Abstract: An optical component having an NA conversion function which enables arraying without lowering a product yield, with small size and a simple assembly process. There is provided an optical component using a capillary type lens array in which plural graded index lenses each of which is surrounded with glass capillary in all circumferential directions, in which a refractive index distribution constant of the plurality of graded index lenses at one end of the optical component in an optical axis direction of the graded index lens is smaller than a refractive index distribution constant of the plurality of graded index lenses at other end of the optical component in the optical axis direction of the graded index lens.

Abstract: An optical combiner using a graded index lens that emits light incident on an incident end surface from an emission end surface, the optical combiner including partial regions having different distances from the emission end surface of the graded index lens, on the incident end surface of the graded index lens, in which wavelengths of lights focused on an optical axis of the emission end surface are determined in advance for the respective partial regions.

Abstract: A capillary-type lens array having an inorganic glass around a graded index lens, in which a plurality of the graded index lenses and the inorganic glass are physically fused.

Abstract: An optical connection apparatus comprising a prism that extracts N×M beams of outgoing light from an optical circuit, a two-dimensional GRIN lens array of N×M GRIN lenses, a spacer, having a thickness according to the optical path length in the prism, that transmits N×M outgoing beams from the two-dimensional GRIN lens array, and a two-dimensional fiber array that causes the N×M beams to be incident on optical fibers, the ends of optical fibers being disposed at the focal point of each of the beams transmitted through the spacer.

Abstract: A capillary-type lens array having an inorganic glass around a graded index lens, in which a plurality of the graded index lenses and the inorganic glass are physically fused.

Abstract: A perforated quartz glass tube includes a jacket tube containing a quartz glass material, a plurality of cylindrical glass tubes which are inserted into a pore region of the jacket tube along an axial direction of the jacket tube, and contain a quartz glass material having a softening point higher than a softening point of the jacket tube, and a gap member which is inserted into a gap between the cylindrical glass tubes and a gap between the jacket tube and the cylindrical glass tube, and contains a quartz glass material having a softening point lower than a softening point of the cylindrical glass tube.

Abstract: An optical component having an NA conversion function which enables arraying without lowering a product yield, with small size and a simple assembly process. There is provided an optical component using a capillary type lens array in which plural graded index lenses each of which is surrounded with glass capillary in all circumferential directions, in which a refractive index distribution constant of the plurality of graded index lenses at one end of the optical component in an optical axis direction of the graded index lens is smaller than a refractive index distribution constant of the plurality of graded index lenses at other end of the optical component in the optical axis direction of the graded index lens.

Abstract: An optical connection apparatus comprising a prism that extracts N×M beams of outgoing light from an optical circuit, a two-dimensional GRIN lens array of N×M GRIN lenses, a spacer, having a thickness according to the optical path length in the prism, that transmits N×M outgoing beams from the two-dimensional GRIN lens array, and a two-dimensional fiber array that causes the N×M beams to be incident on optical fibers, the ends of optical fibers being disposed at the focal point of each of the beams transmitted through the spacer.

Abstract: A first disclosure is an optical fiber member equipped with two holding members that hold an optical fiber such that an end surface of the optical fiber is located on one end and a curving portion having a coat of the optical fiber is curved to be extended at another end; the holding members are provided with holding flat portions that sandwich an end portion of the optical fiber where the coat is removed such that the end surface of the optical fiber is located on the one end; at least any of the holding flat portions has an aligning groove to fix a position of the end portion of the optical fiber; the holding member is provided with a curved surface at a position adjacent to the curving portion in the extending direction D1; and the two holding members are equal in thermal expansion coefficient.

Abstract: A first disclosure is an optical fiber member equipped with two holding members that hold an optical fiber such that an end surface of the optical fiber is located on one end and a curving portion having a coat of the optical fiber is curved to be extended at another end; the holding members are provided with holding flat portions that sandwich an end portion of the optical fiber where the coat is removed such that the end surface of the optical fiber is located on the one end; at least any of the holding flat portions has an aligning groove to fix a position of the end portion of the optical fiber; the holding member is provided with a curved surface at a position adjacent to the curving portion in the extending direction Dl; and the two holding members are equal in thermal expansion coefficient.

Abstract: A device that enables highly efficient optical coupling between an end face of an optical circuit and an optical fiber without using a V-groove substrate. An optical coupling device that includes an optical fiber, a high NA optical waveguide, a mode field conversion portion having a mode field diameter larger than that of an opposite end of the high NA optical waveguide, and a capillary having a through-hole for holding the high NA optical waveguide and the mode field conversion portion, wherein the opposite end of the high NA optical waveguide is placed in the end portion of the through-hole.

Abstract: An optical coupling device that exhibits high air tightness between a capillary and an optical fiber formed of the same glass material. An optical coupling device according to this disclosure includes: an optical fiber having an end portion being a bare fiber where a part of coating has been removed, metal plating being applied to the bare fiber around an end portion of the remaining coating and a circumference of the coating; a capillary having a through-hole having one end where the end portion of the bare fiber is positioned and the other end where the end portion of the coating of the optical fiber subjected to the metal plating is placed, metal plating being applied to an inner wall surface of the other end of the through-hole; and solder that seals a gap between the optical fiber 11 placed in the other end of the through-hole and an inner wall of the through-hole.

Abstract: A perforated quartz glass tube includes a jacket tube containing a quartz glass material, a plurality of cylindrical glass tubes which are inserted into a pore region of the jacket tube along an axial direction of the jacket tube, and contain a quartz glass material having a softening point higher than a softening point of the jacket tube, and a gap member which is inserted into a gap between the cylindrical glass tubes and a gap between the jacket tube and the cylindrical glass tube, and contains a quartz glass material having a softening point lower than a softening point of the cylindrical glass tube.

Abstract: In a light waveguide circuit including a plurality of waveguides having different length, a material (10) having a temperature coefficient of a refractive index including a symbol different from that of a temperature coefficient of an effective refractive index of the waveguide (4) is charged into a groove (12) formed by removing the upper clad and the core from the waveguide (4), or a groove (12) formed by removing the upper clad, the core and the lower clad from the waveguide (4). A difference in length of the removed portions between adjacent waveguides is proportional to a difference in length of the waveguides which were not removed and remained.

Abstract: A method for producing a glass preform for an optical fiber comprising forming a fine glass particle mass by flame hydrolysis of a glass raw material, dehydrating the fine glass particle mass in an oxygen atmosphere containing chlorine or a chlorine-containing compound at such temperature that the soot preform is not considerably shrunk and heating the soot preform at a temperature at which the soot preform is sintered and made transparent, the glass preform produced by which method contains less hydroxyl groups, structural defects and an optical fiber fabricated from said glass preform has stable light transmission characteristics for a long time.

Abstract: A method for producing a glass preform for optical fibers in which fluorine is efficiently incorporated into the preform without incorporation of Fe or Cu. A fine glass particle mass, made primarily of quartz, is converted into transparent glass by heating it in a gas atmosphere containing at least a fluorine-based compound gas and a chlorine-based compound gas. The preferred heating range is 1,100.degree. to 1,400.degree. C.

Abstract: A quartz optical fiber comprising a core having a higher refractive index and made of pure quartz containing fluorine and phosphorus pentoxide and a cladding having a lower refractive index, a weight ratio of fluorine and phosphorus pentoxide in the core being larger than 1 (one), which is substantially free from unstability of the glass structure.

Abstract: In an optical fiber preform fabrication method having the steps of decomposing a glass raw material in a flame so that fine glass particles are produced; depositing the fine glass particles on a seed rod to form a porous preform; and consolidating the porous preform into a transparent optical fiber preform, use is made of a burner having a raw material supply orifice for supplying the glass raw material and a plurality of flame forming orifices deposed around the raw material supply orifice sequentially for forming a plurality of flames, respectively. The flame speed V.sub.k of a kth flame, the flame speed V.sub.k+1 of a (k+1)th flame surrounding outwardly of the kth flame and the flow speed Vm of the glass raw material are determined in a suitable manner. The glass raw material is supplied to the multi-flame produced by the burner in which the kth flame is positioned rearwardly of the (k+1)th flame to synthesize the fine glass particles.

Abstract: In an optical fiber preform fabrication method having the steps of decomposing a glass raw material in a flame so that fine glass particles are produced; depositing the fine glass particles on a seed rod to form a porous preform; and consolidating the porous preform into a transparent optical fiber preform, use is made of a burner having a raw material supply orifice for supplying the glass raw material and a plurality of flame forming orifices disposed around the raw material supply orifice sequentially for forming a plurality of flames, respectively. The flame speed V.sub.k of a kth flame, the flame speed V.sub.k+1 of a (k+1)th flame surrounding outwardly of the kth flame and the flow speed Vm of the glass raw material are determined in a suitable manner. The glass raw material is supplied to the maluti-flame produced by the burner in which the kth flame is positioned rearwardly of the (k+1)th flame to synthesize the fine glass particles.

Abstract: A device is disclosed for supplying a glass raw material gas in the form of the mixed gas consisting of the glass raw material gas and the carrier gas to a vapor deposition device for producing a preform of an optical fiber, the supply device including a secondary raw material container having a pressurizable interior and provided adjacent to a main raw material container. The bottoms, or areas near the bottoms, of the two containers are interconnected via a pipe including at a mid portion thereof a switching valve and a device for adjusting the flow rate of the raw material liquid between the two containers. Liquid level detectors are provided in one or both containers to maintain the constant volume of the liquid raw material so as to provide a constant state inside the main raw material container. The operation of this device can easily be entirely automated.