+

WO2002047012A2 - Procede permettant l'enregistrement/la recuperation de donnees par polarisation sur des supports de donnees optiques luminescents - Google Patents

Procede permettant l'enregistrement/la recuperation de donnees par polarisation sur des supports de donnees optiques luminescents Download PDF

Info

Publication number
WO2002047012A2
WO2002047012A2 PCT/IL2001/001130 IL0101130W WO0247012A2 WO 2002047012 A2 WO2002047012 A2 WO 2002047012A2 IL 0101130 W IL0101130 W IL 0101130W WO 0247012 A2 WO0247012 A2 WO 0247012A2
Authority
WO
WIPO (PCT)
Prior art keywords
polarization
data
radiation
reading
active medium
Prior art date
Application number
PCT/IL2001/001130
Other languages
English (en)
Other versions
WO2002047012A3 (fr
Inventor
Eugene Levich
Sergei Magnitskii
Vladimir Kozenkov
Jacob Malkin
Original Assignee
Consellation Trid Inc.
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 Consellation Trid Inc. filed Critical Consellation Trid Inc.
Priority to AU2002222458A priority Critical patent/AU2002222458A1/en
Publication of WO2002047012A2 publication Critical patent/WO2002047012A2/fr
Publication of WO2002047012A3 publication Critical patent/WO2002047012A3/fr

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/005—Reproducing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
    • 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
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
    • G11B7/127—Lasers; Multiple laser arrays
    • G11B7/1275—Two or more lasers having different wavelengths
    • 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
    • G11B7/1362—Mirrors
    • 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
    • G11B7/1381—Non-lens elements for altering the properties of the beam, e.g. knife edges, slits, filters or stops
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1395—Beam splitters or combiners
    • G—PHYSICS
    • 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
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/244—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only
    • 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
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/244—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only
    • G11B7/245—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only containing a polymeric component
    • 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
    • G11B2007/0003—Recording, reproducing or erasing systems characterised by the structure or type of the carrier
    • G11B2007/0009—Recording, reproducing or erasing systems characterised by the structure or type of the carrier for carriers having data stored in three dimensions, e.g. volume storage
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/244—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only
    • G11B7/246—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only containing dyes
    • G11B2007/24624—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only containing dyes fluorescent dyes
    • 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
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
    • G11B7/244—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only
    • G11B7/246—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising organic materials only containing dyes

Definitions

  • This invention relates to methods of data recording and retrieval on WORM (write-once-read-many) or WER (write-erase-read) optical disks and cards nd the like. More particularly, it relates to two- or three-dimensional luminescent optical data carriers wherein information is recorded by means of polarized radiation and retrieved by measuring the polarization state of the luminescent, data carrying, radiation.
  • Three-dimensional, for instance, multilayer, optical storage systems provide a sufficiently high data storage capacity.
  • this imposes specific limitations on and requirements to the design and features of the optical information carrier, ways of data recording and reading, especially in the depth of the multilayer carrier.
  • every information layer of the multilayer optical information earner should possess partly reflective coating. This leads to reduction in the intensity of both recording and reading and reflected (information carrier) laser beams when they pass through the carrier to designated information layer and back to the receiver.
  • said laser beams are coherent, they can be subject to considerable diffraction and interference distortions on fragments (pits and grooves) of the information layers on their way.
  • luminescent multilayer optical information carriers with luminescent reading are preferable, as they are free of partly reflective coatings on the surface of information layers. Diffraction and interference distortion in this case will be much less due to the non-coherent nature of luminescent radiation, its longer wavelength in comparison with the reading laser wavelength, and transparency and homogeneity (similar refractive indices of different layers) of the optical data carrier in reference to the reading and luminescent radiations. Thus, luminescent multilayer data carriers have some advantages over identical reflective ones.
  • Optical storage systems based on incoherence of luminescent (fluorescent, phosphorescent) information signals have twice as high spatial resolution as compared to coherent laser ones (Wilson T., Shepard C.'Theory and Practice of Scanning Optical Microscopy", Academic Press, London, 1984). Therefore, theoretically the use of incoherent optical radiation in the multilayer optical memory can result in an eight-fold increase of the recording density and consequently of its information capacity.
  • the most optimal mode for data recording and retrieval in luminescent multilayer information carriers is cooperative two-photon absorption by non- luminescing dye precursors and/or luminescing products of photochemical reaction via an intermediate virtual level.
  • Said data reading/writing mode generally enables local information registration as luminescing marks (pits) - analogs of information pits in conventional reflective CD- or DVD-ROM - in the volume of information medium.
  • reading by luminescence ensures the highest signal-to-noise ratio in contrast to the absorption method.
  • Practical implementation of this method today is, however, hindered by the large size of femtosecond laser radiation sources requisite for said recording and the extremely low sensitivity of the photoluminescent media themselves. The latter is primarily due to the extremely low magnitudes of two-photon absorption cross-section for currently known photosensitive materials. That same reason precludes application of 1-10 mW small-size semiconductor lasers for two-photon data recording.
  • the conventional one-photon mode for recording information luminescent mark (pit) in the volume of the medium is accompanied by variations of luminescent properties throughout the recording beam's passing via the medium. This can result in occurrence of noises and degradation of contrast at reading.
  • the recording pulse energy will be low and hence the concentration of molecules capable to luminesce in the recorded pit will be also low. It can be comparable with or even lower than the total number of luminescing impurity or photoproduct molecules randomly generated while the 3-D recording medium was stored in the dark. All the above along with random exposure of the photoreceiver to extraneous radiation, could lead to occurrence of noise and degradation of contrast in reading, as in terms of intensity the luminescent reading signal will be comparable with or even much lower than the luminescent background in the same spectral band.
  • the object of the present invention is to eliminate the above-mentioned drawbacks, i.e. to improve effective sensitivity through reduced energy consumption at the stage of recording by using anisotropic photosensitive substances in the recording medium, polarized radiation at the stage of recording and registration of the state of luminescent radiation polarization at the stage of data retrieval.
  • a method for data writing and reading in two- and three-dimensional luminescent information carriers for WORM or WER optical disks and cards et al is proposed.
  • polarization-sensitive photoluminescent materials are used as media for optical data carriers in order to improve effective sensitivity of the medium in data recording, to increase the velocity of recording itself and to raise the signal-to-noise ratio in data reading.
  • Another subject of the proposed invention is the choice of photosensitive components for polarizatipn-sensitive luminescent materials from those classes of compounds that demonstrate strong absorption and/or luminescence anisotropy in the original and/or photoinduced states.
  • One more subject of the proposed invention is consecutive bit-by-bit or page-by- page recording of information by polarized radiation both in one- and two-photon absorption regimes.
  • the subject of the proposed invention is the method for data retrieval wherein the detecting signal defining the fact of presence or absence of information pit in a designated microregion of the optical recording medium is the fact of presence or absence of anisotropy of the luminescent response in a given information pit's local microregion.
  • the size of the luminescent response is virtually of no importance and is defined only by energy potentialities (photosensitivity) of the photodetective devices used for reading.
  • the subject of the proposed invention is data reading both in one- and two-photon absorption regimes.
  • the degree of polarization of the luminescent signal is determined by means of optical diagram including a modulator that rotates the polarization plane of the reading radiation and a photoreceiver that subsequently performs photoelectric separation of the variable temporary component in the luminescent signal; said component is indicative of the presence or absence of the information pit in given microregion of the recording medium.
  • luminescence anisotropy can be detected by means of two photoreceivers with subsequent comparing the intensities of two orthogonally polarized components of the luminescent signal.
  • the next subject of the proposed invention is bit-by-bit or page-by-page mode of data retrieval.
  • Fig. 1 is a schematic representation of the simplest variant of polarization data recording/retrieval on polarization-sensitive photoluminescent material.
  • Fig. 2 is a schematic representation of molecular ordering_(a) and the absorption spectrum (b) of the polarization-sensitive photoluminescent material in the original state.
  • Fig. 3 is a schematic representation of molecular ordering (a) and the absorption spectrum (b) of the polarization-sensitive photoluminescent material following polarization recording.
  • Fig. 4 is a schematic representation of molecular ordering (a) and the luminescence spectrum (b) of the polarization-sensitive photoluminescent material in data retrieval.
  • polarized information encoding has great opportunities as compared to amplitude methods.
  • information is carried by the state of polarization rather than by the phase and polarization.
  • the signal's magnitude is encoded.
  • polarization-sensitive photoluminescent materials As photosensitive components in such media, we used anisotropic compounds undergoing nonreversible or reversible (photochromic) photochemical reactions resulting in a spatially oriented molecular ensemble of photoproducts which are likewise capable of anisotropic absorption and luminescence.
  • photochromic compounds generating anisotropic luminescent photoproducts there can be used chemicals from classes of polycyclic aromatic compounds such as endopyroxides, aromatic acenes and derivatives thereof (for instance, anthracenes, naphthacenes, pentacenes, hexacenes), spiropyrane derivatives of the indoline series, acrylmethanes and diarylethylenes, stilbenes, thioindigoid dyes, compounds with intermolecular hydrogen bond, etc.
  • polycyclic aromatic compounds such as endopyroxides, aromatic acenes and derivatives thereof (for instance, anthracenes, naphthacenes, pentacenes, hexacenes), spiropyrane derivatives of the indoline series, acrylmethanes and diarylethylenes, stilbenes, thioindigoid dyes, compounds with intermolecular hydrogen bond, etc.
  • nonreversible photosensitive compounds capable of nonreversible photochemical generation of anisotropic luminescent substances
  • derivatives of furyl chromone, oxadiazole, bases of xanthene dyes, coumarin derivatives and some other compounds there can be used for instance derivatives of furyl chromone, oxadiazole, bases of xanthene dyes, coumarin derivatives and some other compounds.
  • the polarization-sensitive layers are solid polymer solutions with uniformly distributed at the molecular level photosensitive anisotropic substances capable of generating anisotropic photoproducts with polarized luminescence.
  • the polymer binder may be just as well absent.
  • the three-dimensional luminescent information carrier can represent either a multitude of polarization-sensitive layers separated by layers transparent to recording, reading and luminescent radiations or a homogeneous polymer block with uniformly distributed anisotropic photosensitive substances. Information is recorded by means of polarized radiation in both conventional one-photon absorption mode and two-quantum (cascade) or two- photon (cooperative) absorption mode.
  • writing is generally performed also by two independent sources of different wavelengths, with the light quantum energy of each of them separately leading to no changes in the medium. If the sum of two quantum energies, however, is resonant with certain frequency of two-photon absorption of the anisotropic photosensitive center, said center can switch to a virtual state with subsequent photochemical restructuring and generating anisotropically luminescing photoproduct. Information is retrieved through detecting the presence or absence of luminescence anisotropy at one- or two-photon absorption of the reading radiation.
  • data are recorded bit by bit or page by page.
  • the radiation propagation directions of two said independent sources can be either collinear or at an angle to each other.
  • their polarization vectors should be parallel, in the latter case their polarization vectors should be predominantly perpendicular to the plane defined by their propagation directions.
  • the most acceptable is a two-photon recording by one linearly polarized beam.
  • the photoinduced anisotropy in the polarization layer can be induced by both nonpolarized and polarized radiation. In doing so, the optical axis of the induced anisotropy is determined by the propagation direction of activated radiation. Data reading is also possible in both bit-by-bit and page-by-page modes using the CCD camera.
  • polarization data recording on a luminescent carrier in compliance with the present invention is sensitized polarization recording.
  • anisotropic compounds are used for anisotropic transfer of the absorbed light quantum energy onto the photosensitive anisotropic compound to yield an anisotropically luminescing photoproduct as a result of photochemical reaction.
  • the invention can be illustrated by several optical media and methods of polarization data recording/reading in one-photon, two-quantum (cascade) or two-photon (cooperative) absorption.
  • the invention can be exemplified by the one-photon principle of polarization recording and polarization reading of information on a polarization- sensitive photoluminescent carrier.
  • a polarization-sensitive photoluminescent carrier As basic components in such a carrier there can be used nonreversible photosensitive or photochromic compounds exhibiting strong absorption anisotropy in the original state and strong absorption and luminescence anisotropy the photoinduced state. It is known that the property of optical anisotropy is characteristic of the majority of substances of both natural and synthetic origin. Individual molecules are as a rule anisotropic, i.e. they possess their own absorption and radiation oscillators that in most cases can be considered linear. Probability of light absorption ⁇ by such molecules is
  • E is the vector of the light wave field intensity
  • ⁇ og is the vector of the transfer dipole moment at absorption
  • ⁇ is the angle between them.
  • Luminescence of molecules is also anisotropic to a greater or lesser extent. It is this feature that underiies the proposed method for optical information recording/writing on polarization-sensitive photoluminescent materials. Said method is as follows.
  • N A ⁇ ,y( X , y ) and N op x,y( Xl y) are volumetric concentrations of photosensitive molecules (A) and molecules of luminescent dopants, respectively, predominantly oriented along axes X,Y of the orthogonal coordinate system, said axes lying in the plane of the photosensitive material. It is assumed that polarization vector E of recording radiation Iwrite x &y) incident along axis Z is parallel to axis X. In this case, according to expression (1) only those molecules (A) are predominantly excited and enter into a photochemical reaction for which the direction of absorption oscillator ⁇ og approaches one of vector E of writing radiation Iwrite x( X ,y).
  • the concentration distribution N B ( X , y ) of luminescent molecules (B) resulting from the photochemical reaction also has a predominant orientation:
  • N ⁇ y(x,y) NA" K A y • ⁇ x(X ⁇ y ) (5)
  • coefficients K A X and K A y are functions of anisotropic properties (absorption probability (1)) and the quantum yield in the photochemical reaction of original molecules (A).
  • the whole set of molecules capable of luminescing under the action of reading radiation can be presented as composed of two parts: totally random (in terms of orientation) molecules of dopants N do p and predominantly ordered (in accord with the orientation of polarization vector of recording radiation l wite x of photoproduct molecules (B) N B (x, y ) carrying information about the recorded pits.
  • the concentration of the former is constant on the surface of the layer and is independent of the writing radiation energy, the concentration of the latter is unambiguously related to said radiation energy.
  • the photoluminescent material is exposed to reading, for instance nonpolarized, radiation l read . It is absorbed by molecules (B) and dopants; as a result their luminescence is excited.
  • the light radiated by the exposed recording medium will be partially polarized in microregions containing information marks (pits). Said light can be presented as a sum of the nonpolarized radiation of the randomly oriented ensemble of luminescent dopant molecules
  • K B X , K B y and K do p characterize luminescent capability of molecules (B) and the dopant, and l rea d is the reading radiation intensity.
  • Ifl pit x( X ,y) (K ⁇ x - N ⁇ X ( X) y) - K ⁇ y • NBy( ⁇ ,y) )-lread (1 1 )
  • the information about the recorded r ⁇ ark in the proposed method is represented as a difference of intensities of components polarized along axes X and Y independent of the intensity of the background.
  • partially polarized luminescent radiation from the exposed photoluminescent medium is transmitted for instance via a polarizer rotating at angular velocity ⁇ .
  • the light intensity behind the polarizer at each moment of time t is defined by the expression
  • the augend representing a sum of the useful weak signal and strong background, is independent of time, while the addend carrying only information about the luminescent mark (pit) recorded in the medium is modulated in time t with frequency 2 ⁇ .
  • variable component information signal
  • said variable component's magnitude can be hundred or thousand times less than the constant (background) component.
  • Fig. 1 gives a schematic illustration of a simplest embodiment of the proposed polarization method for data recording and reading on a luminescent optical card.
  • the reading principle is based on the described above rotating polarizer method.
  • the device has optical card 1 with luminescent multilayer information carrier 2, source of recording radiation 5 and source of reading radiation 8, lens elements 6, 9 and 13, photoreceiver 16, permanent polarizer 3, rotating polarizer
  • dichroic filters 10 and 12 dichroic filters 10 and 12, spectral filter 15, polarizer rotation control unit 18 and frequency selective filter 17.
  • Said device operates as follows.
  • radiation 4 of recorder 5 is polarized by polarizer 3 followed by focusing said radiation 4 by optical system 6 on one of the information layers of luminescent carrier 2.
  • the scanner (not shown in Fig. 1) reads the information bit by bit on card 1 by means of nonpolarized radiation 7 from source 8. Radiation 7 is focused in the preset microregion of one of the layers of carrier 2 by means of optical system 9 via dichroic mirrors 10 and 12. Luminescent radiation 11 from the pit being read off is directed to photoreceiver 16 by means of dichroic mirror 12 via lens system 13 and light filter 15.
  • the magnitude of anisotropy of the luminescent signal is modulated in compliance with the information written in the medium. Due to the rotation of polarizer 14, a time-fluctuated light flux is incident on photoreceiver 16. Using frequency-selective filter 17, a 2 ⁇ variable component is separated from said flux; the amplitude of said component is modulated in compliance with the information written on carrier 2.
  • Said material is isotropic in the original state but is transparent in the visible spectral range and intensively absorbs radiation with the wavelength of the order of 385 nm dying in violet with maximum absorption at 545 nm. The died form luminesces in red (about 580 nm).
  • a nitrogen laser with the wavelength of 337.1 nm was used as a source of recording polarized radiation.
  • the material specimen Prior to data recording, the material specimen had been exposed to nonpolarized radiation for 2 seconds; said procedure was equivalent to generation in the polarization-sensitive layer of molecules of luminescent dopant with spectral characteristics identical to characteristics of molecules generating luminescent information marks (pits).
  • Figs. 2-4 schematically represent the principle of sensitized two-photon polarization recording and polarization reading of information on a photochromic carrier. Figs.
  • FIG. 2a-4a schematically represent relative ordering of sensitizer molecules (1), photochromic molecules in original form A (2), as well as molecules of the dopant (3) and randomly generated molecules in form B (4) and photochromic molecules in form B carrying information (5) in the volume of the recording medium (6) in the original state (Fig. 2a), for data recording by polarized radiation with polarization vector E in the absorption band of sensitizer (1) (Fig. 3a) and for one-photon reading by polarized radiation in the absorption band of photochromic molecules in form B (Fig. 4a).
  • Figs. 2b-4b show absorption and luminescence spectra corresponding to said orderings.
  • the reason for the highly pronounced radiation anisotropy lies in that the second anisotropic excitation S ⁇ -S 2 selects excited oscillators by direction not from the chaos as the first anisotropic excitation but from certain primary anisotropy already created by the primary anisotropic excitation S 0 -S ⁇ .
  • P (l 0 - l x )/( l 0 + l ⁇ ), where ⁇ _ denotes intensity of the component polarized parallel or perpendicular to the electrical vector of recording (exciting) radiation.
  • the efficiency of said energy transfer depends not only on the extent of overlapping of the luminescence bands of dye (1) and the absorption of photochromic compound A and the distance between them, but on the relative orientation of their dipole moments.
  • the ensemble of excited photochromic molecules in form A and hence subsequently generated died photochromic molecules in form B will be anisotropic and their luminescence will be polarized (Fig. 4b).
  • the molecular ordering of the dopant remains random (Fig. 3a).
  • the absorption spectra of photochromic molecules in form A and photoproducts of form B generated under the action of polarized recording radiation will exhibit dichroism while the absorption spectrum of dopant molecules will remain isotropic (Fig. 3b).
  • the whole assemblage of molecules situated at the location of the information mark (pit) that are capable of luminescing under the action of reading radiation can be divided into two parts: totally random (isotropic in terms of orientation) molecules of dopants and predominantly ordered (in accord with the orientation of polarization vector E of the recording radiation) information carrying molecules of the photoproduct (Fig. 4b).
  • the magnitude of luminescence intensity itself, for all practical purposes, is of no importance and is restricted by the threshold sensitivity of the photoreceiver. Said photoreceiver allows registration of information pits; the intensity of said pits can be not only comparable with but lower than the intensity of the background radiation. This improves the reliability of reading.
  • Reading can be performed by means of one- or two-photon absorption.
  • the degree of polarization of the luminescent signal is determined by means of an optical diagram including a modulator that rotates the polarization plane of the reading radiation and a photoreceiver that subsequently performs photoelectric separation in the luminescent signal of the variable component with a double rotation frequency of the polarization vector of the reading radiation.
  • Said component is indicative of the presence or absence of the information pit in the specified microregion of the information medium.
  • the constant component of the background luminescence of dopant molecules is cut off enabling registration of information pits wherein the intensity of luminescence can be considerably lower than the background radiation. This allows one to reduce the power requirements of the recorder, to raise the effective photosensitivity of the actual recording medium, as well as to diminish the erasing effect of reading radiation through decreasing the intensity thereof.
  • Polarization reading permits reduction in noise and improvement of the contrast of the information pit.
  • One-photon polarization retrieval enables page-by-page reading using the CCD camera.
  • luminescence anisotropy can be detected by means of two photoreceivers with subsequent comparing the intensities of two orthogonally polarized components of the luminescent signal.
  • the further advantage of polarization data writing and reading is lower requirements to selecting and cleaning of substrates used for fabrication of the recording medium, as well as film-forming components, photosensitive and other compounds, as the proposed method allows a significant reduction in the harmful impact of luminescent molecules of dopants and external exposures.
  • One-photon information reading can be carried out by the same source of radiation as in writing provided the source's wavelength is within the absorption spectral region of the died form of a photochromic or photochemically irreversible compound.
  • the polarization luminescent method owing to its very high sensitivity can be applied up to the concentration of luminescent substances in the layer of the order of 0.001%.
  • the concentration of photosensitive molecules in known luminescent information carriers is generally 0.1-5 wt %.
  • the power requirements will be about 0.05- 1 J/cm 2 or about 5-10 "10 -10 "8 J/pit (for the pit diameter of about 1 micron).
  • the use of the proposed polarization-sensitive photoluminescent materials and polarization methods for data reading/writing can permit a reduction in concentration of anisotropic photosensitive components in each information layer of the fluorescent multilayer information carrier.
  • the result will be a lower absorption factor in individual information layers and consequently a possibility of increasing their total number in the multilayer information carrier.

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Nanotechnology (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Optical Record Carriers And Manufacture Thereof (AREA)

Abstract

La présente invention concerne un procédé permettant l'enregistrement/la récupération de données sur des supports de données optiques luminescents bidimensionnels ou tridimensionnels destiné à des disques optiques, des cartes WORM et WER et analogue. Selon ledit procédé, des matières photoluminescentes sensibles à la polarisation sont utilisées en tant que supports pour des supports de données optiques de manière à améliorer la sensibilité efficace lors de l'enregistrement de données, de manière à augmenter la rapidité d'enregistrement et à élever le rapport signal/bruit lors de la lecture de données. L'enregistrement d'informations bit-par-bit ou page-par-page est exécuté au moyen d'un rayonnement polarisé en un mode d'absorption à un ou deux photons. La lecture bit-par-bit ou page-par-page est effectuée à l'aide de la détection de la présence ou de l'absence d'anisotropie de luminescence des marques d'information (pits) en une absorption à un ou deux photons de rayonnement de lecture. Les composants photosensibles destinés aux matières luminescentes sensibles à la polarisation sont choisis parmi ces classes de composés qui possèdent une forte anisotropie d'absorption et de luminescence dans des états d'origine et/ou photo-induits.
PCT/IL2001/001130 2000-12-07 2001-12-06 Procede permettant l'enregistrement/la recuperation de donnees par polarisation sur des supports de donnees optiques luminescents WO2002047012A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2002222458A AU2002222458A1 (en) 2000-12-07 2001-12-06 Method for polarization data recording/retrieval on luminescent optical data carriers

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US25157100P 2000-12-07 2000-12-07
US60/251,571 2000-12-07

Publications (2)

Publication Number Publication Date
WO2002047012A2 true WO2002047012A2 (fr) 2002-06-13
WO2002047012A3 WO2002047012A3 (fr) 2002-10-10

Family

ID=22952524

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IL2001/001130 WO2002047012A2 (fr) 2000-12-07 2001-12-06 Procede permettant l'enregistrement/la recuperation de donnees par polarisation sur des supports de donnees optiques luminescents

Country Status (2)

Country Link
AU (1) AU2002222458A1 (fr)
WO (1) WO2002047012A2 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1912209A1 (fr) * 2006-10-10 2008-04-16 Funai Electric Co., Ltd. Support d'enregistrement optique, procédé d'enregistrement d'informations sur le support d'enregistrement optique et son procédé de reproduction
EP1973109A3 (fr) * 2007-03-02 2009-07-22 Funai Electric Co., Ltd. Procédé de reproduction d'informations à plusieurs valeurs et appareil de reproduction d'informations à plusieurs valeurs
WO2010060454A1 (fr) * 2008-11-03 2010-06-03 Institut De Ciencies Fotoniques, Fundacio Privada Dispositif permettant de déterminer une distribution d’anisotropie à polarisation de fluorescence en temps réel et procédure associée permettant de mesurer en temps réel une distribution de température dans un milieu fluide
US9275671B2 (en) 2011-06-09 2016-03-01 Case Western Reserve University Optical information storage medium

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3679309A (en) * 1970-05-04 1972-07-25 Japan Spectroacopic Co Ltd Instruments for measuring molecular orientations with the aid of fluorescence
DE2857268T1 (de) * 1977-12-19 1980-12-11 Eastman Kodak Co Medium for recording by thermal deformation
JPS61285451A (ja) * 1985-06-12 1986-12-16 Matsushita Electric Ind Co Ltd 光記録再生装置
US6090508A (en) * 1988-06-07 2000-07-18 Ricoh Company, Ltd. Optically anisotropic recording medium and method of recording and erasing information using the same
US5019476A (en) * 1988-11-16 1991-05-28 Olympus Optical Co., Ltd. Optical recording medium
JP2662024B2 (ja) * 1989-03-30 1997-10-08 松下電器産業株式会社 偏光多重記録方法
JP2940690B2 (ja) * 1989-09-22 1999-08-25 三洋電機株式会社 光記録媒体及びその再生方法
EP0436228B1 (fr) * 1989-12-28 1996-10-16 Sanyo Electric Co., Ltd. Méthodes d'enregistrement et de reproduction
JPH07111785B2 (ja) * 1990-01-19 1995-11-29 富士通株式会社 光ディスク
JP2502785B2 (ja) * 1990-03-30 1996-05-29 松下電器産業株式会社 光学記録媒体とこれを用いた記録方法及び再生方法
EP0454235A1 (fr) * 1990-04-24 1991-10-30 Koninklijke Philips Electronics N.V. Milieu d'enregistrement optique et procédé pour l'inscription, la lecture et l'effacement d'information
US5384221A (en) * 1990-12-12 1995-01-24 Physical Optics Corporation Birefringent azo dye polymer erasable optical storage medium
JP3101355B2 (ja) * 1991-08-19 2000-10-23 三洋電機株式会社 光記録媒体の記録再生方法
US5251197A (en) * 1992-02-13 1993-10-05 Hoechst Celanses Corp. Polarization dependent writing and erasing process for organic optical media
US5838653A (en) * 1995-10-04 1998-11-17 Reveo, Inc. Multiple layer optical recording media and method and system for recording and reproducing information using the same
JP3365474B2 (ja) * 1997-04-09 2003-01-14 株式会社ニコン 偏光性イメージング装置
EP1090391A4 (fr) * 1997-10-31 2001-04-11 Omd Devices Llc Disque optique photochrome multicouche de memorisation de donnees
US6280808B1 (en) * 1999-05-25 2001-08-28 Rohm And Haas Company Process and apparatus for forming plastic sheet

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1912209A1 (fr) * 2006-10-10 2008-04-16 Funai Electric Co., Ltd. Support d'enregistrement optique, procédé d'enregistrement d'informations sur le support d'enregistrement optique et son procédé de reproduction
EP1973109A3 (fr) * 2007-03-02 2009-07-22 Funai Electric Co., Ltd. Procédé de reproduction d'informations à plusieurs valeurs et appareil de reproduction d'informations à plusieurs valeurs
WO2010060454A1 (fr) * 2008-11-03 2010-06-03 Institut De Ciencies Fotoniques, Fundacio Privada Dispositif permettant de déterminer une distribution d’anisotropie à polarisation de fluorescence en temps réel et procédure associée permettant de mesurer en temps réel une distribution de température dans un milieu fluide
US9275671B2 (en) 2011-06-09 2016-03-01 Case Western Reserve University Optical information storage medium

Also Published As

Publication number Publication date
AU2002222458A1 (en) 2002-06-18
WO2002047012A3 (fr) 2002-10-10

Similar Documents

Publication Publication Date Title
US6483735B1 (en) Two-photon, three-or four-dimensional, color radiation memory
US6452890B2 (en) Optical storage medium, optical storage method, optical reading method, optical reading apparatus, optical retrieving method and optical retrieving apparatus
US8045423B2 (en) Search method
US6909684B2 (en) Optical recording medium, holographic recording and/or retrieval method and holographic recording and/or retrieval apparatus
JP2001524245A (ja) 蛍光性光メモリー
Ramanujam et al. Physics and technology of optical storage in polymer thin films
JP2001508221A (ja) ポリマーフォトクロミック組成物
JP3896092B2 (ja) 光記録媒体
JP2000082213A (ja) 光記録方法、光記録装置、光読み取り方法および光読み取り装置
US5532998A (en) Optical spectroscopic information storage
US9368145B2 (en) Reversible recording medium based on optical storage of information, method of reversible recording on such a medium
WO2002047012A2 (fr) Procede permettant l'enregistrement/la recuperation de donnees par polarisation sur des supports de donnees optiques luminescents
JP2004531849A (ja) 蛍光液晶光学メモリとその記録／読出システム
JP2008097682A (ja) 光記録媒体、光記録媒体の情報の記録方法及び再生方法
JP3780718B2 (ja) 光記録媒体、光記録再生方法及び装置
US5835245A (en) Holographic method and materials to detect and prevent forgery in identity cards
JP3994679B2 (ja) 光記録方法及び光記録装置
Yao et al. Polarization holograms recording in photochromic diarylethenes polymeric film
KR100753790B1 (ko) 광 기록매체 및 광 기록방법
JP4120838B2 (ja) 光記録方法、光読取方法、光読取装置、光記録媒体
JP2004535036A (ja) 情報の記録及び読出し手段を備えた多層複合液晶光メモリシステム
JP2001504974A (ja) 三次元の情報担体用の読取り方法およびその装置
JP4120837B2 (ja) 光記録方法、光記録装置、光読取方法、光読取装置、光検索方法、光検索装置、光記録媒体
JP2000315321A (ja) 光記録媒体上の情報の非破壊再生方法並びに光再生装置及び光記録再生装置
JP4461829B2 (ja) ホログラム記録方法及び装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PH PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
AK Designated states

Kind code of ref document: A3

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PH PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A3

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载