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 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: 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 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: 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 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. The apparatus includes a control section which monotonously varies, in a first direction, a DBR current to be input to the DBR region while detecting the oscillation wavelength of an output light of the semiconductor laser so as to detect a DBR current value I.sub.0 corresponding to a predetermined wavelength value, and then monotonously varies the DBR current in a second direction which is opposite the first direction beyond the detected value I.sub.

Abstract: A light generating apparatus includes: a submount; a semiconductor laser chip mounted on the surmount; 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. The apparatus includes a control section which monotonously varies, in a first direction, a DBR current to be input to the DBR region while detecting the oscillation wavelength of an output light of the semiconductor laser so as to detect a DBR current value I.sub.0 corresponding to a predetermined wavelength value, and then monotonously varies the DBR current in a second direction which is opposite the first direction beyond the detected value I.sub.

Abstract: A method for manufacturing a polarization inversion part on the substrate of a ferroelectric crystal that is suitable for the use as a light wavelength conversion element or the like. A deep polarization inversion part or a homogeneous polarization inversion part is formed by one or more of: reinverting polarization in a part of the polarization inversion part; inverting polarization while applying a voltage also in the perpendicular direction to the polarization direction of a crystal; forming a low resistance part between electrodes to which an voltage is applied; inverting polarization from a electrode formed in a concave part on the surface of a substrate; applying a high voltage utilizing a insulating film; or the like.

Abstract: An optical waveguide of the present invention includes: an optical material; an optical waveguide layer formed in the optical material; and a cladding layer formed on a surface of the optical waveguide layer, wherein the optical waveguide layer is capable of guiding a light beam having a wavelength of .lambda.1 and a light beam having a wavelength of .lambda.2 (.lambda.1>.lambda.2) therethrough, and a refractive index and a thickness of the cladding layer are determined so as to satisfy a guiding condition for the light beam having the wavelength of .lambda.2 and a cutoff condition for the light beam having the wavelength of .lambda.1.

Abstract: A light generating apparatus includes: a submount; a semiconductor laser chip mounted on the submount; a substrate which is mount 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. The apparatus includes a control section which monotonously varies, in a first direction, a DBR current to be input to the DBR region while detecting the oscillation wavelength of an output light of the semiconductor laser so as to detect a DBR current value I.sub.o corresponding to a predetermined wave-length value, and then monotonously varies the DBR current in a second direction which is opposite the first direction beyond the detected value I.sub.

Abstract: An excellent periodic domain-inverted structure formed on a ferroelectric optical single crystal substrate is provided having an improved crystalline property of the substrate and an improved resistance to optical damage and output of the domain-inverted structure and the like optical waveguide structure by forming protruded and recessed portions on a single-domained ferroelectric optical single crystal substrate 1, growing a film of a ferroelectric optical single crystal film 4 on the respective recessed portion of the single crystal substrate 1 by a liquid phase epitaxial growing process. At that time, the Curie temperature of the film 4 is lower than the liquid phase epitaxial growing temperature of the film 4, and the Curie temperature of the substrate 1 is higher than the liquid phase epitaxial growing temperature of the film 4, and the film 4 is polarized in an opposite direction to the polarization direction of the substrate 1.

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 LiTaO.sub.3 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 of the present invention includes: an optical material; an optical waveguide layer formed in the optical material; and a cladding layer formed on a surface of the optical waveguide layer, wherein the optical waveguide layer is capable of guiding a light beam having a wavelength of .lambda.1 and a light beam having a wavelength of .lambda.2 (.lambda.1>.lambda.2) therethrough, and a refractive index and a thickness of the cladding layer are determined so as to satisfy a guiding condition for the light beam having the wavelength of .lambda.2 and a cutoff condition for the light beam having the wavelength of .lambda.1.

Abstract: An optical wavelength converting device is provided with a LiTaO.sub.3 substrate, a plurality of inverted-polarization layers periodically arranged in an upper surface of the LiTaO.sub.3 substrate, and an optical waveguide crossing the inverted-polarization layers. The upper surface of the LiTaO.sub.3 substrate is directed toward a -X-crystal axis direction. The inverted-polarization layers are formed by exchanging Ta.sup.+ ions of the LiTaO.sub.3 substrate for H.sup.+ ions, and an extending direction of each inverted-polarization layer is inclined at an angle of .theta. degrees (6.ltoreq..theta..ltoreq.174) to the +C-crystal axis direction toward a -Y-crystal axis direction. The optical waveguide is formed by exchanging Ta.sup.+ ions of the LiTaO.sub.3 substrate and the inverted-polarization layers for H.sup.+ ions to set a refractive index of the optical waveguide higher than that of the LiTaO.sub.3 substrate. The optical waveguide extends in a +Y-crystal axis direction.

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. The apparatus includes a control section which monotonously varies, in a first direction, a DBR current to be input to the DBR region while detecting the oscillation wavelength of an output light of the semiconductor laser so as to detect a DBR current value I.sub.0 corresponding to a predetermined wavelength value, and then monotonously varies the DBR current in a second direction which is opposite the first direction beyond the detected value I.sub.

Abstract: A comb-shaped electrode and a planar electrode are formed on a surface and a bottom face of a substrate. Then, a DC voltage on which a pulse voltage is superimposed is applied to the electrodes using a DC power source and a pulse power source so as to apply a DC electric field on which a pulse electric field is superimposed to the substrate. As a result, periodic domain-inverted regions are formed by applying even a small pulse electric field. Since the applied electric field is highly uniform in a face of the substrate, the domain-inverted regions having a uniform periodic structure are formed. Alternatively, after the comb-shaped electrode is covered with an insulating film, the pulse voltage is applied to the electrodes using the pulse power source so as to apply the pulse electric field to the substrate.

Abstract: A diffracting device consists of a substrate made of LiTaO.sub.3, an optical waveguide extending in a central upper side of the substrate for transmitting 860 nm wavelength coherent light radiated from a semiconductor laser, a plurality of gratings periodically arranged on the optical waveguide at regular intervals, and a covering layer arranged on the gratings and the optical waveguide. The optical waveguide is formed according to a proton-exchange process. The gratings are made of photoresist material having a refractive index N1=1.5 and a high workability, and the gratings are uniformly formed according to an interference-exposure process. Therefore, the photoresist material is patterned without damaging the optical waveguide with reactive ions. The covering layer is made of Ta.sub.2 O.sub.5 having a refractive index N2=2.0.

Abstract: A frequency doubler comprising periodic domain-inverted regions, in which a nonlinear degradation layer is formed on the surface of a waveguide, whereby the TM.sub.00 mode of the fundamental wave is converted into the TM.sub.10 mode of the high harmonic wave so as to reduce the effects of optical damage in order to stably output the TM.sub.10 mode of the high harmonic wave.

Abstract: An optical wavelength converting device is provided with a LiTaO.sub.3 substrate, a plurality of inverted-polarization layers periodically arranged in an upper surface of the LiTaO.sub.3 substrate, and an optical waveguide crossing the inverted-polarization layers. The upper surface of the LiTaO.sub.3 substrate is directed toward a -X-crystal axis direction. The inverted-polarization layers are formed by exchanging Ta.sup.+ ions of the LiTaO.sub.3 substrate for H.sup.+ ions, and an extending direction of each inverted-polarization layer is inclined at an angle of .theta. degrees (6.ltoreq..theta..ltoreq.174) to the +C-crystal axis direction toward a -Y-crystal axis direction. The optical waveguide is formed by exchanging Ta.sup.+ ions of the LiTaO.sub.3 substrate and the inverted-polarization layers for H.sup.+ ions to set a refractive index of the optical waveguide higher than that of the LiTaO.sub.3 substrate. The optical waveguide extends in a +Y-crystal axis direction.