Abstract: An optical integrated circuit for preventing unnecessary optical waves from outside or scattered in a waveguide. The optical integrated circuit has an substrate, a wave guide which has a core layer and at least a clad layer formed on the substrate, in which an optical wave is guided and transmitted, and a cover layer of which material has a high optical wave absorption ratio, which is formed on the waveguide partially or entirely.

Abstract: A focal point position detector has a light source for emitting light; an optical system for converging light from the light source to an optical recording medium; a coupler for coupling light from the optical recording medium thereto; a waveguide concave mirror for converging light from the coupler; a waveguide convex mirror for slightly reducing a converging degree of light from the waveguide concave mirror; and photodetectors for receiving light from the waveguide convex mirror, The coupler, the waveguide concave and convex mirrors and the photodetectors are integrally formed on a substrate, An apparatus for recording and reproducing optical information has a light source; an optical system for converging light emitted from the light source; an optical waveguide; a coupler for coupling the converged light to the optical waveguide; two waveguide mirrors arranged such that reflected light from the coupler is continuously reflected on the waveguide mirrors; and a photodetector for detecting the light reflecte

Abstract: An optical data recording and reproduction apparatus which uses a semiconductor laser as a light source is disclosed. The half angle of light issuing from the laser in a junction direction of the laser and the focal length of a condenser lens adapted to focus a laser beam from the laser are adequately selected in such a manner as to satisfy a particular condition.

Abstract: An apparatus for recording and reproducing optical information includes an optical integration detecting element arranged on an optical path of light from a laser beam source to an optical information recording medium.

Abstract: A magneto-optical signal detection device comprising a thin film type optical waveguide unit having a substrate on which a waveguide is formed. The unit has a coupling portion for coupling two polarization components simultaneously in a same plane of the waveguide as a TE mode and a TM mode. The modes TE and TM are included in reflection light reflected from a magneto-optical recording medium and perpendicular to each other. The unit also has a TE-TM mode separating portion having a taper boundary. A waveguide layer is gradually thinned in the taper boundary toward an outer end thereof.

Abstract: A high efficiency prism coupling device that comprises a substrate, an optical waveguide layer disposed on the substrate, a gap adjuster layer disposed on the waveguide layer and a prism secured to the gap adjuster layer through a dielectric adhesive agent. The gap adjuster layer has a refractive index which is lower than that of the waveguide layer. The gap adjuster layer has a recess formed therein for guiding an incident beam to the waveguide layer through a bottom portion thereof. The adhesive agent is disposed in and around the recess and has a refractive index which is higher than that of the waveguide layer. The prism is made from a dielectric material and disposed above the recess of the gap adjuster layer through the adhesive agent. The prism has a refractive index which is higher than that of the waveguide layer. The incident beam is introduced from outside through the prism, the adhesive agent and the bottom portion of the recess to the waveguide layer.

Abstract: A beam shaping optical system has an optical prism; a gap layer stacked on a reflecting face of the optical prism and having a refractive index lower than that of the optical prism; and a waveguide layer stacked on the gap layer and having a refractive index lower than that of the optical prism and higher than the refractive index of the gap layer, the optical prism, the gap layer and the waveguide layer constituting a prism coupler. The prism coupler is adapted to reflect a collimated light beam made incident to the prism coupler on a stacking face of the optical prism such that the diameter of the incident light beam in a direction parallel to an incident face of the prism coupler is changed to shape the incident light beam, the gap layer and the waveguide layer being stacked on the stacking face. The waveguide layer may be stacked on a transparent substrate and the refractive index of the waveguide layer may be higher than that of the transparent substrate.

Abstract: A waveguide type optical detection apparatus which is provided on an optical integrated circuit that has a waveguide for transmitting a light from point to point through the waveguide, one or more sets of two adjacent photodetectors provided on the waveguide, and one or more light-insensitive areas existing between the two adjacent photodetectors of each set. The waveguide type optical detection apparatus includes a waveguide focusing part and one or more reflection parts, the waveguide focusing part being provided on the waveguide for allowing a light beam passing through the waveguide to be focused on each of the two adjacent photodetectors of each set, and the reflection parts provided adjacent to each of the light-insensitive areas for reflecting each of light beams sent from the waveguide focusing means forward each of the two adjacent photodetectors of each set so that the light beams are received by the photodetectors.

Abstract: An optical pickup device for an optical recording disk having an information recording surface comprises an objective lens for converging a light beam emitted from a light source onto the information recording surface of the disk so as to form a beam spot thereon along an information track of the disk. At least one light detecting unit comprised of a plurality of photodetectors is provided for the detection of focus and tracking errors and the detection of the position of the optical axis of the objective lens. Each of the photodetectors is able to receive a light beam reflected by the information recording surface of the disk and to produce an output signal which is proportional to the amount of the light beam incident thereon.

Abstract: An optical waveguide device which comprises a substrate, an optical waveguide layer formed on the substrate, a gap adjusting layer formed on the optical waveguide layer, a metallic layer formed on the gap adjusting layer to partly cover the gap adjusting layer and having an opening therein, a dielectric adhesive layer disposed in contact with the gap adjusting layer through the opening of the metallic layer, and a dielectric prism disposed on the adhesive layer. The gap adjusting layer has an index of refraction which is lower than that of the optical waveguide layer. An incident light passes through the opeining of the metallic layer. The dielectric adhesive layer has an index of refraction which is higher than that of the optical waveguide layer. The dielectric prism has an index of refraction which is higher than that of the optical waveguide layer.

Abstract: An optical waveguide device includes an optical waveguide extending straight over a predetermined length, a metal cover layer formed on the optical waveguide at least partly and formed with an opening extending therethrough, and a prism fixedly attached to the metal cover film covering the opening. The prism has an index of refraction higher than that of the optical waveguide and the prism receives an incoming light beam and causes the light beam thus received to be coupled into the optical waveguide through the opening. The device may include a substrate on which the optical waveguide is formed with or without a buffer layer therebetween. A photodetector may also be formed integrally with the optical waveguide at one end thereof for detecting light coupled into and propagating along the optical waveguide. Such a device including a photodetector may be used as an optical component of an optical pick-up for use in an optical information recording and reproducing system.

Abstract: A semiconductor laser device having an oscillator for use in a light source containing therein a two- or three-dimensional integrated circuit semiconductor laser element. The laser device comprises a base plate having a top surface, a mask layer having a predetermined pattern provided on the top surface of the base plate, a recessed portion formed by etching the base plate through the pattern of the mask layer, a projecting portion of the mask layer extending over a part of the recessed portion, and a semiconductor laser chip having a side surface or side surfaces emitting a light beam therefrom. The light beam emitted from the side surface of the semiconductor laser chip returns after being reflected by a part of the recessed portion and a part of the projecting portion. In an alternative embodiment, the light beam emitted from the side surface of the semiconductor laser chip is reflected by the inclined plane of the recessed portion and passes through a lens means to produce an output light beam.