Abstract: An optical fiber guide that guides an optical fiber, the optical fiber guide includes a first substrate, and a guide groove that is formed on a main surface of the first substrate, the optical fiber being insertable from one end side of the guide groove, wherein the guide groove includes a positioning unit that forms a distal end portion of the guide groove, the positioning unit having a slide inclined surface that positions the optical fiber by sliding a distal-end inclined surface of the optical fiber in contact therewith.

Abstract: A semiconductor device where an outside connection terminal of a semiconductor element and an electrode of a wiring board are connected to each other via a conductive adhesive, the conductive adhesive includes a first conductive adhesive; and a second conductive adhesive covering the first conductive adhesive; wherein the first conductive adhesive contains a conductive filler including silver (Ag); and the second conductive adhesive contains a conductive filler including a metal selected from a group consisting of tin (Sn), zinc (Zn), cobalt (Co), iron (Fe), palladium (Pd), and platinum (Pt).

Abstract: A semiconductor device where an outside connection terminal of a semiconductor element and an electrode of a wiring board are connected to each other via a conductive adhesive, the conductive adhesive includes a first conductive adhesive; and a second conductive adhesive covering the first conductive adhesive; wherein the first conductive adhesive contains a conductive filler including silver (Ag); and the second conductive adhesive contains a conductive filler including a metal selected from a group consisting of tin (Sn), zinc (Zn), cobalt (Co), iron (Fe), palladium (Pd), and platinum (Pt).

Abstract: A semiconductor device where an outside connection terminal of a semiconductor element and an electrode of a wiring board are connected to each other via a conductive adhesive, the conductive adhesive includes a first conductive adhesive; and a second conductive adhesive covering the first conductive adhesive; wherein the first conductive adhesive contains a conductive filler including silver (Ag); and the second conductive adhesive contains a conductive filler including a metal selected from a group consisting of tin (Sn), zinc (Zn), cobalt (Co), iron (Fe), palladium (Pd), and platinum (Pt).

Abstract: Disclosed is an optical waveguide structure capable of keeping intervals between the structure and optical elements within a certain range. When arranging a surface light emitting element and a surface light receiving element on a positioning plate provided on a substrate, elastic layers are provided between the elements and the plate. When fitting and fixing first projections of the structure in holes of the plate, second projections formed in a predetermined dimension on the structure are brought into contact with the light emitting element and the light receiving element. Therefore, intervals between lenses, and the light emitting element as well as the light receiving element are controlled within a certain range according to the dimension of the second projections. Further, stress occurring due to contact is dispersed by the elastic layers so that breakage of the light emitting element and the light receiving element can be prevented.

Abstract: A semiconductor device where an outside connection terminal of a semiconductor element and an electrode of a wiring board are connected to each other via a conductive adhesive, the conductive adhesive includes a first conductive adhesive; and a second conductive adhesive covering the first conductive adhesive; wherein the first conductive adhesive contains a conductive filler including silver (Ag); and the second conductive adhesive contains a conductive filler including a metal selected from a group consisting of tin (Sn), zinc (Zn), cobalt (Co), iron (Fe), palladium (Pd), and platinum (Pt).

Abstract: An optical waveguide structure capable of optically coupling a surface type optical device, such as a surface emitting laser diode or a photodiode, and a transmission medium, such as an optical fiber, located so that their light output surface and light input surface will form an angle of about 90° with each other simply and easily. The optical waveguide structure comprises a first clad section having a curved surface for gradually turning the direction in which light travels almost squarely and a groove formed in the curved surface along the direction in which light travels, a core section which is made from a transparent material with a refractive index higher than the refractive index of the first clad section and with which the groove is filled in, and a second clad section which covers an exposed surface of the core section and the curved surface of the first clad section and which is integrated with the first clad section.

Abstract: Disclosed is an optical waveguide structure capable of keeping intervals between the structure and optical elements within a certain range. When arranging a surface light emitting element and a surface light receiving element on a positioning plate provided on a substrate, elastic layers are provided between the elements and the plate. When fitting and fixing first projections of the structure in holes of the plate, second projections formed in a predetermined dimension on the structure are brought into contact with the light emitting element and the light receiving element. Therefore, intervals between lenses, and the light emitting element as well as the light receiving element are controlled within a certain range according to the dimension of the second projections. Further, stress occurring due to contact is dispersed by the elastic layers so that breakage of the light emitting element and the light receiving element can be prevented.

Abstract: The optical deflector comprises: an optical waveguide 12 of a dielectric material having electrooptical effect; and a pair of electrodes 10, 14 opposed to each other across the optical waveguide, an electric field is applied between the opposed electrodes to change a refractive index of the dielectric material to thereby control a propagating direction of signal light propagating in the optical waveguide 12, wherein the dielectric material has a first refractive index in its initial state, has a second refractive index by application of an electric field of a first polarity, and retains as a third refractive index a refractive index obtained after the electric field has been removed. The dielectric material has the third refractive index has the first refractive index by the application of an electric field of a second polarity different from the first polarity and removal of the electric field.

Abstract: The optical deflector comprises: an optical waveguide 12 of a dielectric material having electrooptical effect; and a pair of electrodes 10, 14 opposed to each other across the optical waveguide, an electric field is applied between the opposed electrodes to change a refractive index of the dielectric material to thereby control a propagating direction of signal light propagating in the optical waveguide 12, wherein the dielectric material has a first refractive index in its initial state, has a second refractive index by application of an electric field of a first polarity, and retains as a third refractive index a refractive index obtained after the electric field has been removed. The dielectric material has the third refractive index has the first refractive index by the application of an electric field of a second polarity different from the first polarity and removal of the electric field.

Abstract: An optical deflector including an optical waveguide of a dielectric material having electrooptical effect; and a pair of electrodes opposed to each other across the optical waveguide. An electric field is applied between the opposed electrodes to change a refractive index of the dielectric material to thereby control a propagating direction of signal light propagating in the optical waveguide, wherein the dielectric material has a first refractive index in its initial state, has a second refractive index by application of an electric field of a first polarity, and retains as a third refractive index a refractive index obtained after the electric field has been removed. The dielectric material having the third refractive index has the first refractive index by the application of an electric field of a second polarity different from the first polarity and removal of the electric field.

Abstract: An optical waveguide comprising an MgO substrate 10, and a slab waveguide layer 24 formed on the MgO substrate 10 and including a core layer 18 of a ferroelectric or an antiferroelectric, further comprises a stress alleviating layer 12 which substantially lattice-matches with the MgO substrate and the slab waveguide layer 24 and has an average thermal expansion coefficient in the range of 7.0×10?6-14.0×10?6/° C. at the room temperature to 700° C. Accordingly, the optical waveguide device utilizing the magnesium oxide substrate can be formed without breaking the optical waveguide layer and the magnesium oxide substrate itself.

Abstract: An optical waveguide structure capable of optically coupling a surface type optical device, such as a surface emitting laser diode or a photodiode, and a transmission medium, such as an optical fiber, located so that their light output surface and light input surface will form an angle of about 90° with each other simply and easily. The optical waveguide structure comprises a first clad section having a curved surface for gradually turning the direction in which light travels almost squarely and a groove formed in the curved surface along the direction in which light travels, a core section which is made from a transparent material with a refractive index higher than the refractive index of the first clad section and with which the groove is filled in, and a second clad section which covers an exposed surface of the core section and the curved surface of the first clad section and which is integrated with the first clad section.

Abstract: A piezoelectric actuator includes a single-crystal piezoelectric thin film having a crystal orientation aligned with the crystal orientation of a single-crystal Si substrate, and first and second electrode films formed on first and second sides of the single-crystal piezoelectric thin film, respectively.

Abstract: A piezoelectric actuator includes a single-crystal piezoelectric thin film having a crystal orientation aligned with the crystal orientation of a single-crystal Si substrate, and first and second electrode films formed on first and second sides of the single-crystal piezoelectric thin film, respectively.

Abstract: An optical waveguide comprising an MgO substrate 10, and a slab waveguide layer 24 formed on the MgO substrate 10 and including a core layer 18 of a ferroelectric or an antiferroelectric, further comprises a stress alleviating layer 12 which substantially lattice-matches with the MgO substrate and the slab waveguide layer 24 and has an average thermal expansion coefficient in the range of 7.0×10−6-14.0×10−6/° C. at the room temperature to 700° C. Accordingly, the optical waveguide device utilizing the magnesium oxide substrate can be formed without breaking the optical waveguide layer and the magnesium oxide substrate itself.

Abstract: The optical deflector comprises: an optical waveguide 12 of a dielectric material having electrooptical effect; and a pair of electrodes 10, 14 opposed to each other across the optical waveguide, an electric field is applied between the opposed electrodes to change a refractive index of the dielectric material to thereby control a propagating direction of signal light propagating in the optical waveguide 12, wherein the dielectric material has a first refractive index in its initial state, has a second refractive index by application of an electric field of a first polarity, and retains as a third refractive index a refractive index obtained after the electric field has been removed. The dielectric material has the third refractive index has the first refractive index by the application of an electric field of a second polarity different from the first polarity and removal of the electric field.

Abstract: A prism pair is employed as an optical deflecting element. The prism pair is constructed by a slab waveguide, and first and second upper electrodes and first and second lower electrodes arranged on and under the slab waveguide. These electrodes are shaped into a wedge shape (e.g., triangular shape), and change the refractive index of a part of the slab waveguide by utilizing the electrooptic effect to change the propagation direction of light.

Abstract: A prism pair is employed as an optical deflecting element. The prism pair is constructed by a slab waveguide, and first and second upper electrodes and first and second lower electrodes arranged on and under the slab waveguide. These electrodes are shaped into a wedge shape (e.g., triangular shape), and change the refractive index of a part of the slab waveguide by utilizing the electrooptic effect to change the propagation direction of light.

Abstract: In a method of manufacturing piezoelectric ceramics by molding pre-fired or calcined powders of ingredients of a piezoelectric ceramic material and sintering the powder mold at a high pressure, the powder mold is pre-sintered at an atmospheric pressure before sintering at high pressure (HIP). Preferably, after the sintering HIP step, a thermal treatment is performed at a temperature of from 500 to 1000.degree. C. under an oxidizing atmosphere. For a Pb(Zn.sub.1/3 Nb.sub.2/3)O.sub.3 --PbTiO.sub.3 based piezoelectric ceramic, the composition is preferably set to (Pb.sub.1-x Ba.sub.x)[(Zn.sub.1/3 Nb.sub.2/3).sub.1-y Ti.sub.y ]O.sub.3, where 0.001<x<0.055 and 0.05<y<0.20.