Abstract: An optical element is provided that includes a base substrate, a waveguide substrate, and a thin film layer that is provided between the base substrate and the waveguide substrate and that has a single-layer structure of a multilayer structure including a film containing Ta2O5 or Nb2O5 as a principal component.

Abstract: A light generating apparatus includes: a submount; a semiconductor laser chip mounted on the submount; a substrate which is mounted on the submount and includes an optical waveguide; and a substance having a predetermined thickness which is disposed between the semiconductor laser chip and the substrate. In an oscillation wavelength stabilizing apparatus for a light source, the light source is a semiconductor laser which includes: an active region for providing gain; and a distributed Bragg reflection (DBR) region for controlling an oscillation wavelength.

Abstract: The emission angle and emission position of coherent light source are controlled with high precision. A wavelength-variable DBR semiconductor laser (1) and an optical waveguide-type QPM-SHG device (2) are mounted on a submount (7), and the submount (7) is fixed inside a package (11), thus obtaining a coherent light source. Reference lines (A) and (B) serving as reference markers when fixing the submount (7) are formed on a submount fixing face of the package (11).

Abstract: An optical waveguide element includes a three-dimensional optical waveguide of a bulky non-linear optical crystal, a substrate, and a joining layer made of an amorphous material. The substrate is joined to the optical waveguide via the joining layer.

Abstract: The invention provides a method for manufacturing an optical waveguide device, with which the thickness of an optical substrate can be controlled with high precision. The surface of a substrate is masked by applying a resist to all regions of the substrate except where stopper portions are to be formed (i.e. to the left and right in width direction of the substrate). Then, the stopper portions are formed on the surface of the substrate by sputtering/vapor deposition of Cr, and then the resist is removed. Using a UV curing resin, an Mg-doped LiNbO3 optical substrate is laminated between the pair of stopper portions to the left and right of the surface of the substrate. After laminating the optical substrate, which is made of a non-linear optical material, the optical substrate is abraded.

Abstract: A light generating apparatus includes: a submount; a semiconductor laser chip mounted on the submount; a substrate which is mounted on the submount and includes an optical waveguide; and a substance having a predetermined thickness which is disposed between the semiconductor laser chip and the substrate. In an oscillation wavelength stabilizing apparatus for a light source, the light source is a semiconductor laser which includes: an active region for providing gain; and a distributed Bragg reflection (DBR) region for controlling an oscillation wavelength.

Abstract: An optical waveguide of the present invention includes: a nonlinear optical crystal; a first ion exchange region provided in the vicinity of a portion of a surface of the nonlinear optical crystal; and a second ion exchange region provided in the surface of the nonlinear optical crystal. The second ion exchange region covers a greater area of the surface than an area covered by the first ion exchange region. The second ion exchange region includes a region having an extent of 0.02 &mgr;m to 0.2 &mgr;m along a depth direction in which an ion exchange ratio varies along the depth direction.

Abstract: The present invention aims to simplify a mass production process of an optical waveguide device and to reduce cost as well as noise. The optical waveguide device includes an optical waveguide whose entrance end face and exit end face are substantially parallel to each other. A SHG device is mass-produced by optically polishing an optical material substrate with a large area and then cutting the substrate. This method can mass-produce the optical waveguide devices having a uniform device length. The angle between the exit end face of the optical waveguide and the direction of an optical axis of the optical waveguide at the exit end face is not 90°, thereby reducing return light from the exit end face.

Abstract: An optical waveguide device comprises a substrate having first and second surfaces, and an optical waveguide provided on the first surface of the substrate, having a light-incoming facet and a facet inclined with respect to the optical waveguide. Guided light incident to the optical waveguide through the light-incoming facet is totally reflected off the inclined facet, and the guided light is transmitted through the first or second surface of the substrate.

Abstract: A laser beam as fundamental waves which is emitted from a distribution Bragg reflection (DBR) semiconductor laser is incident on an optical waveguide of a light wavelength conversion device in which domain-inverted regions and the optical waveguide are formed in an LiTaO3 substrate. The wavelength of the incident laser beam is then converted so as to obtain higher harmonic waves such as blue light. In the conversion, a drive current to be applied to a DBR portion of the DBR semiconductor laser is changed so as to change an oscillating wavelength of the DBR semiconductor laser, thereby matching the oscillating wavelength with a phase-matched wavelength of the light wavelength conversion device. Thus, the generation of the harmonic waves to be output is stably controlled.

Abstract: An optical waveguide device is provided that can reduce external interference noise. The optical waveguide device includes a substrate, an optical waveguide formed on the substrate, a periodic polarization inversion region formed on the optical waveguide, and an optical thin film formed in a portion of the optical waveguide. The optical waveguide (refractive index: N2) and the optical thin film (refractive index: N1) differ in refractive index dispersion, and the magnitude relationship between the refractive indexes is reversed depending on wavelength. The relationship N1>N2 is established for light having a shorter wavelength, while the relationship N2>N1 is established for light having a longer wavelength.

Abstract: A laser beam as fundamental waves which is emitted from a distribution Bragg reflection (DBR) semiconductor laser is incident on an optical waveguide of a light wavelength conversion device in which domain-inverted regions and the optical waveguide are formed in an LiTaO3 substrate. The wavelength of the incident laser beam is then converted so as to obtain higher harmonic waves such as blue light. In the conversion, a drive current to be applied to a DBR portion of the DBR semiconductor laser is changed so as to change an oscillating wavelength of the DBR semiconductor laser, thereby matching the oscillating wavelength with a phase-matched wavelength of the light wavelength conversion device. Thus, the generation of the harmonic waves to be output is stably controlled.

Abstract: An optical waveguide device includes a dielectric substrate; and an optical waveguide formed in the dielectric substrate, the optical waveguide having a longitudinal axis and an outgoing surface disposed at an angle other than a right angle relative to a plane perpendicular to the longitudinal axis.

Abstract: A method for forming a ferroelectric domain-inverted structure, having the steps of joining at least two kinds of ferroelectric material which have different spontaneous polarizations, and ferroelectric domain-inverting one of the ferroelectric materials and thereby ferroelectric domain-inverting the other ferroelectric material joined thereto.

Abstract: After forming domain inverted layers 3 in an LiTaO3 substrate 1, an optical waveguide is formed. By performing low-temperature annealing for the optical wavelength conversion element thus formed, a stable proton exchange layer 8 is formed, where an increase in refractive index generated during high-temperature annealing is lowered, thereby providing a stable optical wavelength conversion element. Thus, the phase-matched wavelength becomes constant, and variation in harmonic wave output is eliminated. Consequently, with respect to an optical wavelength conversion element utilizing a non-linear optical effect, a highly reliable element is provided.

Abstract: An optical waveguide element is disclosed, which includes a three-dimensional optical waveguide of a bulky non-linear optical crystal, a substrate, and a joining layer made of an amorphous material through which the substrate is joined to the optical waveguide.

Abstract: An optical pickup and an optical information recording/reproducing device are provided, each of which is capable of forming a super-resolution spot to conduct micro-mark recording, and does not undergo signal degradation due to an increased sidelobe in a reproducing operation. A variable phase filter having three regions to produce a phase difference in a radial direction is used, to provide a phase difference of &pgr; between the center region and the side regions in a recording operation, so that a super-resolution spot is formed on a recording layer of the optical disk. In a reproducing operation, a phase difference is nullified between the regions of the variable phase filter, so that a normal light spot at a diffraction limit having a smaller sidelobe is formed. The variable phase filter can be formed with a homogeneous-alignment liquid crystal element.

Abstract: After forming domain inverted layers 3 in an LiTaO3 substrate 1, an optical waveguide is formed. By performing low-temperature annealing for the optical wavelength conversion element thus formed, a stable proton exchange layer 8 is formed, where an increase in refractive index generated during high-temperature annealing is lowered, thereby providing a stable optical wavelength conversion element. Thus, the phase-matched wavelength becomes constant, and variation in harmonic wave output is eliminated. Consequently, with respect to an optical wavelength conversion element utilizing a non-linear optical effect a highly reliable element is provided.

Abstract: A wavelength-variable semiconductor laser includes: a submount; and a semiconductor laser chip being mounted onto the submount and having at least an active layer region and a distributed Bragg reflection region, wherein the semiconductor laser chip is mounted onto the submount in such a manner that an epitaxial growth surface thereof faces the submount and a heat transfer condition of the active layer region is different from a heat transfer condition of the distributed Bragg reflection region. Moreover, an optical integrated device includes at least a semiconductor laser and an optical waveguide device both mounted on a submount, wherein the semiconductor laser is the wavelength-variable semiconductor laser as set forth above.

Abstract: A wavelength-variable semiconductor laser includes: a submount; and a semiconductor laser chip being mounted onto the submount and having at least an active layer region and a distributed Bragg reflection region, wherein the semiconductor laser chip is mounted onto the submount in such a manner that an epitaxial growth surface thereof faces the submount and a heat transfer condition of the active layer region is different from a heat transfer condition of the distributed Bragg reflection region. Moreover, an optical integrated device includes at least a semiconductor laser and an optical waveguide device both mounted on a submount, wherein the semiconductor laser is the wavelength-variable semiconductor laser as set forth above.