Thomson Licensing

Stephan Knappmann

Joachim Knittel

Gael Pilard

Hartmut Richter

Frank Przygodda

Herbert Hoelzemann

Christophe Fery

Larisa Von Riewel

Michael Krause

Stefan Kimmelmann

Juergen Moessner

Dietmar Hepper

Christian Büchler

Holger Hofmann

Christof Ballweg

Alois Kern

Sergey Khrushchev

Larisa Pacearescu

A high data density optical recording medium, a method and an apparatus for reading such an optical recording medium, and a method for mastering such an optical recording medium are proposed. For achieving a high data density the optical recording medium has marks that have a tip and are covered by a material that generates a detectable effect under the influence of high electric fields.

High data density optical recording medium

The apparatus includes a pickup for reading data from a super-resolution optical disc, the pickup comprising a laser for generating a main beam, a first and a second satellite beam, the two satellite beams each having a radial offset with regard to the main beam, a third satellite beam following the first satellite beam, having the same radial offset as the first satellite beam, and a fourth satellite beam following the second satellite beam, having the same radial offset as the second satellite beam, for providing a crosstalk correction of the HF data signal. The track pitch between adjacent tracks of the optical disc is particularly below the diffraction limit of the pickup, and the light intensity of each of the first and second satellite beams and of the main beam is sufficient to provide a super-resolution effect on the optical disc and the light intensity of each of the third and fourth satellite beams is not sufficient to provide the super-resolution effect. The track pitch between adjacent tracks of the optical disc is advantageously below the diffraction limit of the pickup.

Apparatus comprising a pickup providing multiple beams

An apparatus for reading from or writing to a near-field optical recording medium capable of detecting tilt and spherical aberration is described. The apparatus comprises a light source for generating a reading light beam, a near-field lens, an aberration compensation element, and a diffractive optical element. The diffractive optical element is switchable between a far-field mode and a near-field mode and is adapted to generate a main light beam and four or more sub-beams from the reading light beam for determining at least a cover layer thickness error signal. For this purpose it has an outer region with a first grating period and an inner region having a diameter smaller than an effective numerical aperture of the near-field lens, which in the near-field mode has a second grating period and which has a switchable inner area having a diameter smaller than a far-field numerical aperture of the near-field lens, which in the far-field mode has the first grating period. The aberration compensation element is adapted to be adjusted based on the thickness error signal when the diffractive optical element is in the near-field mode.

Apparatus for reading from and/or writing to a near-field optical recording medium

The invention relates to a method for storing data in a prerecorded area of an optical recording medium, and to an optical recording medium having at least one prerecorded area in which data is stored according to the method. It is an object to propose a method for storing data in a prerecorded area of an optical recording medium using pits and lands, whereby the signal obtained from the pits and lands is compatible with a high frequency modulated groove signal. According to the invention, the pits and lands adjacent to bit cell signal transitions are arranged in a predefined manner, either in a fixed recurring sequence of pits and lands or symmetrically to the bit cell signal transitions.

Method for storing data on an optical recording medium

The optical storage medium comprises a substrate layer, a data layer having a pit/land data structure with data arranged in tracks on the substrate layer and a nonlinear layer with a super-resolution material, wherein the data structure comprises diffractive pits and lands having a size above an optical resolution limit of a pickup for reading of the data and super-resolution pits and lands having a size below the optical resolution limit, said pits and lands having a defined length with regard to a channel bit length. A diffractive land preceding a super-resolution pit is changed by a first length depending on the laser power of the pickup, and/or a diffractive pit preceding a super-resolution land is changed by the first length depending on the laser power of the pickup, to compensate a phase shift of the super-resolution pit, respectively super-resolution land.

Optical storage medium comprising a phase shift compensation

The optical storage medium comprises a substrate layer and a data layer disposed on the substrate layer, the data layer having a mark/space data structure being arranged in tracks, wherein on a first track, the marks are enlarged in length and the spaces are shortened in length, and on an adjacent track, the marks are shortened in length and the spaces are enlarged in length. The track pitch between adjacent tracks is particularly below a diffraction limit of &#x3bb;/2*NA of a pickup for reading of the data.

Optical storage medium having different dimension of recorded marks and spaces on different tracks

A method and an apparatus for reading from a near-field optical recording medium are described. The apparatus includes:

Method and apparatus for reading from a near-field optical recording medium, and near-field lens for the apparatus

The recordable optical storage medium comprises a substrate layer, a data layer and a first and a second protection layer for the data layer, wherein the data layer comprises a semiconductor layer and a dopant layer with a doping material usable for doping the semiconductor layer. The semiconductor layer is in particular an intrinsic or essentially intrinsic semiconductor layer having a low reflectivity and the doping material of the dopant layer is selected such, that the reflectivity of the semiconductor layer is increased, when doping material of the dopant layer is diffused into the semiconductor layer.

Recordable optical storage medium comprising a semiconductor layer, and respective manufacturing method

The optical storage medium comprises tracks with a mark/space data structure, wherein the tracks comprise alternately partitioned marks and not partitioned marks. The partitioned marks are partitioned in particular in tracking direction and are partitioned in two parts, advantageously in two equal parts. The partitions are arranged advantageously such that one track comprises not partitioned marks and a neighboring track comprises partitioned marks, for reducing the track pitch of the optical storage medium and for providing an increased data capacity. The optical storage medium is in a preferred embodiment an optical disc comprising a mask layer with a suitable material for providing a super resolution near field effect, and the data structure of the optical disc comprises two spirals which have either partitioned marks or not partitioned marks. An apparatus for reading the data of a respective optical storage medium comprises a pick-up unit with a laser and a first optical element for providing a TM polarized beam and a TE polarized beam, a second optical element for separating the reflected TM and TE polarized beams, and a first and a second detector.

Optical storage medium and apparatus for reading of respective data

The optical disc comprises a substrate layer and a data layer disposed on the substrate layer, the data layer having a mark/space data structure arranged in tracks which are arranged in groups being separated each by a land section. The tracks of the groups are each arranged as a spiral, and the start of a track of a consecutive group begins at a position corresponding with the end of a track of a preceding group. A group comprises advantageously an inner track, a center track and an outer track. The optical disc comprises in a preferred embodiment a nonlinear layer with a super-resolution structure and the track pitch between neighboring tracks within a group is below the diffraction limit of a corresponding pickup for reading of data. Further, a tracking method is described which does not rely on tracking offsets to detect the inner and outer tracks of a group.

System comprising an optical disc and an apparatus for reading of respective data

An apparatus for recording angular multiplexed pits on optical recording media using a device for generating a light beam with an asymmetric intensity distribution is described. The device for generating a light beam with an asymmetric intensity distribution has at least one light influencing part for introducing a phase shift of 180&#xb0; in a first half of the light beam relative to the second half of the light beam, wherein the border between the first half of the light beam and the second half of the light beam is rotatable around an optical axis of the light beam.

Apparatus for recording angular multiplexed pits

The optical storage medium according to the invention uses a mask layer as a super resolution near field structure, which comprises a doped semiconductor material. The semiconductor material is n-doped particularly such that the reflectivity of the semiconductor material is increased, when irradiated with a laser beam. As a semiconductor material advantageously an indium alloy and as a doping material selenium or tellurium can be used. For the manufacturing of a respective optical storage medium a sputtering method for depositing the doped semiconductor material as the mask layer can be used, wherein the dopant is included already in the semiconductor sputtering target.

Optical storage medium comprising a mask layer with a super resolution near field structure

Optical pickupfor operation in the far-field and in the near-field mode comprising a movable parthaving an objective lenscomprising a solid immersion lensand a multifocal lens, which are both disposed on a common optical axis A. The multifocal lenscomprises a central zoneand a peripheral zonebeing circumferential to the central zone. The peripheral zone is adapted to constitute an optical system for a far-field mode. The central zoneof the multifocal lenstogether with the solid immersion lensare adapted to constitute an optical system for a near-field mode. The solid immersion lens and the multifocal lens are adapted to be moved in unison. A method for operating an optical pickupcomprises a first approach to a surfaceof an optical storage mediumwith the movable partto reach a far-field working distance DF based on a focus control using an optical system for working in the far-field mode, and a subsequent approach to the surfaceof the optical storage mediumwhich is performed by lowering the far-field working distance DF to a smaller near-field working distance NF.

Objective lens and optical pickup comprising the objective lens

The optical storage medium comprises a substrate layer, and a data layer having a mark/space data structure with data arranged in tracks on the substrate layer, , wherein between neighboring tracks alternatingly a groove section or a land section without a groove is arranged. The tracks, groove sections and land sections may be arranged by providing a single spiral, two spirals, or four spirals on the optical storage medium. The optical storage medium is in particular an optical disc comprising a nonlinear layer with a super-resolution structure arranged above the data layer.

Optical storage medium, mastering method and apparatus for reading of respective data

The optical storage medium comprises a substrate layer, a data layer with a mark/space structure arranged in tracks on the substrate layer, and a cover layer. One track comprises positive marks and a neighboring track comprises negative marks. The tracks are arranged in particular as spirals wherein one spiral contains a track with only positive marks and a neighboring spiral contains a track with only negative marks. The positive marks of a track and correspondingly the negative marks of a track are separated each by spaces. The optical storage medium is particularly a read-only optical disc and comprises a mask layer with a super resolution near field structure, wherein the tracks of the data layer are arranged as two spirals, one spiral consisting of positive marks only and the other spiral consisting of negative marks only. For the production of the optical storage medium, a stamper and production methods for a master for a stamper production are provided, comprising a surface with positive and negative marks, which correspond to the respective positive and negative marks of the data layer of the optical storage medium.

Optical storage medium comprising tracks with positive and negative marks, and stampers and production methods for manufacturing of the optical storage medium

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Zimmern ob Rottweil, Germany

Stephan Knappmann