Abstract: An optical pickup device includes a semiconductor laser for emitting forward and backward laser light from front and back emergent end faces thereof, focusing device for focusing the forward laser light emergent from the front emergent end face of said semiconductor laser onto an optical recording medium, a light-receiving element for signal reproduction for detecting return light from the optical recording medium, and a light-guiding system for guiding the return light to said light-receiving element for signal reproduction, said optical pickup device being provided with a light source unit having an arrangement in which said semiconductor laser and said light-receiving element for signal reproduction being incorporated in a common package and shielding device, disposed inside said package of said light source unit, for preventing the light emitted from said semiconductor laser from being incident upon said light-receiving element for signal reproduction.

Abstract: A light source device for an optical head apparatus comprises at least one laser diode chip and a semiconductor substrate integral with the laser chip. The light source device is formed in a recess of the semiconductor substrate for aligning the laser diode chip on a surface of the semiconductor substrate by a semiconductor processing technique. The recess comprises a first side surface for defining a laser beam emitted from the laser diode chip in an optical axial direction and a second side surface for defining a direction perpendicular to the optical axial direction.

Abstract: A laser beam emission apparatus that may be used as a universal optical pickup laser light source. The apparatus may be used in various applications including recording/reproduction of data to/from various types of optical disks in various recording/reproducing modes. The apparatus includes a first semiconductor laser chip that emits a first laser beam at a first wavelength, and a second semiconductor laser chip that emits a second laser beam at a second wavelength different from the first wavelength. The emitted second laser beam has a plane of polarization that is perpendicular to the plane of polarization of the emitted first laser beam. The apparatus further includes a polarized beam splitter that transmits one of the laser beams and reflects the other laser beam, and a semiconductor substrate that has the laser chips and the polarized beam splitter mounted thereon.

Abstract: An optical pickup device includes a light source irradiating a record medium with plural light spots of light emitted therefrom, a plurality of light detecting elelments to which reflected light of the light spots are guided, respectively, to adequately synthesize and compare outputs of said light detecting elements, thereby reading information recorded in tracks of the record medium, and detecting an tracking error and a focusing error, and a hologram element which splits light emitted from the light source into plural beams is disposed in an optical path between the light source and the record medium, said hologram element is split by a split line, said split line elongating in a direction perpendicular to a track of the medium on an optical axis, and a hologram pattern having a diffraction function which is substantially directed in the track direction is disposed on at least one side of said split line, thereby differentiating diffraction conditions on both sides of said split line from each other.