Abstract: Embodiments described herein relate to a large area lens-free imaging device. One example is a lens-free device for imaging one or more objects. The lens-free device includes a light source positioned for illuminating at least one object. The lens-free device also includes a detector positioned for recording interference patterns of the illuminated at least one object. The light source includes a plurality of light emitters that are positioned and configured to create a controlled light wavefront for performing lens-free imaging.

Abstract: A novel multi-junction detector device and method of use is disclosed, which includes a housing, at least one mount system body positioned within the housing, at least one beam dump region formed in the mount system body, with a first detector having a first wavelength responsivity range positioned on the mount system body and at least a second detector having a second wavelength responsivity range positioned on the mount system body in optical communication with the first detector.

Abstract: An optical system capable of obtaining a high-resolution image using interference and thus capable of providing a stable signal is realized. A particular polarization state of response light emitted from an object is selected, and light in the selected particular polarization state is split into two beams. The split two beams are polarized into two different polarization states. After one of the two beams is subjected to an image inversion, the two beams are condensed such that they interfere with each other. The interfering light is split into a plurality of beams, and each of these beams is detected after they are passed through different polarizing filters. Detected signals are combined together and processed to obtain high-stability amplitude information without being influenced by a phase difference between the two beams.

Abstract: A system and method for providing direct read after write functionality in an optical data storage device include an optical head having a first coherent light source modulated at higher power during writing of data to the optical medium and a second coherent light source operating in a continuous wave mode at lower power while the first coherent light source is writing data. Optic components combine light from the first and second light sources and focus light from the first coherent light source to a first spot of a selected track on the optical medium and focus light from the second coherent light source to a second spot on the selected track downstream from the first spot relative to movement direction of the optical medium to read and verify the data directly after writing during the write process rather than in a separate verification process.

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: There is disclosed an optical information recording device using a multilayer optical disc as a recording medium, in which the number of components of the device is reduced. The optical disc has, e.g., one recording layer with prepits and a plurality of recording layer without prepits. An optical pickup included in the information recording device includes a switchable lens element to focus laser beams to be applied to the multilayer optical disc onto two adjoining recording layers. A tracking error signal offset obtained for a recording layer with prepits is stored. Recording an information signal into a recording layer from which a tracking error signal cannot be detected is performed, while maintaining the accuracy of positioning on track with respect to the prepits based on the stored offset. When reading out an information signal, tracking control based on the prepits of recorded information signals is exerted.

Abstract: An optical pickup device includes a polarization diffraction grating to diverge an optical beam reflected from an optical disc and an optical detector to receive the optical beam diverged by the polarization diffraction grating, a polarization of 0 order diffracted light diffracted through the polarization diffraction grating is substantially perpendicular to that of a +1 order diffracted light diffracted therethrough, and a polarization filter having a plurality of domains is mounted between the polarization diffraction grating and the optical detector.

Abstract: The invention relates to a method of optical six-dimensional data storage and the apparatus based on it. This invention uses multiple beams with different wavelengths, encoded intensities and polarizations to create each group of multiple wavelength selective, reflectivity specified and polarization sensitive tiny plane or quasi-plane Bragg reflectors in a small volume crossing through multiple storage medium layers as each storage cell. The maximum storage capacity can over 10 Terabytes per disk with fast data write, read and erase speeds. In addition, the apparatus based on this method has no interlayer noise and disk rotation caused data recoding and reading quality loss, and has good compatibility with existing CD and DVD disks.

Abstract: An optical-pickup apparatus includes: a laser-light-source unit to emit a laser beam having a first or second wavelength selectively; an objective lens; a photodetector; a light-splitting unit to split first and second laser beams respectively emitted from the laser-light-source unit and an optical-recording medium according to a wavelength and polarization direction, and guide the first and second laser beams to the lens and photodetector, respectively; and a quarter-wave plate arranged between the light-splitting unit and lens to convert the laser beams having the first and second wavelengths incident thereon through the light-splitting unit, from linearly-polarized light to circularly-polarized light and from linearly-polarized light to elliptically-polarized light, respectively, the laser beam having the second wavelength being incident, as first linearly-polarized light, on the light-splitting unit, and the light-splitting unit performing phase shift for the laser beam having the second wavelength incide

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: In an optical pickup device for a simple optical system, a light beam emitted from a laser diode is split into first and second light beams by a polarized beam splitter, an optical disc is irradiated with the first light beam to obtain signal light, and the second beam is reflected by a reflection element to obtain reference light. Light beams of the signal light and the reference light are synthesized into one light beam, the synthesized light beam is separated into four light beams by a phase difference forming unit including a grating, a divided wave plate and a polarization grating, and different phase differences are afforded to the signal light and the reference light in each light beam. The four light beams are detected by one detector to generate the reproduction signal.

Abstract: An optical pickup apparatus includes a light generating unit to generate a light to record or reproduce information, an objective lens to focus the light generated from the light generating unit onto a disk, and a multi-sectional polarizer disposed on a light path between the light generating unit and the objective lens and divided into a plurality of sectors having their individual optical axes.

Abstract: A polarization detection system structured for optical read-out of disc-shaped optical data/information storage and retrieval media with surfaces comprised of pits or marks configured as multilevel oriented nano-structures (ONS) with varying pit or mark orientations and widths. The polarization detection system comprises: an optical beam source; a stage for mounting and rotating an optical disc medium about a central axis; at least one photodetector; a beam splitter positioned in an optical path between the source and stage, for directing an incident beam from the source onto an optical disc mounted on the stage and a return beam from the disc onto the photodetector; and an optical polarizer positioned in an optical path between the beam splitter and the at least one photodetector, for detection and analysis of changes in polarization of the return beam effected by variation of the orientation of the walls and/or widths of the pits or marks of the disc.

Abstract: A recording medium, a recording/reproducing apparatus, and a recording/reproducing method are disclosed. The apparatus uses the number of record layers contained in a recording medium and a multi-wavelength light source including a plurality of optical signals having different wavelengths, and irradiates an optical signal emitted from a light source on each recording medium according to wavelengths of the light beams. As a result, the apparatus can effectively gain access to the recording medium including a plurality of record layers, such that it can simultaneously record/reproduce data in/from the recording medium.

Abstract: There is provided an optical head which have no such problems regarding increase in cost and size thereof and can reduce errors by suppressing crosstalk components attributable to reflection on lands of a magneto-optical recording medium and thereby prevent degradation of reproduction characteristics. An optical element includes a light separating section for separating outgoing light and return light, and a phase compensation section for imparting phase compensation to light incident thereon. The optical element is provided on a light path of return light between an objective lens and a photodetector, so as to be closer to the photodetector than the light separating section is. This makes it possible to impart the phase compensation to the return light and prevent the degradation of reproduction characteristics. Light separating elements such as beam splitter are no more necessary in the configuration, with the result that decreases in size and cost can be realized.

Abstract: In multilayer optical discs and high-speed optical discs, the amount of reproduction light per unit time greatly decreases and the reproduction signal quality (S/N) significantly drops due to the low effective reflectivity and the short read time of the medium. These problems are solved by causing reflected signal light from the optical disc and reference light, which is separated from the same light source and introduced into a detector without being shone onto the optical disc, to interference with each other on the detector. Detector outputs having four different interference states are simultaneously obtained, the interference states being displaced at intervals of 90° in terms of the phase relationship between the reference light and the signal. Based on a operation of the four detector outputs, a reproduction signal can be obtained that is stable at all times and amplified with high quality, even when there is an optical path length variation due to disc undulations.

Abstract: A method capable of detecting spherical aberration caused by a storage medium includes generating a plurality of light beams having distinct phases by diffracting light emitted from a light source using a diffractive optical element, measuring optical signals of the plurality of light beams having distinct phases after being reflected by the storage medium, measuring optical signals of the plurality of light beams having distinct phases after being reflected by a reflective mirror, and updating settings of an adjusting device disposed on an optical path between the diffractive optical element and the storage medium in order to compensate for the spherical aberration caused by the storage medium.

Abstract: An optical pickup device and an optical recording and reproducing apparatus are suitable for use with a near-field optical recording and reproducing system. An optical pickup device comprises an objective lens composed of a solid immersion lens (SIL) the objective lens having a numerical aperture greater than 1, a beam splitter configured to reflect both of a p-polarized light component and an s-polarized light component of reflected lights from an optical recording medium when the optical pickup device irradiates the optical recording medium with a bundle of rays in a predetermined polarized state from a light source through the objective lens, a divider configured to divide incident light into a p-polarized light component and an s-polarized light component reflected by the beam splitter, and a photo-detector configured to separately detect the p-polarized light component and the s-polarized light component divided by the divider.

Abstract: A pickup for a magneto-optical recording medium is provided, which improves quality of reproduced signals by eliminating a phase difference between the polarizations and is capable of coping with magneto-optical recording media of different recording/reproducing systems. A return light beam of light reflected by a magneto-optical recording medium is polarized and separated into ± first-order diffracted lights through a light-branching diffraction element provided between a light source and an objective lens. The ± first-order diffracted lights are compensated for their phases through first and second phase compensation elements so that there is no phase difference between the polarizations, and are, further, polarized and separated through the first and second polarization/separation elements, and are received by first and second light detectors.

Abstract: A prism includes a plurality of internal surfaces that reflect a beam incident on the prism.

Abstract: An optical pickup device and an optical recording and reproducing apparatus are suitable for use with a near-field optical recording and reproducing system.

Abstract: An optical scanning device for scanning a dual-layer optical record carrier. The device includes a spherical aberration compensation optical subsystem having a switchable liquid crystal cell (10) for altering a wavefront deviation generated in a folding mirror (32) including a non-periodic phase structure (NPS) located behind a polarization-selective reflective layer.

Abstract: An optical pickup unit includes first and second light sources of first and second wavelengths, respectively, a dichroic element, a phase plate, and an objective lens. One of the first and second light sources is selected so that information recording or reproduction is performed by converging a light beam emitted from the selected one of the first and second light sources on an optical recording medium via the dichroic element, the phase plate, and the objective lens.

Abstract: Holographic recording and reproducing using a compact configuration provides no reduction in the recording/reproducing capability. Information light and recording-specific reference light having a spatially modulated phase are generated and projected onto an optical recording medium coaxially that converge on a reflecting surface of a recording medium. P-polarized recording-specific reference light and S-polarized information light are each optically rotated by a two-way split optical rotation plate in directions different between respective half areas of the cross section of the beam thereof.

Abstract: An optical device including a light source for emitting diverging light, a polarizing beam splitter for transmitting or reflecting the diverging light according to a polarized light component, a collimator lens for converting the diverging light transmitted through the polarizing beam splitter into collimated light, and an objective lens for focusing the collimated light on an object. The optical device further includes an optical element arranged between the collimator lens and the objective lens for producing a phase difference of +90°±15° or ?90°±15° between P-polarized light and S-polarized light. The optical element has a principal axis perpendicular or parallel to a plane of incidence of the diverging light on the polarizing beam splitter. For example, the optical element is provided by a quarter-wave plate having an optic axis perpendicular or parallel to the plane of incidence of the diverging light on the polarizing beam splitter.

Abstract: An optical disc device of the present invention includes spherical aberration changing means for changing spherical aberration occurring on a converging position of a light beam converged by a lens, an actuator for moving the spherical aberration changing means in a relatively precise manner, and an actuator for moving the spherical aberration changing means in a relatively rough manner. The optical disc device drives a second actuator and a third actuator based on a signal of spherical aberration detecting means and performs control so that spherical aberration is almost 0. The third actuator moves the spherical aberration changing means based on a direct current component included in a signal of the spherical aberration detecting means, and the second actuator moves the spherical aberration changing means based on an alternating current component included in the signal of the spherical aberration detecting means.

Abstract: An optical pick-up device includes a light source (2), a polarized light beam converter (4), a splitter (6), a collimating lens (7), and a photo-detector (9). A linear polarized light beam with a first type of polarized component and a second type of polarized component is emitted from the light source, and passes through the polarized light beam converter. The first type of polarized component is converted into the second type of polarized component by the polarized light beam converter. Then part of the light beam with the second type of polarized component passes through the splitter and is focused onto an optical disc (8) by the collimating lens. The optical disc reflects the light beam that contains recorded information read from the optical disc. The reflected light beam passes back through the collimating lens, is reflected by the splitter, and is received by the photo-detector.

Abstract: An optical pickup device and an optical recording and reproducing apparatus are suitable for use with a near-field optical recording and reproducing system.

Abstract: The present invention provides an optical device that eliminates side lobes or their components from a super-resolution optical spot, and that is capable of electrically switching between super resolution and normal resolution as needed in simple manner. The optical device having a light generating unit for generating incident light and a lens system for collecting the incident light and producing a super-resolution optical spot containing a main lobe and a side lobe by modulating a portion of the incident light, comprises a polarization vector modulation unit for making polarization vectors of the side lobe and the main lobe differ from each other so that one or the other of the polarization vectors can be selected, and a polarization selective unit for eliminating the side lobe by selecting the polarization vector of the main lobe.

Abstract: An optical element that receives a first incident light and a second incident light through a main surface and allowing the first and second incident lights to be transmitted therethrough, the first and second incident lights being linearly polarized lights having substantially orthogonal polarizing directions and having different wavelengths &lgr;1 and &lgr;2 respectively, the optical element receiving a first reflected light and a second reflected light generated when the first and second incident lights are reflected from a reflector through the other face, and allowing the first and second reflected lights to be transmitted therethrough again, the optical element has a polarizing hologram that allows the first incident light, the second incident light, and the second reflected light to be transmitted therethrough upon receiving these lights and that diffracts the first reflected light upon receiving this light; and at least one wavelength plate that varies at least one of polarizing states of all of the f

Abstract: A phase difference plate (12) converts states of polarization of emergent light form a laser light source (13) and return light form an optical recording medium (5). A diffractive element (21) separates the return light from an optical axis leading from the laser light source (13) to the optical recording medium (5), and guides the return light to a photodetector (14) on the basis of a difference between the states of polarization of the emergent light and the return light. The polarization direction of emergent light from the laser light source (13) is arranged so as to be oriented in the radial direction of the optical recording medium (5) (in the direction of birefringence of the optical recording medium).

Abstract: A magneto-optical recording medium includes a first magnetic layer and a second magnetic layer. The first magnetic layer is an in-plane magnetized film at room temperature, but changes to a perpendicular magnetized film at a predetermined temperature higher than room temperature, and is thin enough to allow a light beam to pass through it. The second magnetic layer has perpendicular magnetic anisotropy and is arranged to allow magnetic coupling to the first magnetic layer when a light beam for reproduction comes from the first magnetic layer side. The rotation of the polarization plane of a light beam which is reflected off the first magnetic layer and the rotation of the polarization plane of the light beam which passed through the first magnetic layer and reflected off the second magnetic layer compensate each other, thereby canceling each other.

Abstract: An optical pickup device for an AS-MO disk, a DVD and a CD includes a dual wavelength semiconductor laser with first and second oscillation devices, a polarization plane rotary unit selectively rotating a plane of polarization of a laser beam 90°, and a polarization selective diffraction grating passing a laser beam straight forward or dividing a laser beam into three beams depending upon the direction of polarization. The optical pickup device operates by the DPP tracking system where three laser beams are directed for an AS-MO disk, and by the DPD tracking system where a single laser beam is directed for a DVD or a CD. As a result, a signal can be reproduced from an AS-MO disk, a DVD, or a CD having different tracking systems.