Abstract: A low loss high extinction ratio on-chip polarizer is disclosed. The polarizer includes an input waveguide taper having an outer waveguiding region that widens in the direction of light propagation along at least a portion of the taper length, and a core waveguiding region that narrows in the direction of light propagation along at least a portion of the taper length, so as to selectively squeeze out light of undesired modes into the outer regions while preserving light of a desired mode in the waveguide core. An output filter section is provided to prevent light from reentering the output waveguide after being squeezed out. An integrated light absorber/deflector may be coupled to the outer waveguiding regions.

Abstract: An optical transmission assembly for transmitting a source image includes a waveguide assembly, an incoupling assembly for coupling light emitted from the source image into the waveguide assembly, and an outcoupling assembly for coupling the light guided in the waveguide assembly out of the waveguide assembly. The light emitted from the source image and coupled into the waveguide assembly can be propagated between the incoupling assembly and the outcoupling assembly in the waveguide assembly by means of a total reflection. The incoupling assembly has at least one diffractive incoupling grating which is inclined by an angle (?) ranging from 20° to 60° relative to a normal of a boundary surface of the waveguide assembly, and/or the outcoupling assembly has at least one diffractive outcoupling grating which is inclined by an angle (?) ranging from 20° to 60° relative to a normal of a boundary surface of the waveguide assembly.

Abstract: An apparatus includes a substrate. A laser is formed on a non-self supporting structure and bonded to the substrate. A waveguide having a gap portion is deposited proximate the laser. The waveguide is configured to communicate light from the laser to a near-field transducer (NFT) that directs energy resulting from plasmonic excitation to a recording medium. An optical isolator is disposed over the gap portion.

Abstract: An optical modulator includes an optical waveguide of a ridge type formed of a thin film of a dielectric material having an electro-optic effect over a substrate, a buffer layer covering the optical waveguide, and a signal electrode provided over the optical waveguide via the buffer layer, wherein a width of the signal electrode is greater than a ridge width of the optical waveguide and wherein the signal electrode covers at least one of sidewalls of a ridge of the optical waveguide.

Abstract: A low loss high extinction ratio on-chip polarizer. The polarizer includes an input waveguide taper having an outer waveguiding region that widens in the direction of light propagation along at least a portion of the taper length, and a core waveguiding region that narrows in the direction of light propagation along at least a portion of the taper length, so as to selectively squeeze out light of undesired modes into the outer regions while preserving light of a desired mode in the waveguide core. An output filter section is provided to prevent light from reentering the output waveguide after being squeezed out. An integrated light absorber/deflector may be coupled to the outer waveguiding regions.

Abstract: A virtual reality display apparatus including at least a display and at least an optical assembly is provided. The display provides an image beam to a user's left eye or right eye. The optical assembly disposed on the transmission path of the image beam includes at least a Fresnel lens. Each of the display and the optical assembly both has a tilt angle relative to an upward direction, wherein the upward direction is the direction perpendicular to the user's horizontal sight line plane and defined as the direction pointing from the user's neck to the top of the user's head, and the tilt angle is within a range greater than 0 degree and is smaller than or equal to 20 degrees.

Abstract: A method of optical communication in a well can include launching light having substantially coherent phase into an optical waveguide extending in a wellbore, modulating light having substantially coherent phase in the wellbore, and receiving the modulated light transmitted via the same optical waveguide. A well system can include at least one optical waveguide extending in a wellbore, and a downhole optical modulator which modulates light transmitted via the optical waveguide, the optical modulator comprising a potassium titanyl phosphate crystal. Another method of optical communication in a well can include launching light into an optical waveguide extending in a wellbore, the light launched into the optical waveguide having information modulated thereon using a carrier, modulating light in the wellbore, the modulating comprising modulating information using a subcarrier of the carrier, and transmitting the light modulated in the wellbore via the same optical waveguide.

Abstract: A low loss high extinction ratio on-chip polarizer is disclosed. The polarizer includes an input waveguide taper having an outer waveguiding region that widens in the direction of light propagation along at least a portion of the taper length, and a core waveguiding region that narrows in the direction of light propagation along at least a portion of the taper length, so as to selectively squeeze out light of undesired modes into the outer regions while preserving light of a desired mode in the waveguide core. An integrated light absorber/deflector may be coupled to the outer waveguiding regions.

Abstract: A grating structure for a grating coupler is provided which has a high efficiency resulting from the operating principle, is easily manufactured, and simultaneously has little reflection loss. This grating structure is provided with a core layer having periodic recesses and protrusions formed on the upper surface, a first upper cladding layer in contact with the upper surface of the core layer, a second upper cladding layer in contact with the upper surface of the first upper cladding layer, and a first lower cladding layer in contact with the lower surface of the core layer. The recessed portions of said recesses and protrusions are filled with the same material as the first upper cladding layer. The refractive index of the material forming the core layer is greater than the refractive index of the materials forming the first upper cladding layer, the second upper cladding layer and the first lower cladding layer.

Abstract: An electrical device that in one embodiment includes a first semiconductor device positioned on a first portion of a type IV semiconductor substrate, and an optoelectronic light emission device of type III-V semiconductor materials that is in electrical communication with the first semiconductor device. The optoelectronic light emission device is positioned adjacent to the first semiconductor device on the first portion of the type IV semiconductor substrate. A dielectric waveguide is present on a second portion of the type IV semiconductor substrate. An optoelectronic light detection device of type III-V semiconductor material is present on a third portion of the type IV semiconductor device. The dielectric waveguide is positioned between and aligned with the optoelectronic light detection device and optoelectronic light emission device to transmit a light signal from the optoelectronic light emission device to the optoelectronic light detection device.

Abstract: A write head includes a near-field transducer near a media-facing surface of the write head. The write head includes a waveguide having a core with a first side disposed proximate to the near-field transducer. The core overlaps the near-field transducer at a substrate-parallel plane. The core includes one of a step or a taper on a second side facing away from the first side. The step or the taper causes a reduced thickness of the core normal to the substrate-parallel plane. The write head includes a cladding layer that encompassing the second side of the core and that fills in the step or the taper.

Abstract: A write head includes a near-field transducer near a media-facing surface of the write head and a waveguide. The waveguide includes a core that overlaps or is co-planer with the near-field transducer at a first region. The core has a second region extending away from the near-field transducer to an energy source. The core has a third region between the first and second regions. The third region has a third crosstrack width that is less than first and second crosstrack widths of the first and second regions.

Abstract: An apparatus includes a waveguide with first and second sections, and a junction coupling the first and second waveguide sections together. The first waveguide section has a first reflective device and the second section comprising a second reflective device arranged to generate a standing wave in the waveguide with maximum energy wave intensity at a target region of the waveguide in response to an incident energy wave being provided into at least one of the waveguide sections.

Abstract: An optical coupling system is provided which includes a first layer structure and a second layer structure. The first layer structure includes a plurality of layers sequentially stacked on a substrate, and is configured to compresses a beam emitted from a light source along a direction substantially perpendicular to a top surface of the substrate. The second layer structure is formed on the substrate, and is configured to compresses the beam, having passed through the first layer structure, along a direction substantially parallel to the top surface of the substrate.

Abstract: An apparatus has an input surface configured to receive energy emitted from an energy source in a first mode. A mode order converter is configured to convert the energy from the first mode to a second mode. The waveguide of the apparatus has an input end disposed proximate the input surface and configured to receive the energy in the first mode. The waveguide has an output end disposed proximate a media-facing surface and configured to deliver energy in the second mode. The output end is at an oblique angle to a cross-track line at an intersection of the media-facing surface and a substrate-parallel plane.

Abstract: An optical waveguide lens includes a substrate, and a planar waveguide and a media grating formed on the substrate in sequence. The media grating includes a first group of gratings located adjacent to the light source and a second group of gratings away from the light source. The first group of gratings and the second group of gratings each include a plurality of strip-shaped films arranged in parallel. The first group of gratings and the planar waveguide under the first group of gratings cooperatively define a first waveguide section. The second group of gratings and the planar waveguide under the second group of gratings cooperatively define a second waveguide section. Light radiated from a light source passes through the optical waveguide lens and is successively converged by the first waveguide section and the second waveguide section. An optical coupling module incorporating the optical waveguide lens is also provided.

Abstract: The present invention provides a printed coil substrate for an optical disc actuator so that the sensitivity will change as little as possible when shifting in a focal direction and a tracking direction. Although the coil patterns laminated at a corresponding position have approximately same shape, center locations in shape of the tracking coil and the focus coils are displaced between the neighboring substrate layers, and the center locations in shape are displaced by a predetermined distance toward a direction of driving the movable portion driven by the coils. Even when the coil pattern of the first layer is moved in a direction of leaving from the position where magnetic force of the magnet is strong, the coil pattern of the second layer is simultaneously moved into the position where magnetic force of the magnet is strong. Therefore, the change of the sensitivity can be relatively compensated.

Abstract: A device including a near field transducer (NFT); a write pole; at least one dielectric material positioned between the NFT and the write pole; and an adhesion layer positioned between the NFT and the at least one dielectric material.

Abstract: An optical scanner includes a substrate, and a tunable laser on the substrate, wherein the tunable laser is configured to emit light, and to sweep a wavelength of the emitted light through a waveband. The optical scanner further includes a grating over a top surface of the substrate, the grating configured to diffract light emitted from the tunable laser, and an angled reflective surface configured to reflect the diffracted light from the grating. The optical scanner further includes a refractive element configured to receive the reflected light from the angled reflective surface. The refractive element is configured to focus the reflected light in a first direction and to diverge the reflected light in a second direction perpendicular to the first direction.

Abstract: An electronic component having a laminate formed by laminating a plurality of insulator layers and a helical coil provided in the laminate, the coil including first and second coil conductors, and via-hole conductors provided so as to pierce through the insulator layers. The first and second coil conductors are opposed to each other via the insulator layers in a direction of lamination. The first coil conductor has a first side opposed to the second coil conductor and having a convex portion in a cross section normal to a direction in which the first coil conductor extends. The second coil conductor has a second side opposed to the first coil conductor and has a concave portion in a cross section normal to a direction in which the second coil conductor extends. The concave portion overlaps the convex portion in the direction of lamination.

Abstract: A waveguide lens includes a substrate, a planar waveguide, a media grating, a pair of first electrodes, and a pair of second electrodes. The planar waveguide is formed on the substrate and is coupled with a laser light source, which emits a laser beam having a divergent angle into the planar waveguide. The media grating is formed on the planar waveguide. The pair of first electrodes is configured to change an effective refractive index of the planar waveguide, utilizing an electro-optical effect, when a first modulating electric field is applied, where the effective refractive index is corresponding to a transverse electric wave. The pair of second electrodes is configured to change an effective refractive index of the planar waveguide, utilizing an electro-optical effect, when a second modulating electric field is applied, where the effective refractive index is corresponding to a transverse magnetic wave.

Abstract: A photonic integrated circuit (I/C) includes a focusing sidewall or in-plane surface that redirects and focuses light from a waveguide to a photodetector structure. The focusing includes redirecting an optical signal to a width smaller than a width of the waveguide. The focusing of the light allows the photodetector structure to be outside a waveguide defined by parallel oxide structures. With the photodetector structure outside the waveguide, the contacts can be placed closer together, which reduces contact resistance.

Abstract: A laser beam applying mechanism has a power adjusting unit provided between a laser beam oscillator and a focusing lens. The power adjusting unit includes a half-wave plate, a prism having a first polarization beam splitter film and a second polarization beam splitter film. The optical path is adjusted by a piezoelectric actuator opposed to the first polarization beam splitter film, and a polarized light components synthesizer opposed to the second polarization beam splitter film generates a phase difference (?) between an S polarized light component and a P polarized light component. The phase difference (?) between the S polarized light component and the P polarized light component of the laser beam obtained by the polarized light components synthesizer is in the range of 0° to 180°.

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 device includes a laser diode for emitting a laser beam, an objective lens for collecting the light beam emitted from the laser diode and irradiating an optical disc with the collected light beam, a diffraction element for making the light beam reflected from the optical disc diverge, and a detector having a plurality of detection parts for receiving the diverging light beams caused by the diffraction element. The diffraction element has first, second, and third divided areas, wherein a 0th-order diffracted light from the first divided area, the second divided area, and the third divided area is detected by at least four divided detection parts; and at least two detection parts for detecting the light beam diffracted at the first divided area into first or higher diffraction order are aligned in a direction generally perpendicular to the track of the optical disc.

Abstract: A semiconductor light emitting device downsized by devising arrangement of connection pads is provided. A second light emitting device is layered on a first light emitting device. The second light emitting device has a stripe-shaped semiconductor layer formed on a second substrate on the side facing to a first substrate, a stripe-shaped p-side electrode supplying a current to the semiconductor layer, stripe-shaped opposed electrodes that are respectively arranged oppositely to respective p-side electrodes of the first light emitting device and electrically connected to the p-side electrodes of the first light emitting device, connection pads respectively and electrically connected to the respective opposed electrodes, and a connection pad electrically connected to the p-side electrode. The connection pads are arranged in parallel with the opposed electrodes.

Abstract: Provided are an optical head and an optical information device capable of inhibiting the temperature rise of a photodetector. An optical head (10) includes a semiconductor laser (101) which emits a luminous flux, an objective lens (105) which focuses the luminous flux emitted from the semiconductor laser (101) on the optical disk (21), and a photodetector (120) which detects the luminous flux reflected by the optical disk (21). The photodetector (120) includes a light receiving part (123) which receives the luminous flux reflected by the optical disk (21), a package (125) which covers the light receiving part (123), and a heat transfer adhesion layer (124) disposed between the package (125) and the light receiving part (123). The heat transfer adhesion layer (124) is formed in a region that is on the light receiving part (123) and includes a light path through which the luminous flux reflected by the optical disk (21) passes.

Abstract: An optical pickup head is provided, which includes a silicon substrate, in which an aperture and an objective lens are disposed on the silicon substrate; and a laser diode (LD), a 135-degree tilted reflector, and a 135-degree tilted holographic reflector are disposed on the silicon substrate. The two 135-degree tilted reflectors and a holographic optical element (HOE) are fabricated on a slant face structure of an optical platform using a semiconductor process, so all the elements are disposed at a straight zone, and then in combination with bonding of the LD and an optical sensor element, an miniaturization objective is achieved and an optical path is shortened.

Abstract: A phase difference layer 12 and a reflection layer 13 are provided. Then, adjustment is performed such that the phase difference layer 12 and the reflection layer 13 impart a predetermined phase difference to light having a particular wavelength bandwidth or plural kinds of light of different wavelengths that enter in an oblique direction relative to the normal direction of the plane of the phase difference layer 12. By virtue of this, the light 16a that goes forward and backward through the phase difference layer 12 and then exits the layer has an ellipticity ? of 0.7 or greater. Thus, in particular, when this wave plate is employed in an optical head device, the function of reflection and the function of a ¼-wave plate are integrated. Thus, stable recording and reproduction of an optical disk are achieved, and size reduction is achieved in the optical head device.

Abstract: A processing circuit for optical data is provided. The processing circuit includes a signal-processing module and a radio frequency (RF) signal-summing module. The signal-processing module averages and filters the data signals to obtain a low-frequency signal. The RF signal-summing module receives the data signals and the low-frequency signal, sums the data signals to obtain a summed data signal, and subtracts the low-frequency signal from the summed data signal to obtain a RF summing signal.

Abstract: An optical waveguide of the invention includes a core that is a waveguide through which light propagates; and a cladding that surrounds the core. The core has a plate shape and includes a wide core base part onto which the light is incident, a taper part that is connected to the core base part and of which a width is gradually tapered along a propagation direction, and a narrow front end core part that is connected to the taper part and that extends along the propagation direction.

Abstract: A semiconductor light emitting device downsized by devising arrangement of connection pads is provided. A second light emitting device is layered on a first light emitting device. The second light emitting device has a stripe-shaped semiconductor layer formed on a second substrate on the side facing to a first substrate, a stripe-shaped p-side electrode supplying a current to the semiconductor layer, stripe-shaped opposed electrodes that are respectively arranged oppositely to respective p-side electrodes of the first light emitting device and electrically connected to the p-side electrodes of the first light emitting device, connection pads respectively and electrically connected to the respective opposed electrodes, and a connection pad electrically connected to the p-side electrode. The connection pads are arranged in parallel with the opposed electrodes.

Abstract: In a particular embodiment, a recording head includes a tapered waveguide adapted to propagate light from a light source a slider adjacent to a surface of a storage medium. The tapered waveguide is adapted to output an elliptical beam to a grating coupler on a slider. The recording head further includes a slider waveguide extending substantially normal to a surface of the storage medium and a grating adapted to couple the elliptical beam into the slider waveguide.

Abstract: There is provided an optical member 1 in which a fixation member 3 supporting the light emitting member 2 is fixed to a housing 5 supporting a light receiving member 4, so as to have clearances between the fixation member 3 and the housing 5, by photocurable resin 6 bridging the clearances, recesses 7 that adjoin positions where the photocurable resin 6 is deposited, that are opened so as to allow casting of light into the recesses 7, and that are to receive portions of the photocurable resin 6 are formed on the housing 5.

Abstract: An apparatus includes a waveguide having a core layer and first and second cladding layers on opposite sides of the core layer, wherein the cladding layers comprise a binary oxide composition. In another example, the cladding layers include a ternary or quaternary combination of oxides and/or oxynitrides. In another example, the cladding layers include a silicon oxynitride.

Abstract: A laser attachment device of the present invention is formed of a LD package and a LD holder housing it. A first inner wall of the LD holder to come into contact with a side surface of the LD package is an inclined surface. This allows the facing direction of the LD package to be corrected by the first inner wall being the inclined surface, even when a laser beam emitted from a light emitting chip housed in the LD holder is inclined with respect to an optical axis. Thus, the traveling direction of the laser beam is corrected to the optical axis side.

Abstract: An optical integrated unit according to the present invention is an optical integrated unit, including: a semiconductor laser acting as a light source; at least one light-receiving element; a light-separating section for separating light emitted by the semiconductor laser from light reflected by an optical disc and for reflecting the light reflected by the optical disc so that the light reflected by the optical disc is directed to the light-receiving element; and a support substrate, wherein a second support substrate has a concave shape, the light-separating section is constituted of at least three prisms, the prisms positioned at both ends of the light-separating section are respectively attached to two protruding sections of the concave shape of the second support substrate, and the light-receiving element is attached to the light-separating section via a cover glass.

Abstract: An optical device includes a sub-mount 2 mounting first and second semiconductor lasers 1a, 1b and having an onboard part for the semiconductor lasers and an optical-path conversion mirror 7 integrated with each other, and a light receiving element 11 arranged on a light receiving element substrate to have first and second light receiving regions separated from each other by at least one parting line. In the optical device, one light gravity center of an optical spot, which is formed on the light receiving element 11 by homeward flux of light emitted from the first semiconductor laser 1a and reflected by an optical disc 55, and another light gravity center of an optical spot, which is formed on the light receiving element 11 by homeward flux of light emitted from the second semiconductor laser 1b and reflected by the optical disc 55 are together positioned on the parting line.

Abstract: An optical pickup apparatus comprising at least: a diffraction grating configured to split first wavelength light into at least a first main beam and first sub-beam, and to split second wavelength light into at least a second main beam and second sub-beam, the diffraction grating including a diffraction surface portion corresponding to the second wavelength light; and a photodetector including a first main light-receiving unit configured to be applied with the first main beam, a first sub-light-receiving unit configured to be applied with the first sub-beam, a second main light-receiving unit configured to be applied with the second main beam, and a second sub-light-receiving unit configured to be applied with the second sub-beam, a distance between the first main light-receiving unit and first sub-light-receiving unit being changed relative to a standardized distance between the first main light-receiving unit and first sub-light-receiving unit.

Abstract: An integrated circuit for optical disc comprising for each of light-receiving surfaces: an operational amplifier including inverting and noninverting input terminals receiving first and second input voltages, and output terminal receiving output voltage; a feedback resistor connected between the inverting input and output terminals; a photodiode connected between one power supply line of the first and second power supply lines and the inverting input terminal to generate current corresponding to reflected light; a capacitor connected between the one power supply line and the noninverting input terminal; and an input resistor connected between reference power source and the noninverting input terminal, further comprising: an adder adding voltages corresponding to the output voltages to generate RF signal, capacitance of the capacitor and resistance value of the input resistor being determined in accordance with capacitance of parasitic capacitor connected in parallel with the photodiode and resistance value of

Abstract: An optical pickup device includes a hosing having three walls connected together whose horizontal cross-section is substantially U-shaped. A first wall supports one end of a shaft, a second wall facing the first wall supports the other end of the shaft and a third wall connects the first and second walls. A lubricant tray is surrounded by the three walls and the shaft. By the shaft being attached to an end side surface of the lubricant tray, the shaft can be integrally formed with the housing. A radius of curvature or an angle formed on a horizontal cross-section of the three walls is larger than a radius of curvature or an angle formed between one of the three walls and the lubricant tray.

Abstract: An optical integrated device includes a light source; a light splitting-and-guiding section that splits a reflected light beam into two end light beams, a connection light beam, and a residual light beam, and guides the two end light beams and the connection light beam in directions different from a direction of the residual light beam; and a light receiving section that receives the two end light beams and the connection light beam with photodetection devices divided, in the tangential direction, into at least two regions within a range in which the connection light beam is incident, receives the residual light beam with photodetection devices divided, in the tangential direction, into regions having widths corresponding to portions on which the two end light beams are incident, and outputs a detection signal in accordance with an amount of light received with each of the photodetection devices.

Abstract: A near field optical disc and a near field optical disc reading apparatus are provided. The near field optical disc has at least one light source and a near field optical pick-up head, and the near field optical disc includes a light guiding substance, a first reflection layer and a second reflection layer. The light guiding substance has a first surface, a second surface opposite thereto and at least one light entrance window. Light emitted from the light source enters the light guiding substance through the light entrance window. The second reflection layer is disposed on the second surface. The first reflection layer is disposed on the first surface and has a plurality of light pervious holes. A part of the light is transmitted through the light pervious holes and picked up by the near field optical pick-up head.

Abstract: Disclosed herein is a technology that enables stable and high-speed writing and/or reading in an optical disk apparatus. The optical disk apparatus has an optical head that includes a first circuit for driving a laser diode, a second circuit for sampling and holding analog electric signals that are based on reflected laser light from the optical disk, and a third circuit for converting said signals being sampled and held into digital signals. Signals digitized in the optical head are transmitted to the apparatus body side using time-division multiplexing. The first circuit, the second circuit, and the third circuit are constructed on a single substrate or in a single IC.

Abstract: A diffraction optical element is provided to reduce harmful lights and also suppress deterioration in the optical characteristics of the element. The diffraction optical element 22 is formed with a plurality of diffraction gratings 17?, 18?, 19? and 20?. From these diffraction gratings, there are selected the diffraction gratings 18?, 19? and 20? whose groove apex angles are less than a predetermined angle. The diffraction gratings 18?, 19? and 20? has chamfer surfaces 18c?, 19c? and 20c? formed on the lower side of respective slanted surfaces 18a?, 19a? and 20a?. The chamfer surfaces 18c?, 19c? and 20c? are slanted to the slanted surfaces 18a?, 19a? and 20a?, respectively.

Abstract: An objective lens formed of a synthetic resin material having characteristics of substantially not reducing transmittance of the objective lens when a first laser beam having a first wavelength passes through the objective lens, and reducing the transmittance according to an elapsed time to apply a second laser beam when the second laser beam having a second wavelength shorter than the first wavelength and longer than a wavelength of ultraviolet light passes through the objective lens, the objective lens being irradiated with the ultraviolet light in advance for a predetermined time such that a change in the transmittance for the second laser beam is set within a predetermined range.

Abstract: The invention relates to a compact optical pickup for a micro optical drive, and to a micro optical drive using this compact optical pickup. According to the invention a pickup for optical recording media includes a light source for generating a light beam for reading from and/or writing to an optical recording medium, a flexible arm serving as a focus actuator, an objective lens situated on the flexible arm for focusing the light beam onto the optical recording medium, an optical bench for directing the light beam towards the optical recording medium one or more detectors for detecting the light beam reflected by the optical recording medium, and a mirror, which is arranged inclined with respect to a transparent block of the optical bench, for directing the light beam reflected by the optical recording medium towards a first detector.

Abstract: A compatible optical pickup can be used with advanced optical discs (AODs), blu-ray discs (BDs), digital versatile discs (DVDs), and compact discs (CDs). The compatible optical pickup comprises a first light source unit for independently projecting first and second short-wavelength laser beams which have different polarizations, a second light source unit for independently projecting first and second long-wavelength laser beams which have different wavelength-range, a first objective lens that has a high numerical aperture suitable for a high density optical information recording medium, a second objective lens that has a low numerical aperture suitable for a low density optical information recording medium, and a light path changing unit for guiding the first short-wavelength laser beams to the first objective lens and guiding the second short-wavelength laser beams, the first long-wavelength laser beams, and the second long-wavelength laser beams to the second objective lens.

Abstract: An optical disc apparatus for recording, reproducing or erasing an information signal by converging a light flux onto a recording layer through a transparent substrate. The apparatus includes one or a plurality of optical heads having a plurality of objective lenses whose aberrations have respectively been corrected for a plurality of disc substrates of different thicknesses, a cartridge for enclosing the optical disc, a discrimination hole which is formed on the cartridge, and a sensor for detecting the opening/closing state of the discrimination hole and for generating a discrimination signal. In accordance with the result of the discrimination as to the thickness of the loaded optical disc, the objective lens, in which the occurrence of the aberration is smallest, is used, so that the information signal can preferably be recorded, reproduced or erased onto/from the optical discs having different substrate thicknesses.

Abstract: An optical disc apparatus for recording, reproducing or erasing an information signal by converging a light flux onto a recording layer through a transparent substrate. The apparatus includes one or a plurality of optical heads having a plurality of objective lenses whose aberrations have respectively been corrected for a plurality of disc substrates of different thicknesses, a cartridge for enclosing the optical disc, a discrimination hole which is formed on the cartridge, and a sensor for detecting the opening/closing state of the discrimination hole and for generating a discrimination signal. In accordance with the result of the discrimination as to the thickness of the loaded optical disc, the objective lens, in which the occurrence of the aberration is smallest, is used, so that the information signal can preferably be recorded, reproduced or erased onto/from the optical discs having different substrate thicknesses.