Abstract: A crucible comprising Al2O3 and at least one selected from rare earth oxides inclusive of Y2O3 as main components and characterized by firing at 500–1,800° C., the distribution of the rare earth oxide at a higher proportion in a fine particle portion having a particle size of up to 0.5 mm than in a coarse particle portion having a particle size in excess of 0.5 mm, and the substantial absence of the reaction product of the rare earth oxide with Al2O3 is suitable for the melting of a rare earth alloy.

Abstract: A glass substrate is irradiated with a converged laser beam to thereby form a spherical or nearly spherical convex portion on a surface of the glass substrate. More preferably, there may be used a method including the steps of: sticking a glass substrate to a flat member having a predetermined spherical or aspherical concave portion formed therein; and irradiating a converged laser beam onto a surface of the glass substrate just under the concave portion while making the converged laser beam penetrate through the flat member to thereby form a spherical or aspherical convex portion in the inside of the concave portion in accordance with the shape of the concave portion.

Abstract: A lens-attached light-emitting element for increasing an optical availability efficiency is provided. A lens-attached light-emitting element for structuring a light-emitting element array arranged in one dimension comprises a light-emitting element having an approximately U-shaped light-emitting area; and an approximately U-shaped composite lens including a combination of two cylindrical lenses arranged in a direction of the one dimension, one cylindrical lens, and four hemispherical lenses. Where the width in a direction of the one dimension of the light-emitting area is p, the thickness of the base portion of the composite lens is in the range of 0–0.71 p, a radius of curvature of each of the cylindrical lens and hemispherical lens is in the range of 0.20 p–0.47 p, and a center-to-center distance between at least two cylindrical lenses is in the range of 0.35 p–0.89 p.

Abstract: A crucible comprising Al2O3 and at least one selected from rare earth oxides inclusive of Y2O3 as main components and characterized by firing at 500-1,800° C., the distribution of the rare earth oxide at a higher proportion in a fine particle portion having a particle size of up to 0.5 mm than in a coarse particle portion having a particle size in excess of 0.5 mm, and the substantial absence of the reaction product of the rare earth oxide with Al2O3 is suitable for the melting of a rare earth alloy.

Abstract: A rare-earth alloy ingot is produced by melting an alloy composed of 20-30 wt % of a rare-earth constituent which is Sm alone or at least 50 wt % Sm in combination with at least one other rare-earth element, 10-45 wt % of Fe, 1-10 wt % of Cu and 0.5-5 wt % of Zr, with the balance being Co, and quenching the molten alloy in a strip casting process. The strip-cast alloy ingot has a content of 1-200 ?m size equiaxed crystal grains of at least 20 vol % and a thickness of 0.05-3 mm. Rare-earth sintered magnets made from such alloys exhibit excellent magnetic properties and can be manufactured under a broad optimal temperature range during sintering and solution treatment.

Abstract: A stereoimage formation apparatus includes two lens array plates, each of which includes microlenses having optical axes and peaks. The optical axes of the microlenses are parallel to one another. The optical axes of the microlenses in one of the lens array plates are aligned with the optical axes of the microlenses in the other lens array plate. The peaks of the microlenses in one of the lens array plates come in contact with or are located proximal to the peaks of the microlenses in the other lens array plate. The microlenses of each lens array plate each have a predetermined spherical aberration greater than a predetermined minimum spherical aberration.

Abstract: A semiconductor laser element comprising: a clad layer of a first conductivity type; an active layer; a first clad layer of a second conductivity type; a ridge made of a second clad layer of the second conductivity type and a cap layer of the second conductivity type, which are layered on the first clad layer of the second conductivity type, in this order starting from the first clad layer side; a dielectric film formed on ridge sides other than a top portion of the ridge; and a metal electrode layer that covers the ridge, wherein the width of the bottom of the cap layer and the width of the top surface of the second clad layer are approximately equal.

Abstract: An optical module includes at least one optical fiber, a gradient index rod lens, and an optical element. The rod lens is placed at a position separated from an end surface of the optical fiber by a space. The optical element is separated from the rod lens. Outgoing light from the single optical fiber is inputted to the optical element via the rod lens, and light reflected by the optical element is coupled to the optical fiber via the rod lens. When a distance between the rod lens and the optical element is longer than a predetermined value, and a lens length optimized for the distance is equal to or less than a predetermined pitch, the rod lens has end surfaces perpendicular to an optical axis.

Abstract: A lens-attached light-emitting element for increasing an optical availability efficiency is provided. A lens-attached light-emitting element for structuring a light-emitting element array arranged in one dimension comprises a light-emitting element having an approximately U-shaped light-emitting area; and an approximately U-shaped composite lens including a combination of two cylindrical lenses arranged in a direction of the one dimension, one cylindrical lens, and four hemispherical lenses. Where the width in a direction of the one dimension of the light-emitting area is p, the thickness of the base portion of the composite lens is in the range of 0-0.71 p, a radius of curvature of each of the cylindrical lens and hemispherical lens is in the range of 0.20 p-0.47 p, and a center-to-center distance between at least two cylindrical lenses is in the range of 0.35 p-0.89 p.

Abstract: Provided is a semiconductor laser element depositing an insulating film on a p-type cladding layer in which it is possible to prevent bulk deterioration of the semiconductor laser element by suppressing thermal stress caused on a p-type cladding layer. A compound semiconductor multilayer structure is formed by depositing an n-type cladding layer, an active layer and a p-type cladding layer having a ridge part formed thereon sequentially in a deposition direction. Then, deposited in the deposition direction of the compound semiconductor structure is an insulating film formed of an insulating material which has a refractive index different from that of a material constituting the p-type cladding layer and a thermal expansion coefficient approximate to that of a material constituting the p-type cladding layer.

Abstract: A semiconductor laser element comprising: a clad layer of a first conductivity type; an active layer; a first clad layer of a second conductivity type; a ridge made of a second clad layer of the second conductivity type and a cap layer of the second conductivity type, which are layered on the first clad layer of the second conductivity type, in this order starting from the first clad layer side; a dielectric film formed on ridge sides other than a top portion of the ridge; and a metal electrode layer that covers the ridge, wherein the width of the bottom of the cap layer and the width of the top surface of the second clad layer are approximately equal.

Abstract: A semiconductor laser device has a ridge portion composed of a cladding layer and a cap layer laid on top of the cladding layer, and a filling layer formed on opposite lateral sides of the ridge portion. A top surface of the cap layer and a top surface of the filling layer meet at an angle of 135° or larger but not larger than 180° on an upper side of the cap layer. In manufacturing the device, after a filling layer is formed so as to cover the ridge portion, an insulating film is formed and a portion above the ridge portion is selectively removed from the insulating film to expose the filling layer. Then, the exposed filling layer is removed till a top surface of the ridge portion is exposed.

Abstract: There is provided a semiconductor laser device which is generally uniform in carrier concentration of a clad layer, almost free from strain, and less demanding for time and labor in its manufacturing, and which has stable characteristics. On an n-GaAs substrate, an n-type clad layer, an active layer, a p-type clad layer, and a cap layer are stacked one on another at a temperature of 700-750° C. Widthwise both side portions of the cap layer as well as widthwise both side specified-depth portions of the p-type clad layer are removed by etching to form a ridge portion, and a current constriction layer is formed on widthwise both sides of the ridge portion. A flattening layer having a planar surface is formed on the current constriction layer and the cap layer by slow cooling LPE process at a temperature of 700° C. or lower. On the flattening layer, a contact layer is formed by MOCVD process at a temperature of about 650° C.

Abstract: A crucible comprising Al2O3 and at least one selected from rare earth oxides inclusive of Y2O3 as main components and characterized by firing at 500-1,800° C., the distribution of the rare earth oxide at a higher proportion in a fine particle portion having a particle size of-up to 0.5 mm than in a coarse particle portion having a particle size in excess of 0.5 mm, and the substantial absence of the reaction product of the rare earth oxide with Al2O3 is suitable for the melting of a rare earth alloy.

Abstract: An alloy powder for bonded rare earth magnets is prepared by melting an alloy consisting essentially of 20-30 wt % of Sm or a mixture of rare earth elements (inclusive of Y) containing at least 50 wt % of Sm, 10-45 wt % of Fe, 1-10 wt % of Cu, 0.5-5 wt % of Zr, and the balance of Co, quenching the melt by a strip casting technique, to form a rare earth alloy strip containing at least 20% by volume of equiaxed crystals with a grain size of 1-200 &mgr;m and having a gage of 0.05-3 mm, and heat treating the strip in a non-oxidizing atmosphere at 1000-1300° C. for 0.5-20 hours, followed by aging treatment and grinding.

Abstract: A rare-earth alloy ingot is produced by melting an alloy composed of 20-30 wt % of a rare-earth constituent which is Sm alone or at least 50 wt % Sm in combination with at least one other rare-earth element, 10-45 wt % of Fe, 1-10 wt % of Cu and 0.5-5 wt % of Zr, with the balance being Co, and quenching the molten alloy in a strip casting process. The strip-cast alloy ingot has a content of 1-200 &mgr;m size equiaxed crystal grains of at least 20 vol % and a thickness of 0.05-3 mm. Rare-earth sintered magnets made from such alloys exhibit excellent magnetic properties and can be manufactured under a broad optimal temperature range during sintering and solution treatment.

Abstract: An optical module includes at least one optical fiber, a gradient index rod lens, and an optical element. The rod lens is placed at a position separated from an end surface of the optical fiber by a space. The optical element is separated from the rod lens. Outgoing light from the single optical fiber is inputted to the optical element via the rod lens, and light reflected by the optical element is coupled to the optical fiber via the rod lens. When a distance between the rod lens and the optical element is longer than a predetermined value, and a lens length optimized for the distance is equal to or less than a predetermined pitch, the rod lens has end surfaces perpendicular to an optical axis.

Abstract: Distribution of machining ability in periphery surface is grasped and evaluated through measuring the machined depth at several positions of the peripheral portion by use of a wafer for the evaluation of the ability of machining the peripheral portion thereof.

Abstract: A glass substrate is irradiated with a converged laser beam to thereby form a spherical or nearly spherical convex portion on a surface of the glass substrate. More preferably, there may be used a method including the steps of: sticking a glass substrate to a flat member having a predetermined spherical or aspherical concave portion formed therein; and irradiating a converged laser beam onto a surface of the glass substrate just under the concave portion while making the converged laser beam penetrate through the flat member to thereby form a spherical or aspherical convex portion in the inside of the concave portion in accordance with the shape of the concave portion.

Abstract: A method for producing an aspherical structure according to the invention includes the steps of: forming a layer on a surface of a substrate so that the layer exhibits an etching rate distribution in a direction perpendicular to the surface of the substrate; forming a mask having a predetermined opening shape on the surface of the layer; and etching the layer to thereby form at least one aspherical concave portion. When each concave portion is used as a molding tool so that a resin with which the concave portion is filled is solidified and removed from the concave portions an aspherical lens array can be formed accurately.