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 exemplary optical pickup comprises: first, second and third photosensitive elements which are arranged to respectively receive a main light beam and first and second sub-light beams reflected from an optical storage medium; and fourth and fifth photosensitive elements which are arranged to receive the rest of the light that has also been emitted from a light source but has not been reflected from the optical storage medium. A signal that has been written on the optical storage medium with the main light beam for writing is read by performing an arithmetic operation on the signal output of the second or third photosensitive element and that of the fourth photosensitive element.

Abstract: There are provided an optical head and an optical information device capable of downsizing the optical head, and capable of improving the qualities of a focus error signal, a tracking error signal, and a reproduction signal. A light detector (120) includes a light-receiving unit (121) for receiving a reflected light beam from an optical disc, and a package (125) for covering the light-receiving unit (121). The package (125) has a plurality of light guides (124) formed on a light-receiving surface on the light beam incident side of the light-receiving unit (121), and for guiding a reflected light beam to the light-receiving unit (121), and a light shield (114) for shielding a region except for a plurality of the light guides (124) from light.

Abstract: An optical pickup, an optical disk drive device, an optical information recording device, and an optical information reproduction device in which a reproduction signal, a focus error signal, and a gap error signal can be detected with high accuracy when information is recorded/reproduced on/from an optical information medium having a plurality of information recording layers. The optical pickup includes a focusing lens group (7) that includes a solid immersion lens (8) and focuses the light; a first detection lens (11) that focuses the reflected light from an optical information medium (9) on a first detector (12), and a second detection lens (13) that focuses the reflected light from the flat surface portion of the solid immersion lens (8) on a second detector (14).

Abstract: A method and an apparatus for reading from a near-field optical recording medium are described. The apparatus includes: an optical system for generating a signal beam and a reference beam; a near-field lens for illuminating the signal beam onto the near-field optical recording medium, for collimating a reflected signal beam, and for reflecting the reference beam; and at least a first detector and a second detector for obtaining a homodyne detection signal from the reflected signal beam and the reflected reference beam.

Abstract: A three-dimensional optical memory device comprises an optical disc positioning system, two sources of radiation with wavelengths 21 and 22, a focusing system, an illumination system, focusing system positioning means, a spectrum splitter, an optical sensor, and a control unit. The radiation source with wavelength is an array of laser diodes, which optical axes are parallel and lie in the same plane. The illumination system comprises: a cylindrical lens positioned so that the generatrix of its cylindrical surface is parallel to the plane of the p-n junctions of the laser diodes; a focusing lens; and a stabilizing circuit comprising a beam splitter situated between the focusing lens and the cylindrical lens, a second optical sensor optically coupled to the focusing lens via the beam splitter, and a stabilizer coupled to the focusing lens, wherein the stabilizer and the second optical sensor are electrically connected to the control unit.

Abstract: Provided is an optical pickup apparatus that stably operates by accurately detecting a fluctuation in a light amount of a laser beam caused by movement of a collimating lens. In an optical pickup apparatus of the present invention, part of a laser beam emitted from a laser device is transmitted through a reflective mirror and detected by a laser beam FMD. An output of the laser device is adjusted based on the output from the FMD. Even when a collimating lens moves during the operation of the apparatus, the change in the light amount of the laser beam caused by the movement is immediately detected by the FMD and the output of the laser device is adjusted. Thus, the light amount of the laser beam radiated on an optical information recording medium is kept constant along a time axis. Accordingly, the optical pickup apparatus can stably perform reading and writing.

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

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage.