Abstract: Provided are an optical connector and an optical tomographic imaging apparatus, by which no noise occurs and a high quality image without a distortion can be obtained. In the optical connector, optical fibers are inserted into a lumen of a tube from opposite ends thereof; one of the optical fibers is fixed to the tube and the other optical fiber is held so as to be rotatable relative to the tube; an end of one of the optical fibers is separated from an end of the other optical fiber to form a gap therebetween in the lumen; a connecting section which connects the exterior space of the tube and the gap is formed; and a liquid or fluid made of a material which can transmit light is held in the exterior space, the gap, and the connecting section.

Abstract: A light source unit includes a light source element; an optical-waveguide-formed element in which an optical waveguide is formed; a prism for turning back a light flux emitted from the light source and guiding the light flux toward an incident end of the optical waveguide; and a coupling optical system formed on the prism or provided as a separated body from the prism, for coupling the light flux emitted from the light source onto the optical waveguide.

Abstract: An optical tomographic image forming method including: splitting low coherence light emitted from a light source is split into a measuring light and a reference light; forming an optical tomographic image of a measured object by detecting an interference light that is obtained by superposing reflected light, reflected from the measured object when the measuring light is irradiated onto the measured object via a condenser lens, and reflected light, reflected from a reference mirror, which is positioned a predetermined length of optical path away from the splitting position, when the reference light is irradiated onto the reference mirror, wherein the method further includes: inputting a refractive index of the measured object; correcting the tomographic image in accordance with the inputted refractive index of the measured object; and outputting the corrected tomographic image.

Abstract: A semiconductor laser used as a light source of an optical module is susceptible to the return light from the lens surface. The problem has been conventionally solved by offsetting the optical axis of a lens and the optical axis of a semiconductor laser, but a high-precision and costly process for adjusting the positioning is required. An optical module and an optical unit, wherein the oscillation state of a semiconductor laser can be limited in the range of normal characteristics at a low cost, are provided by proposing a lens which eliminates the need for adjusting the positioning because there is little return light. As a first lens on which the light exiting a semiconductor laser impinges at first, a lens having an optical surface whose convex surface faces toward the semiconductor laser side is employed so that the light is diverged thus reducing the intensity of light returning to the semiconductor laser.

Abstract: The present invention provides an optical pickup apparatus to for recording and/or reproducing information on an optical information recording medium including multilayered information recording surfaces. The optical pickup apparatus includes: a light source; an objective lens; a first optical element including a first optical area and a second optical area; a second optical element including a third optical area and a fourth optical area. The optical pickup apparatus further includes a light-converging element for receiving a main light flux from one information recording surface and a secondary light flux from another information recording surface and converging the main light flux at a position between the first optical element and the second optical element. The optical pickup apparatus further includes a polarization splitting optical member for splitting the main light flux and the secondary light flux; and a photodetector for receiving the main light flux.

Abstract: An optical pickup apparatus includes: a first light source for emitting a first light flux; a light-converging optical system including an objective lens and a diffractive structure. When the first light flux from an optical information recording medium enters into the diffractive structure, the diffractive structure emits a main light flux and a secondary light flux. The optical pickup apparatus further includes: a first optical element including a first optical area and a second optical area; a second optical element including a third optical area and a fourth optical area; a light-converging element for converging the main light flux at a position between the first optical element and second optical element; a polarization splitting optical member for splitting the main light flux and the secondary light flux each emitted from the first optical element and second optical element; and a photodetector for receiving the main light flux.

Abstract: A light source unit relating to the present invention includes a light source element; an optical-waveguide-formed element in which an optical waveguide is formed; a prism for turning back a light flux emitted from the light source and guiding the light flux toward an incident end of the optical waveguide; and a coupling optical system formed on the prism or provided as a separated body from the prism, for coupling the light flux emitted from the light source onto the optical waveguide.

Abstract: Methods of optimizing optical alignment in an optical package are provided. In one embodiment, the optical package includes a laser diode, a wavelength conversion device, coupling optics positioned along an optical path extending from the laser diode to the wavelength conversion device, and one or more adaptive actuators. The method involves adjusting the optical alignment of the wavelength conversion device in a non-adaptive degree of freedom by referring to a thermally-dependent output intensity profile of the laser diode and a thermally-dependent coupling efficiency profile of the optical package.

Abstract: The present invention relates to an optical coupling lens and light source module. An optical coupling lens is provided for converging a light flux emitted from a light source to an entrance aperture. The optical coupling lens satisfies a predetermined condition according to a third-order astigmatisms coefficient of the optical coupling lens. A light source module includes: a light source; an optical waveguide; and an optical unit including one or more of an optical coupling lens for converging a light flux emitted from the light source onto the optical waveguide. At least one optical coupling lens satisfies predetermined condition according to a third-order astigmatism coefficient of the optical coupling lens.

Abstract: The present invention provides a semiconductor light source module including: a semiconductor light source for emitting a light flux with a predefined wavelength; a SHG element for converting an incident light flux entering onto an incident end surface of the SHG element into an outgoing light flux having a different wavelength from the incident light flux; a light converging optical system for converging a light flux emitted from the semiconductor light source onto the incident end surface of the SHG element; a light receiving element for receiving a part of a light flux emitted from the SHG element; and a drive device for driving an optical element in the light converging optical system based on a light flux received by the light receiving element.

Abstract: An optical pickup apparatus is provided for recording and/or reproducing information on an optical disc including at least one reference layer and at least one recording layer in which information can be recorded at recording positions each located at a different distance from an optical disc surface. The optical pickup apparatus includes: a light source; a relay lens system for emitting a converged light flux; an objective lens arranged at a predetermined distance from the reference layer, for converging the converged light flux onto one of the recording positions; and a photodetector. The relay lens system changes a convergence angle of the converged light flux to enter the objective lens by moving in a direction of an optical axis thereof so as to select a recording position where information is recorded and/or reproduced.

Abstract: The present invention relates to an optical coupling lens and light source module. An optical coupling lens is provided for converging a light flux emitted from a light source to an entrance aperture. The optical coupling lens satisfies a predetermined condition according to a third-order astigmatisms coefficient of the optical coupling lens. A light source module includes: a light source; an optical waveguide; and an optical unit including one or more of an optical coupling lens for converging a light flux emitted from the light source onto the optical waveguide. At least one optical coupling lens satisfies predetermined condition according to a third-order astigmatism coefficient of the optical coupling lens.

Abstract: An optical communication module includes a first light-receiving element with a receiving surface in which a light flux with a wavelength ?1 emitted from an end surface of an optical fiber enters; a light-emitting element for emitting a light flux with a wavelength ?2; and a first optical element arranged between the first light-receiving element and the light-emitting element, and the end surface of the optical fiber. The first optical element includes a first optical surface with a positive refractive power and a second optical surface having a diffractive structure. One of the first optical surface and the second optical surface is divided into at least a first optical functional surface and a second optical functional surface through a step difference.

Abstract: An optical pickup apparatus includes: a first light source for emitting a first light flux; a light-converging optical system including an objective lens and a diffractive structure. When the first light flux from an optical information recording medium enters into the diffractive structure, the diffractive structure emits a main light flux and a secondary light flux. The optical pickup apparatus further includes: a first optical element including a first optical area and a second optical area; a second optical element including a third optical area and a fourth optical area; a light-converging element for converging the main light flux at a position between the first optical element and second optical element; a polarization splitting optical member for splitting the main light flux and the secondary light flux each emitted from the first optical element and second optical element; and a photodetector for receiving the main light flux.

Abstract: The present invention provides an optical pickup apparatus to for recording and/or reproducing information on an optical information recording medium including multilayered information recording surfaces. The optical pickup apparatus includes: a light source; an objective lens; a first optical element including a first optical area and a second optical area; a second optical element including a third optical area and a fourth optical area. The optical pickup apparatus further includes a light-converging element for receiving a main light flux from one information recording surface and a secondary light flux from another information recording surface and converging the main light flux at a position between the first optical element and the second optical element. The optical pickup apparatus further includes a polarization splitting optical member for splitting the main light flux and the secondary light flux; and a photodetector for receiving the main light flux.

Abstract: The present invention provides a semiconductor light source module including: a semiconductor light source for emitting a light flux with a predefined wavelength; a SHG element for converting an incident light flux entering onto an incident end surface of the SHG element into an outgoing light flux having a different wavelength from the incident light flux; a light converging optical system for converging a light flux emitted from the semiconductor light source onto the incident end surface of the SHG element; a light receiving element for receiving a part of a light flux emitted from the SHG element; and a drive device for driving an optical element in the light converging optical system based on a light flux received by the light receiving element.

Abstract: An optical communication module includes a first light-receiving element with a receiving surface in which a light flux with a wavelength ?1 emitted from an end surface of an optical fiber enters; a light-emitting element for emitting a light flux with a wavelength ?2; and a first optical element arranged between the first light-receiving element and the light-emitting element, and the end surface of the optical fiber. The first optical element includes a first optical surface with a positive refractive power and a second optical surface having a diffractive structure. One of the first optical surface and the second optical surface is divided into at least a first optical functional surface and a second optical functional surface through a step difference.

Abstract: An optical unit for an optical pickup apparatus for recording and or reproducing information onto or from the first to third optical recording media by applying the first to third light beams emitted from the first to third light sources, the optical unit comprises a mirror having dichroic mirror layer including reflecting surfaces 71a and 70a on both surfaces and an objective lens including a phase structure on the optical surface of the objective lens. The reflecting surface 71a of the mirror reflects the first to second light beams and guides them to the objective lens. Reflecting surface 70a reflects the third light beams and guides them to the objective lens. The phase structure on the objective lens corrects the spherical aberration of the first and the second light beams, and focuses the first light beams onto BD, the second beams onto DVD and the third beams onto CD.

Abstract: Circuit ends of a cancel loop circuit and a frequency generator circuit are connected with circuit lands in such a manner that the two circuits are not allowed to electrically communicate with each other. The cancel loop circuit and the frequency generator circuit are subjected to an electrical conductivity test to detect any short circuit therebetween. After successful testing, the lands located adjacent each other at one side of the circuits are connected with each other, thereby electrically communicating the cancel loop circuit and the frequency generator circuit to obtain a completed coil circuit.