Abstract: A light wavelength converter which includes a light source for emitting fundamental waves having a desired wavelength, a first loop-shaped optical waveguide for converting the fundemental waves into harmonics, and a second optical waveguide for receiving the light from the source, wherein the two waveguides are coupled by an optical directional coupler.

Abstract: A method for producing a diffraction grating in optical elements with an optical waveguide is disclosed which comprises the steps of: forming a transparent conductive film on the optical waveguide; forming an electron beam resist film on said transparent conductive film; drawing a diffraction grating pattern on said resist film with an electron beam; and developing said resist film with a diffraction grating pattern drawn thereon to form a resist film of the diffraction grating pattern.

Abstract: A light wavelength converter comprising a substrate that is made of a material with a non-linear optical effect, and a loop-shaped optical waveguide that is formed on the substrate, whereby a second harmonic wave or a sum wave emanates from a fundamental wave that has been propagated in a specific area of the optical waveguide and part of the fundamental wave that has not been converted to the second harmonic wave or the sum wave is returned to the specific area of the optical waveguide, so that a fundamental wave with a relatively low output can be efficiently converted to a second harmonic wave and a high-output second harmonic wave can be obtained.

Abstract: A grating coupler comprising an optical waveguide and a grating formed on the optical waveguide in which light is propagated for optically coupled light rays inside and outside of the optical waveguide, wherein the coupling coefficient of the grating coupler is gradually changed in the direction of propagation of guided light in the optical waveguide, whereby the intensity distribution of light rays inside or outside of the optical waveguide agrees with the coupling efficiency distribution of the grating coupler, so the coupling efficiency of the grating coupler can be greatly improved.

Abstract: Disclosed is an optical pumping-type solid-state laser apparatus in which a semiconductor laser device is used as a light source for optical pumping. The solid-state laser apparatus includes first and second photodetectors. The former detects the amount of light emitted from the semiconductor laser device, and the latter detects the amount of laser light transmitted through a filter plate which has the same light-absorbance characteristics as that of the solid-state laser. In accordance with the detected results, a driving circuit drives the semiconductor laser device to obtain a laser beam with an appropriate output level and a temperature regulator regulates the temperature of the semiconductor laser device so that the wavelength of the laser light to be emitted therefrom is accurately adjusted to be the same as that of the light to be efficiently absorbed by the solid-state laser. The laser beam with the accurately adjusted wavelength is used for optically pumping the solid-state laser.

Abstract: An image processing device for controlling data transfer includes an image scanner, an image printer, a facsimile control unit, bus lines for data transfer, a bidirectional parallel interface unit, and a main CPU in a housing. The device is connected to an external data processing device through the parallel interface unit. In addition to the functions which are obtained independent from the external data processing device, the image processing device realizes various kinds of functions by controlling the image scanner, the image printer facsimile control unit and the interface unit by the main CPU in response to commands from the data processing device. As a result, various kinds of image processing functions are carried out.

Abstract: A light wavelength converter comprising a substrate that is made of a material attaining a non-linear effect; an optical waveguide that is formed within said substrate; a light source that irradiates said optical waveguide with a pair of lights having a fundamental waveguide, said pair of lights being propagated within said optical waveguide and intersecting each other within said optical waveguide to thereby generate a second harmonic light; and a light deflection means that changes the intersection angle between the pair of waveguiding lights based on an electric signal that is input into said light deflection means, whereby, the phase matching condition of a pair of incident laser beams can be readily satisfied and, even when the ambient temperature changes, the second harmonic light can be stably generated.

Abstract: A method for the formation of a diffraction grating on a substrate using a holographic technique and an etching technique, wherein the periodicity of the pattern of the diffraction grating can be changed at will by a change of the light-path length of one of the two light fluxes from a holographic exposing system.

Abstract: The present invention provides a solid electrolyte type of fuel cell of a planar type structure comprising a plurality of solid electrolyte plates, each being in the form of a flat plate and having a porous cathodic layer on one side and a porous anodic layer on the other side, which are laminated together through an interconnector plate provided in both its sides with grooves defining gas passages, wherein oxidizing agent and fuel gases are fed through said passages to the cathodic and anodic sides, thereby reducing the length of a current path running through regions of high resistance, increasing the degree of integration and improving reliability. By using heat-resistant parts for the interconnectors, cathodes and anodes, it is also possible to improve the resistance to oxidation and reduction as well as durability and obtain low resistance.

Abstract: An optical information processing apparatus including a substrate of a transparent material, first and second optical waveguides formed on opposite faces of said transparent substrate, a light introducing device for introducing reflected light from an information writing medium into the first and second optical waveguides, and a detecting device for detecting reproduction signal, tracking error signal and focusing error signal based on the reflected light introduced into the first and second optical waveguides.

Abstract: A semiconductor laser element of the present invention provides a double hetero junction structure having two clad layers and an active layer formed between the two clad layers. High resistance regions are formed vertically to the light propagating direction at almost the same interval as the light wavelength in at least one of the two clad layers. The high resistance regions form a periodic current blocking structure so the semiconductor laser element may oscillate in a single longitudinal mode even in a non-steady state operation.

Abstract: A semiconductor device formed in a semiconductor substrate and having a gate electrode formed on the semiconductor substrate, source and drain regions are formed in said the semiconductor substrate. The source and drain regions are made of a first impurity region doped with impurities of an opposite conductivity type to that of a semiconductor substrate formed at portions adjacent to the edge of the gate electrode, a second impurity region doped with impurities of an opposite conductivity type to that of a semiconductor substrate formed at portions under the first impurity region, and a third impurity region doped with impurities of opposite conductivity type to that of a semiconductor substrate formed at portions spaced apart from the edge of the gate electrode. The impurities of the second impurity region have a diffusion coefficient larger than that of the impurities of the first impurity region.

Abstract: An image processing device for controlling data transfer includes an image scanner, an image printer, a facsimile control unit, bus lines for data transfer, a bidirectional parallel interface unit, and a main CPU in a housing. The device is connected to an external data processing device through the parallel interface unit. In addition to the functions which are obtained independent from the external data processing device, the image processing device realizes various kinds of functions by controlling the image scanner, the image printer facsimile control unit and the interface unit by the main CPU in response to commands from the data processing device. As a result, various kinds of image processing functions are carried out.

Abstract: A semiconductor laser device comprising a semiconductor substrate, an active layer having a refractive index greater than that of said substrate and having an energy gap smaller than that of said substrate, and a cladding layer having a conductivity type different from that of said substrate, in that order, resulting in a double-heterostructure, wherein two parallel grooves with a given distance therebetween are disposed in the double-heterostructure so as to reach said substrate and a first burying layer having the same conductivity type as said substrate, a second burying layer having a conductivity type different from that of said substrate and a third burying layer having the same conductivity type as said substrate are disposed outside of the two grooves in that order, and moreover a semiconductor layer with the flat surface having a conductivity type different from that of said substrate is disposed over the third burying layer and the area positioned between the two parallel grooves.

Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operation area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.

Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operating area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.

Abstract: An integrated semiconductor laser device comprising a plurality of semiconductor laser device elements, at least one of which has a means for preventing the injection of current in the vicinity of one facet or both facets.

Abstract: A vapor phase synthesis of carbon film and carbon particles using a single or a mixed gas capable of supplying halogen, hydrogen and carbon atoms is disclosed. Halogen radicals can suppress the desorption of carbon atoms from the substrate, and the carbon layer is obtained easily. Especially chlorine and fluorine atoms are effective. An electron beam diffraction pattern illustrated that diamond film can be obtained in this method.

Abstract: A semiconductor laser device comprising a double-heterostructure that is composed of an active layer and a pair of cladding layers sandwiching the active layer therebetween, and a stripe structure that is disposed on the double-heterostructure, the stripe structure being composed of a current blocking layer with a conductive type different from that of the adjacent cladding layer, and the current blocking layer having a striped groove constituting a current path, wherein the cladding layer that contacts the current blocking layer is composed of an In.sub.1-s Ga.sub.s P.sub.1-t As.sub.t crystal material (wherein 0.51.ltoreq.s.ltoreq.1, 0.ltoreq.t.ltoreq.1 and s=2.04t-1.04).

Abstract: A device for the changing of the wavelength of light comprising a non-linear optical crystal, first and second optical waveguides that are formed in the non-linear optical crystal, and an introducing means that is positioned adjacent to the second optical waveguide, the light being incident upon the first optical waveguide and propagated within the first optical waveguide, resulting in harmonic light that satisfies the phase-matching conditions, and the harmonic light being introduced, by the introducing means, into the second optical waveguide from which the harmonic light is output.