Abstract: A method for producing an optical device having a polyimide film through which a light beam is transmitted, which comprises applying a solution containing a polyamic film-forming starting material on a substrate and then baking the resultant under vacuum to form the polyimide film.

Abstract: A two-way optical communication device for use in a two-way optical communication system for transmitting and receiving an optical signal via a single optical fiber, comprises a light emitting element for generating transmitted light, a photodetector for receiving incoming light emitted from the optical fiber, and a reflection mirror made of a thin film having a high reflectance, having first and second surfaces, the first surface being opposite to the second surface. An optical member including the reflection mirror is provided closer to the optical fiber than the light emitting element. The incoming light emitted from the optical fiber is reflected by the first surface of the reflection mirror to be guided to the photodetector. The transmitted light emitted from the light emitting element or the transmitted light reflected by an end surface of the optical fiber is reflected by at least a portion of the second surface of the reflection mirror to prevent the transmitted light from entering the photodetector.

Abstract: A method for producing an optical device having a polyimide film through which a light beam is transmitted, which comprises applying a solution containing a polyamic film-forming starting material on a substrate and then baking the resultant under vacuum to form the polyimide film.

Abstract: There is featured a processing method for processing a target body that includes setting a beam area formed by a laser beam on the organic insulating film so as to be larger than an area formed by projecting a target part of an organic insulating film onto a horizontal plane. The method also includes, subsequently moving the organic insulating film toward the irardiated region of the laser beam, and terminating the irradiation with the laser beam when the end part of the target part coincides with the moving end part of the laser beam. This enables the resultant processed target surface to be smooth and free from reaction product including decomposed segments of the target body. Also featured is an optical component including an optical element having a surface that is processed according to the processing methods of the present invention.

Abstract: An objective lens is a single-lens objective lens both surfaces of which are aspherical. The objective lens has a numerical aperture not less than 0.75, and is made of glass satisfying 1.75<n, and 35<v, where n is a refractive index of the glass for at least one of used wavelengths, and v is an Abbe number for a d-lay. With this arrangement, it becomes possible to provide an objective lens which is downsized, has less aberration, and corrects the aberration easily, without a decline in light utilization efficiency; a method for correcting a manufacturing error thereof; and an optical pick-up device using the objective lens.

Abstract: In a two-way optical communication device, a rising mirror bends light transmitted from a light-emitting element in a virtually perpendicular direction to a surface of a substrate, and the light is gathered on an end of an optical fiber via a light-gathering mirror having a curved surface and is coupled to the optical fiber. Further, in the two-way optical communication device, received light, that is propagated from the optical fiber, is reflected on the light-gathering mirror and is gathered on the light-receiving element. The two-way optical communication device can transmit and receive light through a single optical fiber, causing only small loss in transmission and reception, so that light can be efficiently coupled to an optical fiber such as a POF having a large diameter.

Abstract: Bidirectional optical communication devices are attached to both ends of an optical fiber, and each of them has a transmitting light wave guide coupled to a semiconductor laser and a received light wave guide which is coupled to a photodiode, and optically separated from the transmitting light wave guide. On the end face of the light-incident area of the optical fiber on which transmitting light coupled to the optical fiber from the transmitting light wave guide is directed, the light axis of the transmitting light is set so as to tilt with respect to the normal to the end face of the light-incident area so as to prevent reflected light on the end face of the light-incident area caused by the transmitting light from entering the photodiode installed on the same side as the semiconductor laser.

Abstract: A diffraction grating for generating a plurality of beams includes a plurality of gratings. The plurality of gratings are formed to have an axis of symmetry perpendicular to the direction in which a beam is divided on a surface of diffraction grating and include at least two gratings having different fundamental cycles. The plurality of gratings are formed such that they have an axis of symmetry perpendicular to the direction in which a beam is divided on a surface of the diffraction grating, for generating a plurality of beams. The fundamental cycle increases as a function of the distance from the axis of symmetry, and therefore aberration in the periphery of scattering light may be reduced.

Abstract: A diffraction grating for generating a plurality of beams includes a plurality of gratings. The plurality of gratings are formed to have an axis of symmetry perpendicular to the direction in which a beam is divided on a surface of diffraction grating and include at least two gratings having different fundamental cycles. Diffraction grating for generating a plurality of gratings have the plurality of gratings formed such that the gratings have an axis of symmetry perpendicular to the direction in which a beam is divided on a surface of the diffraction grating for generating a plurality of beams and that the fundamental cycle increases as a function of the distance from the axis of symmetry, and therefore aberration in the periphery of scattering light can be reduced.

Abstract: In an optical pickup device, the numerical aperture (NA) of an objective lens is set at 0.7 or more, and the ellipticity of polarized light of a light beam which is incident upon the objective lens is set to be larger than (1.4×NA)−0.7. According to the structure, an optical pickup device which can prevent deterioration of the jitter and crosstalk characteristics, for example, due to oval deformation of a beam spot can be provided.

Abstract: A lightweight, highly reliable optical pickup including a singlet objective lens is offered by correcting coma aberrations which adversely affect properties of the objective lens having an increased NA. A convergent optical system is composed of a singlet objective lens with a NA of 0.75 or more and includes an aberration-correcting optical system which corrects coma aberrations due to an inclination or shift of central axes of both surfaces of the objective lens or an inclination of the objective lens or the optical storage medium to an optical axis of the optical pickup.

Abstract: An optical pickup device which includes an objective lens having a numerical aperture of 0.7 or more collects light emitted from a light source and irradiates an optical recording medium. The objective lens and an antireflection film formed thereon are set so that the intensity of light incident on the outermost rim of the objective lens is 45% or more and 80% or less of the intensity of incident light from the light source to the center of the objective lens. According to the configuration, it is possible to provide an optical pickup device including a high NA objective lens which can suppress a reduction in the light amount at the lens rim.

Abstract: A two-way optical communication device for use in a two-way optical communication system for transmitting and receiving an optical signal via a single optical fiber, comprises a light emitting element for generating transmitted light, a photodetector for receiving incoming light emitted from the optical fiber, and a reflection mirror made of a thin film having a high reflectance, having first and second surfaces, the first surface being opposite to the second surface. An optical member including the reflection mirror is provided closer to the optical fiber than the light emitting element. The incoming light emitted from the optical fiber is reflected by the first surface of the reflection mirror to be guided to the photodetector. The transmitted light emitted from the light emitting element or the transmitted light reflected by an end surface of the optical fiber is reflected by at least a portion of the second surface of the reflection mirror to prevent the transmitted light from entering the photodetector.

Abstract: An optical communication module including: an emission member for emitting a transmission light beam; and a connection member for detachably connecting an optical fiber for external communication with the emission member, the connection member including a tubular accommodation part for coaxially receiving and fixing an end of the optical fiber to be connected, wherein the emission member and the connection member are arranged such that the transmission light beam intersects with an optical axis of the optical fiber at a predetermined angle to enter an end face of the optical fiber when the optical fiber is connected and the transmission light beam collides with an inner wall of the accommodation part when the optical fiber is detached.

Abstract: An optical pickup can be provided, the optical pickup being capable of recording and playback of a plurality of optical disks having different specs by using light beams of different wavelengths, and further being suitable for integrating the semiconductor lasers and light receiving elements into a single package, by including: first and second semiconductor lasers adjacently disposed; a three-beam diffraction grating for generating three beams for tracking control; a second hologram element for diffracting light of the second semiconductor laser to guide it to a photosensor; a complex polarization beam splitter (PBS) for reflecting only light from the first semiconductor laser; and a first hologram element for diffracting light of the first semiconductor laser to guide it to the photosensor.

Abstract: An objective lens is made up of a light-source-side lens and a medium-side lens wherein at least either one of rim portions of respective opposing surfaces of the light-source-side lens and the medium-side lens forms a rise-up section projected towards the other lens, the rim portion which forms the rise-up section and the rim portion of the other lens at least partially contact one another, and these two lens are fixed together by an adhesive resin layer formed in a spacing between the respective rim portions. With the foregoing structure, an objective lens made up of a pair of lenses which has high rigidity as a whole and is capable of high speed recording and reproducing by suppressing adverse effects of resonance can be realized.

Abstract: According to the method of processing in accordance with the present invention, first, a beam area formed by a laser beam on the organic insulating film is set to be larger than an area formed by projecting a target part of an organic insulating film onto a horizontal plane, subsequently, the organic insulating film is moved toward the irradiated region of the laser beam, and the irradiation with the laser beam is terminated when the end part of the target part coincides with the moving end part of the laser beam. This enables the resultant processed target surface to be smooth and free from reaction product including decomposed segments of the target body.

Abstract: There is featured a processing method for processing a target body that includes setting a beam area formed by a laser beam on the organic insulating film so as to be larger than an area formed by projecting a target part of an organic insulating film onto a horizontal plane. The method also includes, subsequently moving the organic insulating film toward the irradiated region of the laser beam, and terminating the irradiation with the laser beam when the end part of the target part coincides with the moving end part of the laser beam. This enables the resultant processed target surface to be smooth and free from reaction product including decomposed segments of the target body. Also featured is an optical component including an optical element having a surface that is processed according to the processing methods of the present invention.

Abstract: A waveguide-photodetector includes a semiconductor substrate; a waveguide section, provided on the semiconductor substrate, for propagating light; an opto-electric converting section, provided in the semiconductor substrate, for converting the light into an electric signal; and an insulative layer provided between the semiconductor substrate and the waveguide section. The waveguide section includes at least an introducing part for introducing the light to the waveguide section, a coupling part for coupling the light introduced to the waveguide section to the opto-electric converting section, and a propagating part for propagating the light from the introducing part to the coupling part. The insulative layer includes a first region for defining a position and a shape of an impurity diffused region of the opto-electric converting section, a second region which encloses the first region and is thicker than the first region, and a step portion between the first region and the second region.

Abstract: A method for producing a tapered waveguide is produced using an undercut-type shadow mask having an overhanging part. The shadow mask includes a photoresist layer having the overhanging part and a metal layer for supporting the photoresist layer on a substrate. After the shadow mask is provided on the substrate, film-forming particles are caused to jump from above the shadow mask toward the substrate, thereby forming a dielectric film having a tapered part on the substrate. Then, the shadow mask is removed together with the film-forming particles thereon by lift-off. Then, an optical waveguide is formed on the substrate so as to cover the dielectric film having the tapered part. The thickness of the metal layer is preferably in the range of about 0.1 to 10 .mu.m and more preferably about 1 .mu.m.