO2, ZrO2, TiO2 and HfO 2;
2) organic polymer materials, which comprise any one or more of azo polymer, azo liquid crystal material, PMMA, PE, PI and polyester material;
3) a birefringent sculpturing film comprising any one or combination of more of SiO2, TiO2, and ZnS;
4) a birefringent crystal material comprising any one or a combination of calcite, lithium niobate, lithium tantalate, and barium niobate;
5) the optical rotation material changes the polarization plane when light passes through the material, and comprises one or more of quartz and optical rotation high molecular polymer.
In one embodiment of the present application, the characterization 2 is performed by one or more grooves with depth information at the fixed recording position m Carrying out storage information in a system counting mode; wherein m represents the number of the grooves, and the depth information is used for representing 2 through whether the grooves have the depth information or not m The value 1 or 0 of the stored information in the binary count mode.
In this embodiment, one or more grooves with depth information at the fixed recording position are used for characterization 2 m The storage information of the binary count system corresponds to 2 of the second embodiment m The specific content of the bit multi-level information coding can refer to a in the second embodiment described in the present application.
At the recording layer-writing fixed positions (1), (2) … (m) for the specific fixed recording position iContinuously writing Z1 with different depths by using a nano photoetching information writing method; z2 … Zm grooves with different depths corresponding to 2 m The number of bits in a binary count, such as in a trench depth Z1; z2; z3 is used for data recording, and corresponds to octal counting mode, and whether the corresponding groove is engraved or not corresponds to '0' and '1' on the digit in octal; or at fixed positions of the writing recording layer, Z1 for writing different depths is adopted; the Z2 … Zm trench is used to characterize the different stored values, i.e., corresponding to a stored value of "1, 2 … m" as described above. Therefore, in the 'diffraction limit' light spot size of the measuring light, the multi-groove continuous writing recording method can be realized, so that 2 is realized in the single-point recording range of the original optical disc m The writing of the bit photoetching information reduces the size of a recording light spot and greatly improves the storage dimension, thereby improving the storage capacity of the optical disk.
In another embodiment of the present application, the data dimension X of the storage information is represented by a plurality of depth information on each of the trenches, so as to realize X m Carrying out storage information in a system counting mode; characterizing X by different depth values in the depth information on the trench m And carrying out data dimension X of the storage information in a binary counting mode.
In this embodiment, one or more grooves with depth information at the fixed recording position are used to characterize X m The storage information of the binary count system corresponds to X of the second embodiment m The specific content of the bit multi-level information coding can refer to B in the second embodiment described in the present application.
Step S302: and linear superposed laser beams with different polarization directions, which are reflected by the birefringent writing recording layer, of the linear bias laser beam are obtained.
Step S303: the linearly-superposed laser is split by a polarization beam splitter to respectively obtain an S component and a P component of the laser
Step S304: and measuring the intensities of the S component and the P component so as to read out corresponding stored information.
Third embodiment
In the present embodiment, steps S302 to S304 are the main processes of the polarization balance measurement reading method. The principle of the polarization balance measurement reading method is shown in fig. 4. As shown, a linearly polarized beam 401, with its polarization direction fixed at 402, is incident perpendicular to the optical axis of the birefringent material 403, is split into two beams, o and e, due to the birefringence effect, and is not spatially separated due to the incident perpendicular to the optical axis, as shown at 404; the propagation distance in the birefringent material is d, and the absorptance of the birefringent material for the S and P polarization components of the o light and the e light is different, so that the polarizations of the o light and the e light are changed by a certain angle, as shown in 405; the polarization direction of the light beam affected by the birefringent material is changed, as shown in 406, the polarization beam splitter 407 performs beam splitting measurement on the outgoing light beam, so as to obtain the intensity information of the S and P components of the outgoing light beam, thereby obtaining the polarization angle change of the outgoing light beam, and solving the thickness d of the birefringent material.
In this embodiment, the second embodiment 2 is combined m The principle of the polarization balance measurement method described in the present application is further explained by the bit multi-order information encoding and writing method. As shown in FIG. 5, a light beam 502 is irradiated onto a birefringent writing recording layer 501 with a polarization direction 503 through different thicknesses d m ＝l-Z m In which Z is m Is the depth information of the groove, is reflected by the reflecting layer and then propagates in the birefringent material m ＝l-Z m After emerging, i.e. travelling for a distance of 2d in the birefringent material m Then, the polarization direction of the emergent light beam is as shown in 504, 505 and 506, the polarization direction is deflected, the included angles corresponding to the S component are α, β and γ, at this time, the reflected light is collected, and the laser linear superposition with different polarization directions is obtained; the collected laser light is split by a polarization beam splitter, and S, P components of the collected laser light are obtained respectively. Therefore, the magnitude of the S, P component is changed compared to that obtained at the time of the balance measurement, thereby reversely solving the stored data information.
Specifically, in an embodiment of the present application, the method for measuring the intensities of the S component and the P component for reading out the corresponding stored information includes:
the intensities of the S-component and P-component corresponding to one or more of the trenches at the fixed recording location are expressed as:
Figure BDA0001963959030000121
Figure BDA0001963959030000122
Wherein i represents an included angle between the polarization direction of the line bias laser reflected after the action of the un-written birefringent layer and the S component; α, β, γ.. indicate the included angles between the S components and the different polarization directions of the line bias laser reflected by the birefringent layer after the action of the birefringent layer; m represents the number of the trenches having the depth information; a 1 or 0 in the matrix represents whether the depth information is on the trench.
In another embodiment of the present application, the method for measuring the intensities of the S component and the P component for reading out the corresponding stored information comprises:
the intensities of the S-component and P-component corresponding to one or more grooves with different depth information at the fixed recording location are represented as:
Figure BDA0001963959030000123
Figure BDA0001963959030000124
wherein i represents an included angle between the polarization direction of the linear bias laser reflected after the action of the un-written birefringent layer and the S component; the included angles between the S component and different polarization directions of the linear bias laser reflected by the birefringent layer after the linear bias laser acts on the birefringent layer are expressed; m represents the number of the trenches having the depth information; 0-x in the matrix are represented as different writing depth values in said depth information on said groove.
The polarization balance measurement reading method has high storage precision and resolution capability, is beneficial to improving the storage dimensionality during multi-dimensional information storage, and can realize the multi-order optical information storage with larger m value.
In an embodiment of the present application, the number m of the grooves is associated with a resolution of a polarization balance measurement method, and the stronger the resolution, the greater the number of the grooves is determined.
Specifically, the determination of the multi-order bit number in the storage coding method described in the present application depends on the resolution obtained by polarization balance measurement, and the stronger the resolution is, the higher the storage order in the corresponding multi-order storage method is, so that the larger the capacity of the storage information is.
In an embodiment of the present invention, the wavelength of the linearly polarized laser with a fixed polarization direction is selected to have a low absorption rate for the absorption modulation layer, so as to avoid the same wavelength as the write laser wavelength.
In particular, it is avoided here that the read-out light wavelength and the write-in light wavelength are the same, which would otherwise be influenced by the absorption modulation layer, while the dichroic mirror may be unusable if the wavelengths are the same.
Fourth embodiment
The optical disc structure of the erasable ultra-high density optical disc suitable for the erasable nano writing and reading method described in this application is shown in fig. 1, and the corresponding optical disc physical storage medium structure is characterized in that:
1) a protective layer 101 that allows the disc to withstand frequent use, fingerprints, scratches and dirt, thereby ensuring the storage quality and data security of the disc;
2) An absorption modulation layer 102, the layer of material has absorption modulation characteristics, the layer thickness is less than 500nm, the material of the absorption modulation layer includes diaryl ethylene, fulgide material, azide material, but is not limited to these;
3) the birefringent writing recording layer 103 is used for writing and recording information, and is characterized in that the birefringent writing recording layer is made of birefringent material, can erase optical storage information by uniform illumination and heating, can be stably stored, and is made of selected materials such as single-photorefractive ion doping, double-photorefractive ion doping and the like, such as lithium niobate crystals with single iron, copper, manganese, cerium, titanium and terbium, iron-doped lithium manganese niobate crystals and the like, but is not limited to the above;
4) the reflective layer 104, which is used to improve the reflectivity of laser light and facilitate the reflection measurement of polarization balance information, is characterized by a material with high reflectivity, mainly including a metal material, etc., but not limited thereto.
In another embodiment, further, a transition protection layer of less than 10nm may be added between the absorption modulation layer 102 and the birefringent writing recording layer 103 as required to protect the recording layer from the absorption modulation layer.
In combination with the physical storage structure of the optical disc, the main processes of the erasable nanometer writing and reading method are as follows:
As shown in fig. 6, an erasable nano-writing and reading method in an embodiment of the present application is shown. As shown, the method comprises:
step S601: compressing the focal spot size of the solid writing beam;
step S602: the solid writing light beam acts on the writing birefringence writing recording layer, so that the writing birefringence writing recording layer material generates a photoinduced birefringence effect, and the reversible refractive index change of the writing light beam acting area material is generated;
step S603: controlling the size of a recording spot at a fixed recording position on the birefringent writing recording layer by controlling the beam intensity and the action time of the solid writing beam;
step S604: one or more of the fixed recording positions having different recording dot sizes are recorded on the birefringent writing recording layer made of a light-induced birefringent material by irradiating the birefringent writing recording layer with a linearly polarized laser of a fixed polarization direction.
In this embodiment, steps S601 to S604 constitute another optical disc writing method based on nanolithography, which is mainly different from the "nanolithography-based writing method" described in the first embodiment of the present application in that: the optical disc writing method based on nanolithography in steps S601 to S604 mainly records one or more fixed recording positions with different recording dot sizes on the birefringent writing recording layer according to the beam intensity and acting time of the light beam, while the "nanolithography-based writing method" described in the first embodiment of the present application mainly performs information writing (groove burning) on the birefringent writing recording layer by the light beam (smaller beam size) compressed by the absorption modulation layer.
In short, the former stores information by changing the refractive index and size of the recording point position on the birefringent writing recording layer through a light beam, and the latter stores information by burning different depths of information on the birefringent writing recording layer through a light beam.
Step S605: linear superposed laser with different polarization directions reflected by the birefringence writing recording layer is obtained;
step S606: splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser;
step S607: and measuring the intensities of the S component and the P component so as to read out the corresponding stored information.
In this embodiment, steps S605 to S607 are a reading method based on the writing method formed in steps S601 to S604, which is similar to the principle of the polarization balance measurement reading method described in fig. 3, but in the erasable nano writing and reading method, the storage or writing form of the read storage information is different (being a recording dot, not a groove etched).
In this embodiment, although it has been used to record one or more fixed recording positions with different recording spot sizes on the birefringent writing recording layer by the beam intensity and the acting time of the beam, the storage capacity and density are not ideal.
By compressing the size of the focal spot of the solid writing beam, the reading and writing of the information recording point with the nanometer size can be realized. Simultaneous binding 2 m The bit multi-level information coding method enables the optical disc storage to have higher storage density and storage capacity and faster read-write speed.
Fifth aspect of the inventionExamples
In an embodiment of the present application, the writing method of the erasable ultra-high density optical disc in the present application adopts 2 m The bit multi-level information coding method and the nanometer photo-induced birefringence method are combined, wherein 2 m The bit multi-level information coding method is characterized in that:
for a specific information recording point i, recording information recording points A1 of different sizes by using a writing method of an erasable ultra-high density optical disc at birefringent writing recording layer fixing positions (1), (2) … (m); a2 … Am, different recording dot sizes corresponding to 2 m The number of bits in a binary counting scheme, such as recording the different size sizes of dots a 1; a2; a3 is used for data recording, and corresponds to octal counting mode, and whether the fixed position of the recording point is inscribed or not corresponds to '0' and '1' on the digit in the octal; or at a recording layer fixing position, a different information recording dot size a 1; a2 … Am to characterize the different stored values, i.e. corresponding to a stored value of "1, 2 … m" as above. Therefore, in the 'diffraction limit' spot size of the measuring light, the multi-groove continuous writing recording method can be realized, so that 2 is realized in the single-point recording range of the original optical disc m The writing of the bit photoetching information reduces the size of a recording light spot and greatly improves the storage dimension, thereby improving the storage capacity of the optical disk.
For example, as shown in FIG. 7, where 2 m The bit multi-level information coding method is characterized in that: taking m as an example of 3, continuous information dot writing with different recording dot sizes is carried out at (1), (2) and (3) at the fixed recording dot position 705 on the birefringence writing recording layer, wherein writing at the position corresponding to (m) represents that the recording dot at the position is '1', otherwise, the recording dot is '0', and different (m) corresponds to 2 m Different number of bits in the bit encoding; at this point, the information recording at 705 is completed, and then the mobile terminal moves to the next fixed position 706, and the above process is repeated to complete the data recording; by analogy, the whole process of data recording is completed, thereby realizing 2 within the diffraction limit 704 3 Storing the order data; or recording of lithographic information at recording spot positions 201, 202, 203 as in fig. 2, the recording spot sizes at (1) are respectively,respectively corresponding to the (1) recorded data "0, 1, 2, 3"; (2) the recording dot sizes at the positions are respectively corresponding to the recording data of '0, 1, 2, 3' at the position (2); (3) the recording dot sizes at (3) are respectively corresponding to the recording data "0, 1, 2, 3". Thereby achieving (2) within diffraction limit 204 2 ) 3 And storing the order data.
In an embodiment of the present application, the stored information on the birefringent writing recording layer is erased by changing the refractive index of the birefringent writing recording layer by light or heat.
In this embodiment, the writing method in the fourth embodiment mainly changes the refractive index or the size of the recording spot at the fixed recording position on the birefringent writing recording layer through the light beam, and does not cause irreversible damage to the recording layer, so that it can also erase the stored information by changing the refractive index or the size of the recording spot, thereby implementing erasable data storage of the optical disc, and being capable of repeating information recording for many times.
In an embodiment of the application, the method for changing the refractive index of the birefringent writing recording layer by light irradiation or heating further includes: the illumination intensity or the illumination time is adjusted to realize accurate control; or, the precise control can be realized by adjusting the heating temperature or the heating time.
In an embodiment of the present application, the birefringent writing recording layer material includes:
1) organic polymer material, which comprises any one or more combination of azo polymer, azo liquid crystal material, PMMA, PE, PI and polyester material;
2) The metal ion doped lithium niobate crystal material comprises one or more of ferromanganese double doping, Mg and Fe.
To achieve the above and other related objects, the present application provides a polarization balance measurement reading device, comprising: the polarization module is used for irradiating a fixed recording position etched with one or more grooves with depth information on a birefringent writing recording layer made of a birefringent material by linear polarization laser with a fixed polarization direction; the measuring module is used for obtaining linear superposed laser of different polarization directions reflected by the birefringence writing recording layer through the linear polarized laser; splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser; and measuring the intensities of the S component and the P component so as to read out corresponding stored information.
In an embodiment of the present application, the polarization balance measurement reading method as described in fig. 3 can be implemented by using modules in cooperation.
A single-beam nanolithography writing method and a dual-beam nanolithography writing method corresponding to the nanolithography-based writing method in the first embodiment, respectively. The polarization balance measurement reading device is subdivided into a single-beam writing polarization balance measurement reading device and a double-beam writing polarization balance measurement reading device. The polarization balance measurement reading device can be used for realizing the polarization balance measurement reading method corresponding to the third embodiment.
Fig. 8A is a schematic structural diagram of a single-beam writing polarization balance measurement reading apparatus according to an embodiment of the present application. Fig. 8B is a schematic structural diagram of a dual-beam writing polarization balance measurement reading apparatus according to an embodiment of the present application.
The specific structure of the corresponding polarization module and the corresponding measurement module in the polarization balance measurement reading device is as follows:
in an embodiment of the present application, the optical path module includes: a linear polarization laser 801, a first coupling lens 802, a polarization maintaining optical fiber 803, a first collimating lens 804, an 1/2 lambda plate 805, a polarization compensator 806, a dichroic mirror 807 and a high power objective lens 808;
the linear polarization laser 801 is used for emitting linear polarization laser with stable power and linear polarization direction;
the first coupling lens 802, the polarization maintaining fiber 803, the first collimating lens 804, the 1/2 lambda plate 805, the polarization compensator 806 and the dichroic mirror 807 are sequentially arranged from bottom to top; wherein the first coupling lens 802 is used for focusing the line bias laser; the polarization maintaining fiber 803 is used for ensuring the polarization direction of the linear polarization laser and filtering and shaping the light beam; the collimating lens 804 is used for ensuring the line bias laser light to be collimated; the 1/2 lambda plate 805 is used for adjusting the polarization direction of the linearly polarized laser; the polarization compensator 806 is used for compensating the polarization change of the linearly polarized laser;
The dichroic mirror 807 arranged at a certain angle to the exit direction of the linearly polarized laser light, for changing the emission path of the linearly polarized laser light;
the high power objective lens 808 is disposed on the path of the beam after the emission path is changed by the dichroic mirror, and is used for focusing the line bias laser on the fixed recording position of the birefringent writing recording layer 810 (optical disc storage medium structure 809) etched with grooves with different thicknesses
In an embodiment of the present application, the measurement module includes: a high power objective lens 808, a beam splitter 811, a polarization beam splitter 812, a first focusing lens 813, a second focusing lens 814, a first detector 815, a second detector 816;
the high power objective lens 808 and the beam splitter 811 are sequentially arranged on a path of the line bias laser reflected by the birefringent writing recording layer 810; the high power objective lens 808 is configured to collect the emitted linear polarization laser light to obtain linear superposition laser light with different polarization directions; the beam splitter 811 is configured to split the collected linearly polarized laser light and change the collected linearly polarized laser light to the polarization beam splitter 812;
the polarization beam splitter 812 is arranged on a path of which the collection path is changed by the beam splitter 811, and the first focusing lens 813 and the first detector 815 are respectively arranged on a first path of the polarization beam splitter 812 in sequence; the second focusing lens 814 and the second detector 816 are sequentially disposed on the second path of the polarization beam splitter 812, respectively;
The polarization beam splitter 812 is configured to split the linearly-superimposed laser into an S component and a P component; the first focusing lens 813, and the second focusing lens 814 are used to focus the S component or the P component; the first detector 815 and the second detector 816 are used to measure the intensity of the S component or the P component for reading out the corresponding stored information.
In this embodiment, after the collected line bias laser light passes through the first focusing lens 813 and the second focusing lens 814, a multimode fiber may be added to collect the line bias laser light again, and the first detector 815 and the second detector 816 are used to perform beam intensity measurement, so as to improve the longitudinal resolution of the polarization balance measurement method.
In an embodiment of the present application, the structure of the polarization balance measurement reading apparatus for single beam writing in fig. 8A further includes: and a single beam writing module.
The single beam writing module comprises: a writing laser 817, a second coupling lens 818, a μm-level aperture 819, a second collimating lens 820, and a mirror 821.
In an embodiment of the present application, the structure of the dual-beam writing polarization balance measurement reading apparatus in fig. 8B further includes: a dual beam writing module.
The dual beam writing module includes: a suppressed laser 817, a writing laser 818, a second coupling lens 819/820, a μm-order pinhole 821/822, a second collimating lens 823/824, a vortex phase plate 825, and a mirror 826/827.
Sixth embodiment
Corresponding to the single-beam nanolithography writing method based on the nanolithography writing method in the first embodiment and the polarization balance measurement reading method in the third embodiment of the present application, the application scenarios of the single-beam writing polarization balance measurement reading device in fig. 8A are as follows:
1) the writing light beam is emitted from a writing laser 817, is focused by a second coupling lens 818, and is filtered by selecting a corresponding μm-level aperture 819 according to the focal length and NA of the second coupling lens 818, or selecting a single-mode fiber to replace the μm-level aperture 819;
2) after being collimated and expanded by a second collimating lens 820 and reflected by a reflector 821, a divergent light beam of the writing light beam after spatial filtering enters a high-power objective lens 808, a focus 710 acts on a birefringent writing recording layer 810 of an optical disc storage medium structure 809, the birefringent writing recording layer 810 is subjected to a photoetching information writing process, and the etching depth and the etching width of the information recording layer are accurately controlled by controlling the irradiation time and the light beam intensity of the writing light beam;
3) The linearly polarized laser 801 emits linearly polarized laser with a linear polarization direction, the linearly polarized laser is focused by the first coupling lens 802 and coupled into the polarization maintaining fiber 803 to ensure the polarization direction of an emitted light beam, and a divergent light beam emitted from the polarization maintaining fiber 803 is collimated by the first collimating lens 804, passes through the 1/2 lambda plate 805 and the polarization compensator 806 and is distributed to adjust the polarization direction of the light beam and compensate polarization change caused by an optical element;
4) the modulated linearly polarized light beam acts on the birefringent writing recording layer 810, is split by the beam splitter 811 after being collected by the high power objective lens 808 and then is split into S and P components by the polarization beam splitter 812, and after being focused by the first focusing lens 813 and the second focusing lens 814 respectively, intensity measurement is performed by the first detector 815 and the second detector 816, and the intensity balance calculation is performed on the measured result by the computer to reversely solve the writing data information.
Seventh embodiment
Corresponding to the dual-beam nanolithography writing method based on the nanolithography writing method in the first embodiment and the polarization balance measurement reading method in the third embodiment of the present application, the application scenarios of the dual-beam writing polarization balance measurement reading device in fig. 8B are as follows:
1) The writing light beam is emitted from the writing laser 818, is focused by the second coupling lens 820, and is filtered by selecting the corresponding mu m-level pinhole 822 according to the focal length and NA of the second coupling lens 820, or selecting a single mode fiber to replace the mu m-level pinhole 822;
2) the suppression light beam is emitted from the suppression laser 817, is focused by the second coupling lens 819, and is filtered by selecting the corresponding μm-level aperture 821 according to the focal length and NA of the second coupling lens 819, or selecting a single-mode fiber to replace the aperture 605;
3) the divergent light beam of the writing light beam after spatial filtering is collimated and expanded by the second collimating lens 824, the collimated light beam is reflected by the reflector 827 and then enters the high-power objective lens 808, and the objective lens focuses to form a solid light beam 828 with the size of the diffraction limit dimension;
4) the divergent light beam after the suppression light beam is spatially filtered is collimated and expanded by the second collimating lens 823, the collimated light beam passes through the vortex phase plate 824 to generate a laser beam with a phase from 0 to pi, the laser beam passes through the reflector 826 and the reflector 827 and then enters the high power objective 808, and the light beam is focused by the objective to form a hollow light beam 829 with a central intensity of approximately zero;
5) by taking the hollow light beam 829 as a reference, adjusting the front and back positions of the second collimating lens 823 to adjust the divergence of the solid light beam 828, and adjusting the mirror 827 to adjust the incident angle of the solid light beam 828, so that the solid writing light beam 828 and the hollow light beam 829 spatially coincide and act on the physical storage medium structure 809 of the optical disc, and performing a lithography information writing process on the birefringent writing recording layer 810, and by controlling the irradiation time and the light beam intensity of the writing light beam and the suppression light beam, accurately controlling the etching depth and the etching width of the information recording layer;
6) A linearly polarized laser with a linear polarization direction is emitted by a linearly polarized laser 801, is focused by a first coupling lens 802, is coupled into a polarization maintaining fiber 803 to ensure the polarization direction of the emitted light beam, and is collimated by a first collimating lens 804, and then passes through an 1/2 lambda plate 805 and a polarization compensator 806, and is distributed to adjust the polarization direction of the light beam and compensate the polarization change caused by an optical element;
7) the modulated linearly polarized light beam acts on the birefringent writing recording layer 810, is split by the beam splitter 811 after being collected by the high power objective lens 808 and then is split into S and P components by the polarization beam splitter 812, and after being focused by the first focusing lens 813 and the second focusing lens 814 respectively, intensity measurement is performed by the first detector 815 and the second detector 816, and the intensity balance calculation is performed on the measured result by the computer to reversely solve the writing data information.
Fig. 9 is a block diagram of an erasable nano-writing and reading apparatus according to an embodiment of the present application. As shown, the apparatus 900 comprises:
a writing module 901 for compressing the focal spot size of the solid writing beam; the solid writing light beam acts on the writing birefringence writing recording layer, so that the writing birefringence writing recording layer material generates a photoinduced birefringence effect, and the reversible refractive index change of the writing light beam acting area material is generated; controlling the size of a recording spot at a fixed recording position on the birefringent writing recording layer by controlling the beam intensity and the action time of the solid writing beam;
A reading module 902, configured to record one or more fixed recording positions with different recording dot sizes on the birefringent writing recording layer made of a photo-induced birefringent material by irradiating a linearly polarized laser with a fixed polarization direction; linear superposed laser with different polarization directions reflected by the birefringence writing recording layer is obtained; splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser; and measuring the intensities of the S component and the P component so as to read out the corresponding stored information.
It is understood that the erasable nano writing and reading apparatus 900 can implement the erasable nano writing and reading method as described in fig. 6 through the operation of each module.
To sum up, the polarization balance measurement reading method and device based on the nano-lithography optical disc of the present application have the following beneficial technical effects:
1. method for writing nano photoetching information in and 2 m The bit multi-order information coding method is combined, the information storage density is improved by reducing the size of a recording light spot through a nano photoetching information writing method, and 2 different bit information is characterized by using different groove depths m The information storage dimensionality is improved by the bit multi-level information coding method, so that the storage density and the storage capacity of the optical disk information storage are greatly improved.
2. Compared with the existing blue-ray disc which stores data by using the refractive index change of materials, the data storage method has higher stability and is more suitable for long-term storage of information.
3. The material absorption modulation characteristic is utilized to compress the focused light spot of the etching beam, and the etching depth and the etching width are accurately controlled by controlling the intensity and the acting time of the etching beam and the inhibiting beam, so that the nano-sized photoetching information writing process is realized.
4. The optical disk information storage recording layer is made of the birefringent material, and compared with other optical disks, the stability of the optical disk information storage recording layer is higher, and the long-term storage of stored information is facilitated.
5. The optical refraction material is used for writing photoetching information, and optical storage recording information can be erased by methods of uniform illumination or heating and the like, so that the erasable repeated writing and recording of the optical disk are realized.
6. The information reading is carried out on the writing information by utilizing a polarization balance measurement reading method, so that the method has higher sensitivity, response speed and resolution capability, and can realize multi-order storage of more dimension information.
The above embodiments are merely illustrative of the principles and utilities of the present application and are not intended to limit the present application. Any person skilled in the art can modify or change the above-described embodiments without departing from the spirit and scope of the present application. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical concepts disclosed in the present application shall be covered by the claims of the present application.

Claims (17)

1. A polarization balance measurement reading method, the method comprising:
irradiating a fixed recording position etched with one or more recording points on a birefringent writing recording layer made of birefringent material by linear polarization laser with a fixed polarization direction; each recording point is etched with a plurality of grooves with depth information; wherein each recording point records one datum; each groove corresponds to a different number of bits of the data;
linear superposed laser with different polarization directions reflected by the birefringence writing recording layer is obtained;
splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser;
And measuring the intensities of the S component and the P component so as to read out corresponding stored information.
2. The reading method for polarization balance measurement according to claim 1, wherein the storage information of 2-ary counting mode is represented by grooves each having depth information on the recording points; wherein m represents the number of the grooves, and the number of the storage information which represents a 2-system counting mode is 1 or 0 according to whether the depth information exists on the grooves.
3. The polarization balance measurement reading method according to claim 1, wherein a plurality of depth information on each groove is used to characterize a data dimension x of the stored information, so as to realize the stored information in an x-ary counting manner; and the data dimension x of the storage information in an x-system counting mode is represented by different depth values in the depth information on the groove.
4. The polarization balance measurement reading method according to claim 2 or 3, wherein the number m of the grooves is associated with a resolving power of a polarization balance measurement method, and the stronger the resolving power, the larger the number of the grooves is determined.
5. The polarization balance measurement reading method of claim 1, wherein the wavelength of the fixed polarization direction linearly polarized laser light is selected to have a low absorption to the absorption modulation layer to avoid being the same as the write laser wavelength.
6. The polarization balance measurement reading method of claim 1, wherein the birefringent material comprises any one of:
1) the film polarization material formed by the dielectric film stack is formed by coating a film by a physical vapor deposition method, and the adopted material comprises one or more of MgF2, SiO2, ZrO2, TiO2 and HfO 2;
2) organic polymer materials, which comprise any one or more of azo polymer, azo liquid crystal material, PMMA, PE, PI and polyester material;
3) a birefringent sculpturing film comprising any one or combination of more of SiO2, TiO2, and ZnS;
4) a birefringent crystal material comprising any one or a combination of calcite, lithium niobate, lithium tantalate, and barium niobate;
5) the optical rotation material is used for changing the polarization plane when light passes through the optical rotation material, and comprises one or more of quartz and optical rotation high molecular polymer.
7. The polarization balance measurement reading method according to claim 1, wherein the stored information stored in the birefringent writing recording layer is written by a single beam nanolithography writing method or a dual beam nanolithography writing method.
8. The polarization balance measurement reading method of claim 7, wherein the single beam nanolithography writing method comprises:
the method comprises the steps of compressing the size of a diffraction-limited focusing light spot by adopting a focusing mode of a short-wavelength writing laser beam and a high-numerical-aperture objective lens so as to realize the writing of nano-scale photoetching information;
the short wavelength writing laser beam acts on the birefringence writing recording layer, and the etching depth and width of the recording layer are accurately controlled by controlling the irradiation time and laser intensity of the short wavelength writing laser beam.
9. The polarization balance measurement reading method of claim 7, wherein the dual-beam nanolithography writing method comprises:
solid writing light beams and hollow suppression light beams with different wavelengths are adopted to simultaneously irradiate an absorption modulation layer which is formed by absorption modulation materials in a physical storage medium of the optical disk so as to realize super-resolution nano photoetching writing through an absorption modulation effect;
focal planes of the solid writing light beams and the hollow suppression light beams are overlapped in space, and the light intensity of the solid writing light beams accords with Gaussian intensity distribution to write information; the light intensity of the hollow suppression light beam conforms to the annular intensity distribution so as to suppress peripheral light spots of the solid writing light beam from transmitting through the absorption modulation layer;
And respectively controlling the irradiation time and the beam intensity of the solid writing beam and the hollow suppression beam to realize the accurate control of the etching depth and the etching width of the information recording layer.
10. An erasable nano writing and reading method, the method comprising:
compressing the focal spot size of the solid writing beam;
the solid writing light beam acts on the writing birefringence writing recording layer, so that the writing birefringence writing recording layer material generates a photoinduced birefringence effect, and the reversible refractive index change of the writing light beam acting area material is generated;
controlling the beam intensity and action time of the solid writing beam to control the size of a plurality of grooves in one or a plurality of recording points at fixed recording positions on the birefringent writing recording layer;
irradiating a fixed recording position on which one or more recording points are recorded on the birefringent writing recording layer made of a light-induced birefringent material by a linear polarization laser with a fixed polarization direction; each recording point is etched with a plurality of grooves with depth information; wherein each recording point records one datum; each groove corresponds to a different number of bits of the data;
linear superposed laser with different polarization directions reflected by the birefringence writing recording layer is obtained;
Splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser;
and measuring the intensities of the S component and the P component so as to read out corresponding stored information.
11. The erasable nano writing and reading method according to claim 10, wherein the stored information on the birefringent writing recording layer is erased by changing a refractive index of the birefringent writing recording layer by light or heat.
12. The erasable nano writing and reading method according to claim 10, wherein the birefringent writing recording layer material has a photo-induced birefringence property, which includes any one of the following:
1) organic polymer material, which comprises any one or more combination of azo polymer, azo liquid crystal material, PMMA, PE, PI and polyester material;
2) the metal ion doped lithium niobate crystal material comprises one or more of ferromanganese double doping, Mg and Fe.
13. The erasable nano writing and reading method according to claim 11, wherein the method of changing the refractive index of the birefringent writing recording layer by light or heat further comprises: the illumination intensity or the illumination time is adjusted to realize accurate control; or, the precise control can be realized by adjusting the heating temperature or the heating time.
14. A polarization balance measurement reading device, comprising:
a polarization module for irradiating a fixed recording position where one or more recording points are recorded on the birefringent writing recording layer made of a light-induced birefringent material by a linear polarization laser with a fixed polarization direction; a plurality of grooves with depth information are etched on each recording point; wherein each recording point records one datum; each groove corresponds to a different number of bits of the data;
the measuring module is used for obtaining linear superposed laser of different polarization directions reflected by the birefringence writing recording layer through the linear polarized laser; splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser; and measuring the intensities of the S component and the P component so as to read out corresponding stored information.
15. The polarization balance measurement reading apparatus of claim 14, wherein the polarization module comprises: the device comprises a linear polarization laser, a first coupling lens, a polarization maintaining optical fiber, a first collimating lens, an 1/2 lambda plate, a polarization compensator, a dichroic mirror and a high-power objective lens;
the linear polarization laser is used for emitting linear polarization laser with stable power and linear polarization direction;
The first coupling lens, the polarization-maintaining optical fiber, the first collimating lens, the 1/2 lambda plate, the polarization compensator and the dichroic mirror are sequentially arranged from bottom to top; wherein the first coupling lens is used for focusing the linearly polarized laser; the polarization maintaining optical fiber is used for ensuring the polarization direction of the linear polarization laser and filtering and shaping the light beam; the collimating lens is used for ensuring the collimation of the line bias laser; the 1/2 lambda plate is used for adjusting the polarization direction of the linearly polarized laser; the polarization compensator is used for compensating the polarization change of the linearly polarized laser;
the dichroic mirror is arranged at a certain angle with the emergent direction of the line bias laser and is used for changing the emitting path of the line bias laser so as to ensure that the line bias laser is incident and focused along the optical axis of the high-power objective;
the high power objective lens is arranged on a path of the birefringent writing recording layer after the emission path of the birefringent writing recording layer is changed, and is used for focusing the line bias laser on a fixed recording position of the birefringent writing recording layer, wherein grooves with different thicknesses are etched on the fixed recording position.
16. The polarization balance measurement reading apparatus of claim 14, wherein the measurement module comprises: the high-power objective lens, the beam splitter, the polarization beam splitter, the first focusing lens, the second focusing lens, the first detector and the second detector;
The high power objective lens and the beam splitter are sequentially arranged on a path of the line bias laser reflected by the birefringent writing recording layer; the high-power objective lens is used for collecting the linear bias laser to obtain linear superposed laser in different polarization directions; the beam splitter is used for splitting the collected linear polarization laser and changing the collected linear polarization laser to the polarization beam splitter;
the polarization beam splitter is arranged on a path of which the collection path is changed by the beam splitter, and the first focusing lens and the first detector are respectively and sequentially arranged on a first path of the polarization beam splitter; the second focusing lens and the second detector are sequentially arranged on a second path of the polarization beam splitter respectively;
the polarization beam splitter is used for splitting the linear superposition laser into an S component and a P component; the first focusing lens and the second focusing lens are used for focusing the S component or the P component; the first detector and the second detector are used for measuring the intensity of the S component or the P component so as to read out corresponding stored information.
17. An erasable nano-writing and reading apparatus, the apparatus comprising:
A writing module for compressing the focal spot size of the solid writing beam; the solid writing light beam acts on the writing birefringence writing recording layer, so that the writing birefringence writing recording layer material generates a photoinduced birefringence effect, and the reversible refractive index change of the writing light beam acting area material is generated; controlling the size of a recording spot at a fixed recording position on the birefringent writing recording layer by controlling the beam intensity and the action time of the solid writing beam;
the reading module is used for irradiating a fixed recording position, in which one or more recording points are recorded, on the birefringent writing recording layer made of the photoinduced birefringent material through linear polarization laser with a fixed polarization direction; each recording point is etched with a plurality of grooves with depth information; wherein each recording point records one datum; each groove corresponds to a different number of bits of the data; linear superposed laser with different polarization directions reflected by the birefringence writing recording layer is obtained; splitting the linearly superposed laser by a polarization beam splitter to respectively obtain an S component and a P component of the laser; and measuring the intensities of the S component and the P component so as to read out corresponding stored information.
CN201910093645.7A 2019-01-30 2019-01-30 Polarization balance measurement reading method and device based on nano photoetching optical disk Active CN111508534B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910093645.7A CN111508534B (en) 2019-01-30 2019-01-30 Polarization balance measurement reading method and device based on nano photoetching optical disk

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910093645.7A CN111508534B (en) 2019-01-30 2019-01-30 Polarization balance measurement reading method and device based on nano photoetching optical disk

Publications (2)

Publication Number Publication Date
CN111508534A CN111508534A (en) 2020-08-07
CN111508534B true CN111508534B (en) 2022-07-29

Family

ID=71863919

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910093645.7A Active CN111508534B (en) 2019-01-30 2019-01-30 Polarization balance measurement reading method and device based on nano photoetching optical disk

Country Status (1)

Country Link
CN (1) CN111508534B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113538483B (en) * 2021-06-28 2022-06-14 同济大学 Coding and decoding method and measuring method of high-precision close-range photogrammetry mark

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1577545A (en) * 2003-07-25 2005-02-09 三星电子株式会社 Compatible optical pickup and optical recording and/or reproducing apparatus employing the same
CN1967685A (en) * 2005-03-08 2007-05-23 北京保利星数据光盘有限公司 Manufacturing method of multistage CDROM
CN101136215A (en) * 2007-10-18 2008-03-05 清华大学 Master disk of multiple ranks runlength limited read-only optical disc and writing and recording method thereof

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6552317B1 (en) * 1999-06-16 2003-04-22 Kabushiki Kaisha Sankyo Seiki Seisakusho Optical pickup device
CN1212614C (en) * 2003-04-18 2005-07-27 清华大学 Method of multi module optical storage and structure of multi module read-only optical disk based on birfringence principle
CN102543110B (en) * 2012-02-24 2015-07-08 华中科技大学 Multi-dimensional optical storage disc and data read-out method thereof
CN108320758B (en) * 2018-02-02 2019-12-20 中国科学院上海光学精密机械研究所 Reversible phase-change material high-density storage device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1577545A (en) * 2003-07-25 2005-02-09 三星电子株式会社 Compatible optical pickup and optical recording and/or reproducing apparatus employing the same
CN1967685A (en) * 2005-03-08 2007-05-23 北京保利星数据光盘有限公司 Manufacturing method of multistage CDROM
CN101136215A (en) * 2007-10-18 2008-03-05 清华大学 Master disk of multiple ranks runlength limited read-only optical disc and writing and recording method thereof

Also Published As

Publication number Publication date
CN111508534A (en) 2020-08-07

Similar Documents

Publication Publication Date Title
US6009065A (en) Optical pickup for 3-D data storage reading from the multilayer fluorescent optical disk
US8169876B2 (en) Optical information recording method, optical information reproducing method, optical information recording apparatus and optical information reproducing apparatus
US6867408B1 (en) Erasable/rewritable optical data storage with photorefractive polymers
US20070242592A1 (en) Three-dimensional optical memory
JPH11508719A (en) Optical storage device
US8503279B2 (en) Six-dimensional optical storage method and apparatus
US8395984B2 (en) Multilevel data structure
US8031577B2 (en) Optical information recording/reproducing device
TW501120B (en) Optical recording medium and recording and/or reproducing method and apparatus employing the optical recording medium
US20010038596A1 (en) Multi-wavelength optical disc, apparatus and method for reading and writing signal therefor
CN111508534B (en) Polarization balance measurement reading method and device based on nano photoetching optical disk
CN111508533B (en) Nano photoetching-based optical disk and physical storage medium structure and writing and reading method thereof
CN111462780B (en) Method and device for reading and writing information of fluorescent optical disc based on nano photoetching
WO2004036569A1 (en) Information recording medium, process for producing the same and optical information recording and reproducing device
CN111199753B (en) Optical disk read-write method based on nano photoetching and write control information coding and decoding method
KR100970728B1 (en) Super resolution information storage medium and method for developing C/N of the same
CN113838486A (en) Method and device for writing coding information and reading interference measurement of nano-writing optical disk
Vedavathi et al. STUDY OF DEVELOPMENT ISSUES IN 3D OPTICAL STORAGE DEVICES
KR100604027B1 (en) Writing/Reading apparatus and method for phase change disk
Mai et al. Multiwavelength photochromic storage system and experiment
Orlic et al. Microholographic multilayer recording at DVD density
Qi et al. Experimental study on reading and writing characteristics of three-wavelength photochromic storage material
Jiqi et al. Analysis and experiments of readouts of photochromic disks
CA2804676A1 (en) Six-dimensional multilayer optical storage device
Xu et al. Three-dimensional digital storage technology

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant