Abstract: A PMR read/write head configured for thermally assisted recording (TAMR) includes thermally active bumper pads formed to each side of a write element to provide enhanced touchdown (TD) protection to the write head element where it emerges adjacent to the plasmon near-field spot produced by the TAMR apparatus. The bumper pads are disposed about the write head and absorb heat energy generated by active heating elements, the write current and the energy generated by the TAMR apparatus. Absorption of this energy causes the bumper pads to expand and protrude outward from the slider ABS to protect the read/write head from both intentional and unanticipated touchdown events. The PMR read/write head is then mounted on a slider and the assembly is incorporated into a hard disk drive (HDD).

Abstract: A communication device may supply both identification information for identifying a specific application program and first authentication information to a wireless interface so as to store both the identification information and the first authentication information in an interface memory. The wireless interface may be configured to send both the identification information and the first authentication information in the interface memory to a first terminal device by using a first communication session. The communication device may receive the first authentication information from the first terminal device by using a second communication session in a case where the second communication session with the first terminal device in which a specific application program has been installed is established via the wireless interface, and execute an authentication using the first authentication information in a case where the first authentication information is received.

Abstract: An optical storage system includes an optical head and a controller. The optical head is configured to split a light beam into a higher power main beam and a lower power side beam. The controller is configured to write data to an optical medium via the higher power main beam, and read, directly after writing, feedback from the optical medium containing the written data and noise caused by the higher power main beam. The controller is also configured to process the feedback using data indicative of the higher power main beam to remove the noise and generate output indicative of the written data, and automatically adjust a delay of the feedback or the data indicative of the higher power main beam based on a signal quality of the output.

Abstract: An optical storage system includes an optical head and controller arrangement. The arrangement is configured to write data to an optical medium via a higher power main beam, to read, directly after writing, feedback from the medium containing the written data and noise resulting from the higher power main beam, to remove the noise from the feedback by dividing the feedback with data indicative of the higher power main beam, and to generate output indicative of the written data.

Abstract: An optical storage system includes an optical head configured to split a light beam into a higher power main beam and a lower power side beam. The system also includes a controller. The controller is configured to modulate the higher power main beam according to writing commands to write to an optical medium while processing first data resulting from the lower power side beam being reflected from the medium and second data obtained from a look-up table that maps the writing commands to digital representations of filtered writing strategy waveforms to remove noise from the first data caused by the higher power main beam and generate output indicative of written data directly after writing.

Abstract: Provided are an optical pickup device and an optical disk drive including the same. The optical pickup device includes a quarter-wave plate (QWP) that is disposed parallel to an objective lens and a reflection mirror that reflects a beam back onto the QWP after the beam passed through the QWP. The optical pickup device also includes a polarization mirror that is disposed between the objective lens and the QWP, and which reflects the beam which is generated from a light source onto the QWP, and allows the beam reflected by the reflection mirror to pass through to the objective lens.

Abstract: A data recording apparatus and method using three dimensional (3D) optical memory and an authentication apparatus and method using 3D optical memory are provided. The data recording apparatus includes a recording excitation light splitting unit, a condition storage unit, and a data recording unit. The recording excitation light splitting unit splits recording excitation light into first split light and second split light. The condition storage unit stores recording conditions including information about the waveforms, wavelengths and phases of the split light and information about an arrangement of reflection mirrors configured to reflect the split light. The data recording unit records storage data by making the split light incident on the 3D optical memory through the reflection mirrors under the recording conditions.

Abstract: A holographic optical pickup device includes an optical axis split element for splitting a reference beam into two light beams in different propagation directions having polarized states substantially orthogonal to each other, angular variable elements for changing incident angle of the reference beam for irradiating an optical information recording medium, an image sensor for detecting a diffracted beam generated from a recorded region upon irradiation of the optical information recording medium with the reference beam to form a reproduction signal, and photodetectors for detecting the diffracted beam generated from the recorded region upon irradiation of the optical information recording medium with the reference beam. An angular error signal is generated for controlling the angular variable element using signals detected by the photodetectors.

Abstract: An apparatus includes a solid immersion mirror with opposing, reflective, inner sidewalls having inner surfaces facing a focal region and outer surfaces opposite the inner surfaces. The solid immersion mirror also include opposing outer sidewalls spaced apart from and facing the outer surfaces of the inner sidewalls, and a fill material between the inner sidewalls and outer sidewalls. The apparatus also includes a near-field transducer located in the focal region proximate a media-facing surface.

Abstract: The laser light source, the PBS, and the reference light mirror are arranged in such a manner as to simultaneously satisfy Lsig+LBS?s (Lld/m) (s: positive integer, m: positive integer), Lref+LBS?t (Lld/m) (t: positive integer), and u(Lld/m)?(?L/2)?Lsig?Lref?u(Lld/m)+(?L/2) (u: integer), where Lld represents an in-vacuum internal resonator length of the laser light source, LBS represents an in-vacuum-converted optical path length of a laser beam between the emission end surface of the laser light source and the PBS, Lsig represents an in-vacuum-converted optical path length of signal light between the PBS and the reflecting unit of the optical disk, Lref represents an in-vacuum-converted optical path length of reference light between the PBS and the reference light mirror, and ?L represents an interference permissible optical path length of the laser beam.

Abstract: An optical pickup device includes a laser light source 201, a collimating optical system 202 for converting laser light to parallel light, a focusing optical system 205 for focusing the parallel light onto an optical disc, a light detection unit for receiving returning light returning by reflection of the focused light from the optical disc 101 and outputting a detection signal, and a reflecting mirror 204 disposed between the collimating optical system and the focusing optical system. The reflecting mirror 204 has a reflective surface including three regions having different reflectances. The central region on the reflecting surface meets the other two regions, at positions illuminated by the light focused by the light focusing optical system, in boundary lines that are parallel to a radial direction on the optical disc 101. The reflectance of the central region is lower than the reflectances of the other two regions.

Abstract: An optical pickup device corresponding to a plurality of media is provided. The optical pickup device includes a light emitting system and a light receiving system including a plurality of light sources and a light transmission system shared by the light emitting system and the light receiving system, configured to irradiate light on a medium, and receive light reflected from the medium. The light transmission system irradiates light from the light emitting system to be appropriately focused on the medium, receives light reflected from the medium, and transports light to the light receiving system. The light transmission system includes one beam splitter corresponding to the light emitting system and the light receiving system and a position-changing collimating lens shared to correspond to a plurality of media. The position-changing collimating lens is disposed between the beam splitter and the medium, the position being controlled according to optical characteristics of the media.

Abstract: The laser light source, the PBS, and the reference light mirror are arranged in such a manner as to simultaneously satisfy Lsig+LBS?s (Lld/m) (s: positive integer, m: positive integer), Lref+LBS?t (Lld/m) (t: positive integer), and u(Lld/m)?(?L/2)?Lsig?Lref?u(Lld/m)+(?L/2) (u: integer), where Lld represents an in-vacuum internal resonator length of the laser light source, LBS represents an in-vacuum-converted optical path length of a laser beam between the emission end surface of the laser light source and the PBS, Lsig represents an in-vacuum-converted optical path length of signal light between the PBS, Lsig and the reflecting unit of the optical disk, Lref represents an in-vacuum-converted optical path length of reference light between the PBS and the reference light mirror, and ?L represents an interference permissible optical path length of the laser beam.

Abstract: An optical information reproducing apparatus and an optical information reproducing method using the same are provided. The optical information reproducing apparatus includes: a reference beam providing unit which inputs a reference beam to a reproduction recording area to be reproduced and a peripheral recording area around the reproduction recording area on an optical information recording medium, a peripheral beam detecting unit which transmits a reproduction beam reproduced from the reproduction recording area in response to the reference beam and detects a peripheral beam reproduced from the peripheral recording area, a tracking servo unit which analyzes optical information of the detected peripheral beam and controls a tracking position, and a reproduction beam detecting unit which detects the reproduction beam having pass through the peripheral beam detecting unit.

Abstract: In order to achieve further cost reduction while the package size of an optical pickup having two objective lenses and the restriction on the disposition of the two objective lenses are maintained, an optical system for laser light emitted from a red/infrared dual-wavelength laser diode is disposed such that a parallel plate beam splitter is disposed to be inclined with respect to the optical axis of focused light of the laser light reflected by an optical disk and the optical axis of the laser light between a rising mirror and the parallel plate beam splitter is inclined from the signal track direction of the optical disk. The laser light to which astigmatism is given by transmission through the parallel plate beam splitter is caused to be directly incident on a light detector without passing through an astigmatism adjustment optical element.

Abstract: An optical pickup device preventing damage or performance degradation of a second optical system. The optical pickup device includes first laser light source emitting a first light beam having a first wavelength, a first optical system guiding the first light beam emitted from the first laser light source to a first optical disc. Further, the optical pickup device includes a DVD integration unit emitting a second light beam having a second wavelength different from the first wavelength, a second optical system guiding the second light beam emitted from the DVD integration unit to a second optical disc different from the first optical disc, and a filter disposed at a position blocking incident light, of an unwanted light beam having the first wavelength and derived from the first optical system, from entering into the second optical system, so as to block the first light beam having the first wavelength.

Abstract: A pickup and a drive, in a small size, having a spherical aberration correction device capable of correcting various spherical aberration, and coma aberration and/or astigmatism with a low power consumption. A variable-focus lens actuator can correct spherical aberration such that a transparent deformation film warps into a parabolic shape when a magnetic field is applied thereto, thereby changing the light intensity distribution of transmitted light. Further, the variable-focus lens actuator can correct coma aberration and/or astigmatism by arbitrarily tilting the transparent film to change the proceeding direction of the transmitted light.

Abstract: An optical pickup apparatus comprising: a laser light source configured to emit a laser beam; an objective lens configured to apply the laser beam to an optical recording medium; and a beam splitter including a first reflective film configured to reflect the laser beam so as to be directed to the objective lens, the beam splitter interposed in an optical path between the laser light source and the objective lens, an incidence polarization angle of the laser beam relative to the first reflective film being set such that a P-polarization component is greater than an S-polarization component in linear polarization components of the laser beam incident on the first reflective film.

Abstract: In an optical pickup apparatus, a major part of an optical path of a laser beam emitted from a first semiconductor laser device and an optical path of a laser beam emitted from a second semiconductor laser device 3 are shared. The first laser beam is transmitted through a quarter wavelength plate and a second reflecting mirror and is reflected by a first reflecting mirror. With this structure, the number of parts of optical systems disposed in the optical pickup apparatus is reduced, an attachment operation of the parts becomes easier, and a time required for adjusting an optical axis is reduced. Thus, an operational efficiency is greatly improved.

Abstract: An extraction optical system for use in an optical pick-up device receiving a reflected light from an optical disc having a plurality of recording layers is provided. The extraction optical system extracts from a light in which a signal light component from an access target recording layer of the plurality of recording layers and a stray light component from a recording layer other than the access target recording layer of the plurality of recording layers are mixed, the signal light component from the access target recording layer of the plurality of recording layers. The extraction optical system includes a condensing optical element arranged in an optical path of the light and condensing the light, and a selective optical system to which the light condensed by the condensing optical element is incident and reflecting a light primarily containing the signal light component.

Abstract: For a recording and playback optical head used for a dual layer disc, it is difficult to reduce the size and the cost due to the need to correct spherical aberration caused by a difference in thickness of a light-transmitting layer. A reflection mirror having a reflection surface on which light is reflected and provided with a member having ferromagnetism at the center, and a switching device that switches between a deformed state and a non-deformed state of the reflection mirror using a magnetic force are provided. The switching device includes a hard magnetic member, and a magnetizing member that magnetizes and demagnetizes the hard magnetic member. When light is concentrated on a first recording layer farther from the light-incident surface, the reflection mirror is used as a plane mirror, and when light is concentrated on a second recording layer closer to the light-incident surface, the reflection mirror is deformed in the shape of a concave surface by means of the switching device.

Abstract: An optical pickup device capable of eliminating interlayer crosstalk which is responsible for fluctuation in control signals and error rate in data signals, thereby ensuring stable action for a multilayered recording disc with a narrow interlayer spacing. The reflected beam coming from the multilayered disc is divided along the central line into two parallel portions by the dividing optical system and then condensed. The reflected beam coming from the active layer, which has been condensed, is reflected by the reflecting plane whose reflecting region is limited and the thus reflected beam is detected by the optical detector. The reflected beam coming from other layers is not reflected by the reflecting plane, so that interlayer crosstalk is reduced.

Abstract: Disclosed is a reflecting wavelength plate that deflects and reflects a light path and adds a phase difference with respect to plural incident light having different wavelengths. The reflecting wavelength plate includes a substrate; a reflecting film laminated on the substrate; and a sub-wavelength concavo-convex structure that is laminated on the reflecting film and has a pitch less than or equal to the shortest wavelength of the plural incident light. The filling factor and the groove depth of the sub-wavelength concavo-convex structure are determined so as to add the phase difference obtained by (k?)/8, where k is an integer, to the plural incident light having the different wavelengths.

Abstract: An optical head according to the present invention includes: a first light source that emits light with a first wavelength; a beam splitter that splits the light emitted from the first light source into a first light beam traveling in a first direction and a second light beam traveling in a second direction different from the first direction; a first collimator lens for changing degrees of divergence of the first light beam; a first mirror that changes the traveling directions of the first light beam, of which the degrees of divergence have been changed; a first objective lens for converging the first light beam, which has had its traveling directions changed, toward a storage layer of a first optical disk; a mover that holds the first objective lens; a first photodetector that receives the first light beam reflected from the storage layer of the first optical disk and converts it into an electrical signal; a condenser lens for condensing the second light beam; and a second photodetector that receives the sec

Abstract: An optical head device has at least one upward-reflecting mirror, objective lenses, an objective lens actuator, and a moving mechanism. The upward-reflecting mirror receives an incident luminous flux having a wavelength emitted from a semiconductor, and changes its direction. The objective lenses having mutually different numerical apertures condense the luminous flux whose direction has been changed by the upward-reflecting mirror to radiate a condensed luminous flux onto an information recording medium. The objective lens actuator moves the objective lenses in the focus direction of the information recording medium so that the luminous flux incident on the information recording medium attains a focused state. The moving mechanism moves the upward-reflecting mirror so that the luminous flux is incident on the information recording medium via any one of the objective lenses.

Abstract: An optical pickup device has a DVD/CD laser diode for emitting a DVD/CD laser beam as linear polarized light, and a BD laser diode for emitting a BD laser beam. The optical pickup device has a dichroic mirror that regularly reflects a part of the DVD/CD laser beam, transmits a part of the DVD/CD laser beam, and transmits return light of the BD laser beam. The dichroic mirror is formed so that a product of reflectance of outward light of the DVD/CD laser beam and transmittance of return light of the DVD/CD laser beam becomes 20% or more to 25% or less. A light receiving element receives the return light of the DVD/CD laser beam transmitted through the dichroic mirror or the return light of the BD laser beam transmitted through the dichroic mirror.

Abstract: An optical pickup includes first and second objective lenses; a first raising optical element that reflects an optical beam from a first direction within a plane substantially orthogonal to an optical axis of the first objective lens, thereby the optical beam being incident on the first objective lens; and a second raising optical element that reflects an optical beam from a second direction at an angle to the first direction within a plane substantially orthogonal to the optical axis of the second objective lens, thereby the optical beam being incident on the second objective lens. At least one lateral surface of at least one of the first and second raising optical elements is at an angle of 90 degrees or smaller to a reflection surface thereof. The lateral surface of the one raising optical element is arranged to face a lateral surface of the other raising optical element.

Abstract: An optical information recording and reproducing apparatus relating to the invention employs a two-beam interference method. In the optical information recording and reproducing apparatus, a moving device moves an information recording medium between a recording and reproducing position and a retracting position, and a mirror moves together with the information recording medium. When the information recording medium moves to the recording and reproducing position, the mirror moves to a position which is displaced from the at least one of the reference beam and the information beam. When the information recording medium moves to the retracting position, the mirror moves to a position where the mirror can reflect the at least one of the reference beam and the information beam toward a detector for detecting a deviation of the at least one of the reference beam and the information beam.

Abstract: An optical head device includes a first light source and a second light source respectively emitting a first light beam and a second light beam, a luminous flux separating section selectively separating the first and second light beams for which the same optical path is used, to first and second optical paths, respectively, and a first objective lens converging the first light beam that has been separated to the first optical path on the first optical information recording medium. Further, the optical head device includes a second objective lens made of resin and converging the second light beam separated to the second optical path on the second optical information recording medium, and a first filtering section formed on a beam exit face of the second objective lens and reducing the transmittance of the first light beam to be lower than transmittance of the second light beam.

Abstract: An optical head device according to the present invention includes: a light source for outputting laser light; an optical system for allowing the laser light to be radiated onto an optical disk medium; and an aberration correction section for correcting an aberration of the laser light. The aberration correction section includes: a plurality of mirror sections for reflecting the laser light; a plurality of mirror driving sections for displacing the plurality of mirror sections; and a detection section for detecting a physical condition within the optical head device.

Abstract: An interference type optical head and an optical disk device that can easily adjust an optical path length difference of a couple of lights, ensure higher signal amplification effect, and are suitable for reduction in size are provided in order to improve a regeneration signal quality with amplification of signal in the case where reflectivity of each layer must be lowered and relative noise for the signal increases because read speed is high in a multilayer optical disk. In view of essentially improving an S/N ratio of the regeneration signal in high-speed rotation of a multilayer disk, a plurality of interference phases are generated and an optical system for differential calculation has been reduced in size with an angular selective polarization conversion element in the optical disk device for amplifying the signal with interference of the light not radiated to the disk with the reflected light from the disk.

Abstract: A holographic information recording and/or reproducing apparatus including: a light source unit emitting reference light and signal light; a first optical path guiding unit guiding the lights to cross; a second optical path guiding unit including a first polarization converter located on an optical path of one of the reference and signal lights, a first polarization beam splitter located at a crossing point of the reference light and the signal light, an optical path converter guiding the reference light and the signal light so that they cross again, a second polarization converter located on an optical path of the signal light before the signal light crosses the reference light, and a second polarization beam splitter uniting the optical paths of the reference light and the signal light; and an objective lens unit illuminating the reference light and the signal light onto one side of a holographic information storage medium.

Abstract: Apparatus and method for reading data from or writing data to a stationary optical storage medium. A light beam redirecting mechanism is rotatable about an axis through a stationary dish mirror that faces a stationary optical storage medium from which data may be read or to which data may be written.

Abstract: A multiple wavelength-adaptive optical pickup according to the present invention enables to obtain stable signals by suppressing displacement of optical intensity distribution at a light receiving section. When an incident angle of a central beam of a zero-dimensional beam of a beam reflected at an optical disc into a half mirror is taken as ?, if variation in transmittance of the mirror become a maximum with respect to change in the incident angle from ? to a plus side in any one of the wavelengths corresponding to the respective optical discs, a ?1 dimensional beam generated on the minus side with respect to the zero-dimensional beam is received by the light receiving section, and if the variation in the transmittance of the mirror become the maximum with respect to change in the incident angle from ? to the minus side, a +1 dimensional beam generated on the plus side with respect to the zero-dimensional beam is received by the light receiving section.

Abstract: An optical disc drive for recording and/or reading information on or from an optical disc is disclosed. The optical disc drive includes: a position controller which controls the position of the objective lens based on the position-controlling light beam reflected by the reflective surface by condensing the position-controlling light beam by the objective lens such that the position-controlling light beam is brought to a focus at a target guide position on the reflective surface corresponding to the target recording position; a tilt angle detector which detects tilt angle of the optical disc relative to optical axis of the position-controlling light beam; and a focal position corrector which makes a correction such that a focal position obtained when the information light beam is condensed by the objective lens is aligned to the target recording position according to the tilt angle.

Abstract: The invention provides an optical disk apparatus and an optical disk that are applicable to a multilayer optical disk, and enable tilt detection with a high precision. The optical disk has a transparent planar disk base member, a recording layer formed on the disk base member, and a reflecting layer in a certain positional relation to the recording layer. The optical disk apparatus includes a laser pointer 61 for irradiating a laser beam onto the recording layer of the optical disk by way of the disk base member to form a focusing spot on the recording layer, a photo-sensor array 6G for receiving a reflected beam from the reflecting layer, and an aberration mode detecting circuit 6H for detecting tilt of the optical disk by using an output from the photo-sensor array 6G.

Abstract: A reflecting mirror with a reflective multi-layer coating capable reflecting light beams of discrete wavelengths, e.g., laser beams in the wave ranges of CD, DVD and mass storage optical discs, free of the problem of light absorption.

Abstract: An optical disk apparatus according to the present invention includes: a light emission section for emitting laser light; an optical system for irradiating the optical disk medium with the laser light; and an aberration control section for controlling aberration of the laser light. In one embodiment, the aberration control section repeatedly switches between a plurality of aberration setting states in a focus lock-in operation. In another embodiment, the aberration control section simultaneously sets a plurality of aberration setting states in a focus lock-in operation. As a result, a plurality of aberration setting states can be allowed to substantially coexist within a single optical system.

Abstract: A deformable mirror device includes a flexible member formed so as to be deformable and having a mirror surface formed on its front surface, and a pressure generating section configured so that a direction of generation of a pressure to be applied to the flexible member is variable.

Abstract: A flux separating unit is maintained in a stable state with a high positioning accuracy relative to a physical deformation when the light flux separating unit is attached or a great temperature change after the light flux separating unit is attached, in an optical pickup device including in a casing a projection optical system, a light receiving optical system and the parallel flat plate shaped light flux separating unit that separates a light flux advancing in the light receiving optical system from a light flux advancing in the projection optical system.

Abstract: An optical pickup includes: a spherical aberration correcting portion for correcting spherical aberration by adjusting a convergence/divergence state of laser light emitted from a light source; a reflecting portion having: a first surface that chooses whether or not to pass laser light emitted from the spherical aberration correcting portion according to the wavelength of the laser light; and a second surface that reflects laser light that has passed through the first surface; and two objective lenses that are selectively used according to whether laser light reflected from the reflecting portion has been reflected by the first surface or by the second surface so as to condense light reflected from the reflecting portion onto a recording layer of an optical disc. Here, between the spherical aberration correcting portion and the objective lenses, there is disposed an astigmatism correcting portion that is formed such that the amount of correction can be changed.

Abstract: An assembly structure and method for an integrated laser/detector device with a mirror at an angle to redirect the laser beam to a medium. The mirror is not attached to the circuit board with the laser/detector as in the prior art, but rather is mounted separately in the housing immediately above the circuit board. This allows the circuit board to be moved laterally toward and away from the mirror during assembly to adjust the reflected beam along a first direction so that it contacts the photodetector. A hologram lens is mounted above the mirror, and can be rotated to adjust the reflected beam to hit the photodetector along a second, orthogonal direction. In one embodiment, two laser beams are generated, and two hologram lenses are used to separately adjust the two beams.

Abstract: An information recording/reproducing apparatus can suppress generation of stray light and prevent aggravation of the SN (signal to noise) ratio at the time of reproduction. If the angle of incidence of reference beam relative to the information recording medium (transmission-type disk 119 or reflection-type disk 213) at the time of recording is ?1, the angle of incidence of reference beam relative to the information recording medium at the time of reproduction is ?2 and the angle of incidence of reference beam reentering the information recording medium relative to the information recording medium at the time of reproduction is ?3, the angle of the galvano mirror for changing the angle of incidence of reference beam and the angle of the galvano mirror for reentering reference beam into the information recording medium are controlled so as to establish relationships of ?1??2 and ?1=?3.

Abstract: An apparatus comprises an optical waveguide, a grating for coupling light into the waveguide, and an optical element for splitting a light beam into a plurality of beams that strike the grating at different angles of incidence.

Abstract: A monitor optical device has a first region and a second region. The first region transmits part of light beam emitted from a light source to introduce the transmitted light beam to a monitor device. The second region reflects the remainder of the light beam to introduce the reflected light beam to an optical disk. The first region is formed at least within the second region.

Abstract: An optical pickup device includes a light source, a movable condensing lens, a rising prism or a rising mirror, an objective lens, and a phase plate. The light source emits laser light, and the movable condensing lens converts the laser light into converging light or diverging light. The rising prism or the rising mirror converts an optical axis of laser light passing through the condensing lens into a substantially vertical direction. The objective lens condenses the laser light, of which the optical axis is converted by the rising prism or the rising mirror, to an optical disk. The phase plate is provided between the condensing lens and the objective lens, and includes stepped portions that are formed at portions facing each other and have different thicknesses. The phase plate corrects astigmatism, which is generated by the rising prism or the rising mirror, by making a part of laser light having a size larger than a predetermined size pass through the stepped portions of the phase plate.

Abstract: An optical pickup apparatus includes a plurality of laser light sources, a single objective lens, and a beam shaping mirror. The beam shaping mirror causes each of the laser beams to be incident on a transmission surface, reflects the beam from a reflection surface being unparallel to the transmission surface and causes the beam to emerge from the transmission surface, thereby to convert a light intensity distribution of the beam of each of the wavelengths from an elliptic shape into a circular shape. The beam shaping mirror is made of a liquid crystal, which forms the transmission surface and the reflection surface, and is electrically driven so that a refractive index of the liquid crystal may be held constant irrespective of the wavelengths of the beams each of which enters the beam shaping mirror.

Abstract: Providing an objective lens with a large numerical aperture (NA), the present invention records or plays conventional optical disks such as CDs and DVDs using an optical head capable of recording or reproducing high-density optical disks. An optical element (8) is provided between a first and second laser light source and an objective lens (18) for the purpose of converting a wave front of a second optical beam 32. Furthermore, the optical element (8) and the objective lens (18) are fixed to move as a single piece.

Abstract: A method and an apparatus for recording at least two multiplexed holograms. Either an object beam or a reference beam is reflected from an aspherical reflecting surface. Either the reference beam impinging on a recording media at the selected storage location or the object beam impinging on the recording media at the selected storage location is rotated through a selected azimuthal angle about an axis that passes through a plane defined by the intersection of the object beam and the reference beam in the recording media, wherein an angle between the object beam and the reference beam impinging on the recording media is preserved.

Abstract: The present techniques provide methods and systems for enhancing a data signal in reading optical discs, such as holographic data discs. The techniques involve adjusting the position of a detector, or multi-pixel detector, such that the reflection corresponding to a micro-hologram or micro-reflector is enhanced. For example, the detector position may be adjusted to a position where the surface reflection and the micro-hologram reflection constructively interfere, resulting in an amplified micro-hologram reflection signal. Other parameters such as disc reflectivity and detector pinhole size may be adjusted to increase signal enhancement. Furthermore, the detector position may be adjusted to a position where the phases of the surface reflection and the micro-hologram reflection result in a weaker cross term.