Abstract: A structured light emitting module includes a light source and a diffractive optical component. The light source generates laser light. The diffractive optical component is arranged on an optical path of the laser light emitted by the light source for diffracting the laser light. There is no lens arranged on an optical path of the laser light emitted by the light source.

Abstract: A beam shaper for an optical inspection tool includes a focal lens to focus an optical beam onto a target at an oblique angle of incidence and a phase modulator to substantially flatten a top of the optical beam in the plane of the target when the optical beam is focused onto the target at the oblique angle of incidence.

Abstract: A scene projector includes a first cycloidal diffractive waveplate (CDW) having first pixels that are switchable such that light from a zero order passes through along an optical axis and light from plus and minus first orders is deflected away from the optical axis, and a second CDW downstream of the first CDW that includes second pixels positioned to receive diffracted orders of light from the first CDW, where there are at least three second pixels for one first pixel corresponding to each diffracted order received from the first pixel. The scene projector may further include a first reflective surface and a second reflective surface each positioned to receive diffracted orders of light from the second CDW, where each reflective surface directs light toward a grating structure. The scene projector may independently control a degree of polarization, angle of linear polarization, and intensity for light output therefrom.

Abstract: An optical pickup device according to an embodiment of the present invention includes: a light source that outputs a light beam; an irradiation optical system that projects onto a measurement target the light beam outputted from the light source; an imaging optical system that converges and images the light beam reflected by the measurement target; a light receiving part that receives the light beam imaged by the imaging optical system; and a peak separation part that when the light beams reflected by a first surface and a second surface of the measurement target are assumed to be a first reflected beam and a second reflected beam, separates peaks of light intensity of the first and second reflected beams with respect to a distance between the irradiation optical system and the measurement target in the light receiving part.

Abstract: An imaging apparatus includes a light source that emits pulsed light, a reflective encoding device, and an image sensor. The reflective encoding device includes first and second films each having light-transmitting property and light-reflecting property and a modulator disposed between the first and second films. The modulator includes modulation regions arrayed in one plane intersecting an optical path of the pulsed light and each modulating at least one of a degree of polarization, a phase, and an intensity of incident light. The image sensor receives light from a target and outputs one or more electric signals representing an image of the target on the basis of the light from the target. The reflective encoding device allows the pulsed light to undergo multiple reflection between the first and second films and allows a portion of the pulsed light to be emitted through the second film in multiple instances.

Abstract: An apparatus includes one or more error-correction decoders, a buffer, and at least one processor. The buffer may be configured to store data to be decoded by the one or more error-correction decoders. The at least one processor is generally enabled to send messages to the one or more error-correction decoders. The messages may contain datapath control information corresponding to data in the buffer to be decoded by the one or more error-correction decoders. The one or more error-correction decoders are generally enabled to decode the data read from the buffer according to the corresponding datapath control information.

Abstract: A data migration method includes retrieving data having a first data format that is associated with a first system, and generating at least one logical command that is configured to be interpreted by a migration utility. The logical command is translated to one or more equivalent physical commands that are executable by the second system, and is provided to the second system to recreate the data in accordance with a second data format that is associated with the second system. The command can be provided to the second system for execution thereby to define a system state in the second system that is equivalent to a system state of the first system with respect to the data having the first data format.

Abstract: Provided is a recording apparatus including a self-excited oscillation semiconductor laser that has a double quantum well separate confinement heterostructure and includes a saturable absorber section to which a negative bias voltage is applied and a gain section into which a gain current is injected, an optical separation unit, an objective lens, a light reception element, a pulse detection unit, a reference signal generation unit, a phase comparison unit, a recording signal generation unit, and a control unit.

Abstract: An optical head device (11) provided with: an optical element (36) for transmissively diffracting a light beam emitted from a semiconductor laser (34), generating a zero-order diffracted light beam and ±1-order diffracted light beams; and a photodetector (40) for receiving the zero-order diffracted light beam and the +1-order diffracted light beam after reflection from an optical disc (2). The photodetector (40) includes a primary light receiving section (400) for receiving the zero-order diffracted light beam, and a first secondary light receiving section (401) disposed outward from the primary light receiving section (400). The first secondary light receiving section (401) is positioned to detect an outer portion of the received light spot of the +1-order diffracted light beam, performs photoelectric conversion of this portion, and outputs a secondary detected signal.

Abstract: An objective lens (101) is configured to converge laser light of a first wavelength ?1 (390 [nm]??1?430 [nm]), laser light of a second wavelength ?2 (630 [nm]??2?680 [nm]), and laser light of a third wavelength ?3 (750 [nm]??3?810 [nm]) on an information recording surface of a first information recording medium, an information recording surface of a second information recording medium, and an information recording surface of a third information recording medium, and is configured such that the distance from a convergent point of normal diffracted order light, to a virtual collecting point formed by virtual diffracted order light between the convergent point of normal diffracted order light and a collecting point of unwanted diffracted order light is twice or more of the pull-in range of a focus error signal to be obtained in recording or reproducing information with respect to the third information recording medium.

Abstract: There is provided a playback device including a light source, an objective lens that radiates light emitted onto an optical recording medium, and onto which is incident reflected light obtained from a recording surface of the optical recording medium, a condenser lens that condenses the reflected light, a photodetecting section configured to, provided that a confocal position is a focal position of the condenser lens, ? is a wavelength of light radiated onto the optical recording medium, and NA is a numerical aperture of the objective lens, extract and detect light within a range of a diameter less than 1.5?/NA centered on an optical axis at the confocal position, and a phase difference imparting section that imparts a designated phase difference between a reflected light component from a readout track and a reflected light component from a track neighboring the readout track.

Abstract: An objective lens for an optical pickup device is characterized in that compatibility of three types of optical discs, which are a BD, a DVD, and a CD, may be realized by a common objective lens, and a flare can be created by providing an over-spherical aberration when a third optical disc is used from a size relationship between a pitch on a central region side and a pitch on an intermediate region side across a boundary and a relationship of a direction of a step in the base structures superimposed in a central region and an intermediate region of the objective lens.

Abstract: An exemplary optical pickup comprises: a light source with first and second emission points; an optical branching element which branches light emitted from the first emission point into multiple light beams including a first main beam and first sub-beams and which also branches light emitted from the second emission point into multiple light beams including a second main beam and second sub-beams; an optical system which condenses the multiple light beams produced by the optical branching element onto an optical storage medium, thereby making the first and second main beams form a write light beam spot and a read light beam spot, respectively, on a target recording track on the storage medium and making the first and second sub-beams form reference light beam spots and other light beam spots somewhere on the storage medium other than the target recording track.

Abstract: An objective lens (101) is configured to converge laser light of a first wavelength ?1 (390 [nm]??1?430 [nm]), laser light of a second wavelength ?2 (630 [nm]??2?680 [nm]), and laser light of a third wavelength ?3 (750 [nm]??3?810 [nm]) on an information recording surface of a first information recording medium, an information recording surface of a second information recording medium, and an information recording surface of a third information recording medium, and is configured such that the distance from a convergent point of normal diffracted order light, to a virtual collecting point formed by virtual diffracted order light between the convergent point of normal diffracted order light and a collecting point of unwanted diffracted order light is twice or more of the pull-in range of a focus error signal to be obtained in recording or reproducing information with respect to the third information recording medium.

Abstract: Provided are an optical pickup and an optical information storage system including the same. The optical pickup includes a photodetector that receives a main light beam and a plurality of sub-light beams reflected from an information storage medium and diffracted by a diffracting element. The photo detector detects a tracking error signal using zeroth-order light as the main light beam and using one of first-order light and third-order light as the sub-light beam based on a type of an optical information storage medium.

Abstract: Provided is an optical pickup device and a method of aligning a twin-light source in an optical disc drive. The method operates two light emitting chips in the light source simultaneously to cause two laser beams to be transmitted through a grating element at the same time. Location errors and rotation errors of the two light emitting chips with respect to the grating element may be corrected while monitoring the laser beams transmitted through the grating element.

Abstract: An optical element has at least one surface divided into a plurality of regions and includes: a first region configured to converge light with a wavelength ?1 onto a storage surface of a first optical disc and converge light with a wavelength ?2 onto a storage surface of a second optical disc; and a second region formed around the outer circumference of the first region and configured to converge light with the wavelength ?1 onto the storage surface of the first optical disc. The second region has a concave-convex structure concentrically formed on an aspheric surface and having a cross section being a saw teeth shape. The concave-convex structure is formed by a plurality of different saw teeth shapes, and the plurality of different saw teeth shapes respectively give different phase differences corresponding to substantially integer multiples of the wavelength ?1, for light with the wavelength ?1.

Abstract: An optical pickup apparatus includes at least: a light emitting element capable of emitting at least first wavelength light and second wavelength light; and a diffraction grating configured to split the first wavelength light into at least a first main beam and a first sub-beam and to split the second wavelength light into at least a second main beam and a second sub-beam, a following expression (1) being satisfied: 1.05 < Yp ? ? 1 Yp ? ? 2 < 2.50 ( 1 ) where: Yp1 is an interval between the first main beam and the first sub-beam when a first media corresponding to the first wavelength light is irradiated with the first main beam and the first sub-beam, and Yp2 is an interval between the second main beam and the second sub-beam when a second media corresponding to the second wavelength light is irradiated with the second main beam and the second sub-beam.

Abstract: An optical pickup apparatus which includes a light transmitting system is provided. A light source system provides the light transmitting system with light; a light receiving system includes detectors which are configured to detect light reflected from the multilayer optical disk; and a stray light controller is configured to prevent stray light from reaching the detectors. The stray light controller is disposed between the light source system and the light receiving system. The stray light controller includes a light transmitting portion through which light reflected from the multilayer optical disk and the stray light are configured to pass; a light diffraction portion is configured to diffract the light reflected from the multilayer optical disk and the stray light; and a light blocking portion configured to block the light reflected from the multilayer optical disk and the stray light.

Abstract: A method of designing an optical element to be used for an optical system in which each of a plurality of light beams having different design wavelengths passes through the optical element is provided. The method includes determining at least two types of optical path difference functions including first and second optical path difference functions in such a manner that proportion, brought by the first optical path difference function, between diffraction orders at which diffraction efficiencies of the plurality of light beams are maximized is different from proportion, brought by the second optical path difference function, between diffraction orders at which diffraction efficiencies of the plurality of light beams are maximized, and obtaining a shape defined by combining the at least two types of optical path difference functions so as to apply the obtained shape to at least one surface of surfaces of the optical element.

Abstract: In one embodiment of the present invention, an optical pickup for writing and reading data on an optical storage medium comprises a diffractive element for diffracting a light beam to split it into multiple light beams. The diffracted light beams includes a zero-order diffracted light beam for writing data on a track of the land or the groove of the optical storage medium and non-zero-order diffracted light beams for reading the data from the track. The diffractive element has first and second diffraction gratings that have mutually different grating vector directions and pitches. The first diffraction grating forms light beam spots on the same track by the non-zero-order and zero-order diffracted light beams. The second diffraction grating forms a light beam spot to extend to both sides of said track, or forms a light beam spot on one side of said track, by the non-zero-order diffracted light beams.

Abstract: An optical pickup and an information storage medium system using the same. The optical pickup includes a light source that emits light having a plurality of different wavelengths. The optical pickup includes a diffraction device having a plurality of diffraction patterns corresponding to the plurality of different wavelengths to divide the light incident from the light source unit into main light and sub light. The optical pickup further includes a photo-detector having a first main light reception unit that receives the main light and a first sub light reception unit that receives the sub light so as to detect an information signal and/or an error signal by receiving reflected light. The first sub light reception unit of the photo-detector is shaped so as to reduce reception of noise sub light due to diffraction based on an undesired diffraction pattern of sub light generated the diffraction device.

Abstract: In a diffractive element, its grating pattern is so configured that a diffraction angle of a diffracted light beam of a light source that is subject to the first-order diffraction in a diffraction area is matched with an angle of a light beam passing through the diffractive area emitted from a light source and a light source position is matched with a light originating point of the light source that emits a light beam to be transmitted, and the center of light intensity distribution is matched with that of the light source passing through the diffractive element by inclining an optical axis of the light source. A position of the diffractive element is adjusted based on an electric current value generated when a reflected return path light beam of the light source is diffracted by the diffractive element and enters the light source.

Abstract: Disclosed are a module to detect a tracking error signal that is easy to be assembled and robust against variation in a track angle, a diffraction grating, an optical pickup, and an optical disc apparatus that enable the module to be realized, wherein a diffraction grating divided into at least three areas, first, second, and third areas, is used; the second area is an area that do not diffract light; and focusing positions of light diffracted by the first and third areas sandwiching the second area therebetween on an optical disc are arranged with a spacing of (2n?1)×t/2 in an optical disc radial direction, respectively, where n is a nonnegative integer and t is a spacing of guide grooves of the optical disc.

Abstract: An optical pick-up apparatus for reproducing information recorded on an optical recording medium or recording information on the optical recording medium is provided. The optical pick-up apparatus includes a light source unit which generates beams; a diffraction element which diffracts the generated beams; and an objective lens which focuses a p order diffracted beam which is used for recording and reproducing information among a plurality of diffracted beams which are diffracted by the diffraction element on any one of a plurality of information layers which are formed on an optical recording medium. A p±1 order diffracted beam which is not used for recording and reproducing information is focused away from the plurality of information recording layers and on the surface of the optical recording medium.

Abstract: A compatible optical pickup including an optical unit and a focusing unit. The optical unit emits a short wavelength light for high-density recording media and a long wavelength light for low-density recording media, directs the short and long wavelength light to a recording medium, receives lights reflected by the recording medium, and detects an information reproduction signal and/or an error signal from the received lights. The focusing unit focuses light received from the optical unit to form a light spot on a recording surface of the recording medium, diffracts the short wavelength light into a zero order light and the long wavelength light into a second order light to be used as effective light for recording and/or reproduction. Thus, a high-density recording medium and a low-density recording medium having different thicknesses can be compatibly used.

Abstract: A method for driving an optical pickup apparatus which improves the durability of components that drive a movable lens that moves back and forth between an original position and a drive-limit position and achieves stable operability and an extended lifetime of the optical pickup apparatus performs a first step-drive in which a movable lens moves to an original-restoration start position by being driven a specified distance toward a drive-limit position, a second step-drive in which the movable lens thereafter moves to an original position by being driven toward the original position a distance equivalent to the distance from the drive-limit position to the original position, and a third step-drive in which the movable lens thereafter moves to a default position by being driven a specified distance.

Abstract: Provided is an optical pickup device which suppresses the decrease of light amount and performs conversion to circular polarization light, wherein the optical pickup device includes a beam splitter and a raising mirror on each of which a layered member is formed, and the optical pickup device satisfies conditional expressions relating to intensities of S-polarized light and P-polarized light with respect to the beam splitter of a laser beam emitted from a semiconductor laser element, reflectances of S-polarized light and P-polarized light on the beam splitter, a reflection phase difference obtained by subtracting a phase of S-polarized light from a phase of P-polarized light after the reflection, reflectances of S-polarized light and P-polarized light on the raising mirror, and a reflection phase difference obtained by subtracting a phase of S-polarized light from a phase of P-polarized light after the reflection.

Abstract: In one embodiment, the optical pickup device includes: a light source that emits a light beam; a diffractive element that diffracts the light beam and generates a zero-order and ±first-order diffracted light beams; an objective lens that converges the diffracted light beams onto the same track on the storage medium; and a photodetector that receives the diffracted light beams reflected from the storage medium. If a distance from a light beam spot left by the zero-order diffracted light beam on the track to light beam spots left by the ±first-order diffracted light beams on that track is d [?m], the scanning linear velocity of the storage medium is v [m/s], and a time it takes for a phase-change material of the storage medium that has once been melted by the zero-order diffracted light beam to solidify is T [?s], vT?d is satisfied.

Abstract: An objective lens element having excellent compatibility with optical discs having different base material thicknesses is provided. The objective lens element has optically functional surfaces on an incident side and an exit side. At least either one of the optically functional surfaces on the incident side and the exit side includes a diffraction portion which satisfies at least either one of the following formulas (1) and (2): ?1×?2<0 (“×” represents multiplication)??(1), (sin ?2)/?22=?(sin ?1)/?1??(2), where ?1 is the diffraction angle of a light beam having a diffraction order providing the maximum diffraction efficiency at the wavelength ?1, and ?2 is the diffraction angle of a light beam having a diffraction order providing the maximum diffraction efficiency at the wavelength ?2.

Abstract: 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.

Abstract: An optical-pickup apparatus includes: a laser diode; an objective lens; a diffraction grating; a photodetector including main-beam-, first-sub-beam-, and second-sub-beam-light-receiving portions; a quarter-wave plate having either a second area allowing a reflected-laser beam to pass therethrough without polarization or a third area allowing the reflected beam to pass therethrough at a polarization angle different from that of the first area; and a polarizing member having a separate-light-amount ratio set therefor with respect to the reflected beams passing through the second or third area and an area excluding the second or third area from the first area, such that proportions of the reflected beams passing therethrough toward the photodetector are different, thereby decreasing an irradiation level when the first- and second-sub-beam-light-receiving portions are irradiated, as stray light, with the reflected beam reflected from either one, not subjected to a signal-reading operation, of the first- and secon

Abstract: An objective optical system for an optical information recording/reproducing apparatus, at least one surface of the objective optical system being configured to be a phase shift surface having a phase shift structure, wherein: the phase shift surface has a first area contributing to converging first, second and third light beams onto recording surfaces of first, second and third optical discs, respectively; in the first area, the phase shift surface has at least two types of phase shift structures including a first phase shift structure having first steps and a second phase shift structure having second steps; the phase shift surface has a plurality of combinations of annular zones which satisfy a condition: 0.95<P1/P2<1.05??(1), and the phase shift surface satisfies a following condition: ?3.00<??1/??2<?0.10??(2).

Abstract: For use with a multi-layer optical disc, an optical pickup can eliminate a problem of causing a focus error signal and a tracking error signal to fluctuate due to interference of a signal light beam with a return light beam from another recording surface of a multi-layer optical disc during reproduction with an optical pickup that produces a tracking error signal and a focus error signal from a difference signal based on polarized reflected light.

Abstract: There is provided a diffraction grating including a convex portion and a concave portion which are used for lights having different wavelengths ?1, ?2 and ?3 and are alternately disposed on at least one surface of a substrate with a predetermined pitch. An average refractive index of the convex portion is smaller than an average refractive index of the concave portion. A phase difference in the lights having the wavelength ?1 which transmit the convex portion and the concave portion and a phase difference in the lights having the wavelength ?2 which transmit the convex portion and the concave portion are both substantially the integral multiple of 2?, and a phase difference in the lights having the wavelength ?3 which transmit the convex portion and the concave portion is substantially the non-integral multiple of 2?.

Abstract: An optical pickup apparatus comprising: an objective lens formed so that a first and second laser beams different in wavelength are respectively focused onto signal recording layers of a first and second optical discs; and a photodetector including a square-shaped light-receiving portion for being irradiated with return light, as a spot, of the first or second laser beam respectively reflected from the signal recording layers of the first or second optical discs, to generate a focus error signal, a length of a diagonal line of the light-receiving portion being substantially equal to a longer diameter of an elliptical spot formed in a direction of the diagonal line when the focus error signal is at a maximum level for an optical disc that is either one of the first and second optical discs, to which a laser beam shorter in wavelength out of the first and second laser beams is focused.

Abstract: According to the present invention, of all beams of light reflected from the optical disc, only light in a peripheral region excluding a push-pull region is used to generate a DPD signal. In this method of signal generation that optimizes internal light-receiving surface interconnections in a photodetector, the lens error signal required for the generation of a tracking error signal in the DPP scheme is amplified at a lower amplification factor. In addition, the light reflected from the multilayered optical disc will be divided into a plurality of regions and the divided beam of light will be focused at different positions on the photodetector. When the beam is focused upon a desired layer, stray light from recording layers other than those to be subjected to information reproduction will not enter the photodetector light-receiving surfaces used for servo signals.

Abstract: There is provided an optical disc drive, which includes a light source emitting a light beam, a beam dividing element that divides the light beam into main and sub-beams, an objective lens, an astigmatism producing unit that gives astigmatism to the main and sub-beams, a signal generation unit that has sensors for the beams and generates a focus error signal based on output signals of the sensors; and an optical element that has a function of adjusting intensity distribution of the main beam such that the main beam incident on the optical disc has a predetermined intensity distribution where a maximum intensity level is positioned at a predetermined height within a range of 70% of a pupil diameter, the predetermined height is not equal to an optical axis, and an intensity of the main beam decreases gradually from the predetermined height to a peripheral portion of the pupil.

Abstract: A disclosed optical pickup includes an aberration correction unit with a phase shifter surface. On the phase shifter surface, rectangular or staircase-like steps are formed in a concentric manner around an optical axial center, in certain regions where a light beam passes through. The steps have different heights in the optical axial direction. A light beam having a wavelength of 405 nm is directly transmitted through the steps so that a phase difference is applied for correcting spherical aberration that occurs on a first optical recording medium. A light beam that passes through an annular region without any steps is focused on a second optical recording medium. A light beam that passes through an outside region is focused by an object lens on the second optical recording medium, and is not focused on the first optical recording medium.

Abstract: Provided are an optical head capable of favorably recording or reproducing information to or from an information recording medium including a plurality of information recording surfaces, an optical disc device including the optical head, an information processing device including the optical disc, and an objective lens. The optical head (40) includes a blue-violet laser light source (1) which emits a blue-violet laser beam, an objective lens (8) which has an orbicular zone-shaped diffractive structure, and which diffracts the blue-violet laser beam and converges the generated diffracted light of n-th order (where n is a natural number) on a predetermined information recording surface of a multi-layer optical disc (60), and a light-receiving element (23) which receives the blue-violet laser beam reflected by the predetermined information recording surface, wherein the diffractive structure adds a positive power component and a spherical aberration component to the n-th order diffracted light.

Abstract: An objective lens, an optical head, an optical disk apparatus and an information processing apparatus which can suppress deterioration of a focal spot caused by a drop in the diffraction efficiency are provided.

Abstract: Provided is a method for forming a near-field light generating element, which is capable of sufficiently suppressing the unevenness of a waveguide surface and the distortion within the waveguide. The forming method comprises the steps of: forming a first etching stopper layer on a lower waveguide layer; forming a second etching stopper layer; forming, on the second etching stopper layer, a plasmon antenna material layer; performing etching with the second etching stopper layer used as a stopper, to form a first side surface of plasmon antenna; forming a side-surface protecting mask so as to cover the first side surface; and performing etching with the first and second etching stopper layers used as stoppers, to form the second side surface. By providing the first and second etching stopper layer, over-etching can be prevented even when each etching process takes enough etch time, which allows easy management of etching endpoints.

Abstract: An objective lens element having excellent compatibility with optical discs having different base material thicknesses is provided. The objective lens element has optically functional surfaces on an incident side and an exit side. At least either one of the optically functional surfaces on the incident side and the exit side includes a diffraction portion which satisfies at least either one of the following formulas (1) and (2): ?1×?2<0 (“×” represents multiplication) ??(1), (sin ?2)/?22=?(sin ?1)/?1 ??(2), where ?1 is the diffraction angle of a light beam having a diffraction order providing the maximum diffraction efficiency at the wavelength ?1, and ?2 is the diffraction angle of a light beam having a diffraction order providing the maximum diffraction efficiency at the wavelength ?2.

Abstract: An object of the invention is to provide an optical element for use in an optical information recording and reproducing device or a like device for recording or reproducing information with respect to an information recording medium using laser light, wherein the optical element is a resin optical element capable of suppressing lowering in transmittance due to deterioration by irradiation of light having a high energy density, and maintaining a high transmittance for a long time. To realize the above object, used is an optical element made of a silicon resin cured material obtained by subjecting a silicon resin composition containing a silsesquioxane compound to a curing treatment.

Abstract: An aberration correction element including a diffraction plane that corrects a spherical aberration caused by the difference among a first optical recording medium, a second optical recording medium, and a third recording medium by transmitting first beams of light having a wavelength of ?1 emitted from a first light source to read and write data on the first recording medium, and diffracting second beams of light having a wavelength of ?2 emitted from a second light source to read and write data on the second recording medium, and third beams of light having a wavelength of ?3 emitted from a third light source to read and write data on the third recording medium; and a phase shifter plane generating a spherical aberration ??SA having a reverse direction to a spherical aberration ?SA generated at an objective lens optimized for the first optical recording medium according to a temperature change.

Abstract: An optical disc apparatus includes a light source for emitting laser light, a light source drive unit for driving said light source, an optical element for splitting the laser light into a plurality of light fluxes, an optical element drive unit for controlling the optical element, an element for focusing the laser light onto the optical disc, and a detection unit for detecting the laser light reflected by the optical disc. Reproduction of the optical disc is performed by switching effectiveness and ineffectiveness of a function of splitting the light flux of the optical element, and adjustment of an outgoing laser power is performed.

Abstract: An optical device having a sub-wavelength grating formed in a specified region is disclosed that is able to prevent wave front degradation accompanying a phase difference of a polarized light beam passing through the optical device. The optical device includes a circular-belt-like region where the sub-wavelength diffraction grating is formed, and a center portion where the sub-wavelength diffraction grating is not formed. A vertically polarized light beam used for operations on a blue-light optical recording medium A has a phase difference in the sub-wavelength diffraction grating to be an integral multiple of 2? and hence is transmitted through the sub-wavelength diffraction grating. A horizontally polarized light beam used for operations on a blue-light optical recording medium is diffracted by the sub-wavelength diffraction grating.

Abstract: An optical pickup and an information storage medium system using the same. The optical pickup includes a light source that emits light having a plurality of different wavelengths. The optical pickup includes a diffraction device having a plurality of diffraction patterns corresponding to the plurality of different wavelengths to divide the light incident from the light source unit into main light and sub light. The optical pickup further includes a photo-detector having a first main light reception unit that receives the main light and a first sub light reception unit that receives the sub light so as to detect an information signal and/or an error signal by receiving reflected light. The first sub light reception unit of the photo-detector is shaped so as to reduce reception of noise sub light due to diffraction based on an undesired diffraction pattern of sub light generated the diffraction device.

Abstract: A multilayer optical recording system to record information with light includes a lens unit, a recording medium, and a microscopic drive unit. The lens unit includes a metamaterial lens or a plasmon lens. The metamaterial lens has a first dielectric member in which first microstructures are implanted in a substantially regular manner. The plasmon lens has an aperture. The aperture is a hole or a slit created in a metal film. The microscopic drive unit is configured to adjust a relative position between the lens unit and the recording medium. In addition, the principal plane is placed to be in contact with the lens unit or to have a gap between the principal plane and the lens unit. Furthermore, the second microstructures are arranged periodically in a direction substantially perpendicular to the principal plane of the recording medium.

Abstract: An optical information recording method of recording information three-dimensionally by irradiating a laser light beam onto a medium having a servo information plane on which address information and/or servo information is recorded, is disclosed. The method includes the steps of: dividing a laser light beam from one laser light source into laser light beams, the beam including a first light beam for reading the information, and a second light beam for recording information onto the recording medium; irradiating the first light beam onto the servo information plane to read the information from reflected light of the first light beam to read the information in which optical axes of the first light beam and second light beam are arranged coaxially; and irradiating the second light beam based on the read information to be focused onto a position in a depth direction perpendicular to a horizontal direction of the recording medium.