Abstract: The present invention provides a coated optical fiber in which a silica type optical fiber is coated with n layers (n being an integer of 2 or greater) of UV-curable resin, wherein the sum of respective contraction stress indices FI defined in the n layers of UV-curable resin by the following expression: FI [N]=(Young's modulus [MPa] of the UV-curable resin layer at −40° C.)×(cross-sectional area [mm2] of the UV-curable resin layer)×(effective linear expansion coefficient [10−6/° C.]/106)×(temperature difference 190[° C.]) is 3 [N] or less. The present invention can sufficiently prevent transmission characteristics from deteriorating in a low temperature environment.

Abstract: The present invention is a method of making a coated optical fiber comprising a first step of obtaining a glass optical fiber by drawing an optical fiber glass preform, a second step of forming the glass optical fiber with two layers of coating, and a third step of applying a twist to the glass optical fiber by using a swinging guide roller; wherein the glass optical fiber has a tension T of at least 2.2 (N/fiber) in the first step; and wherein T/R is 28 to 100, where R (m) is the barrel radius of the swinging guide roller, and the number of swinging movements of the swinging guide roller is 0.33 to 3.33 (s−1) in the third step. According to the present invention, the polarization mode dispersion (PMD value) of thus obtained coated optical fiber can reliably be reduced.

Abstract: In a method of making a ribbon type coated optical fiber 3 comprising the step of inserting a plurality of optical fibers 1 flatly arranged parallel to each other through a die orifice 11a so as to collectively coat the optical fibers with a coating resin 2, the ratio W/H of a clearance W in the width direction between the inner surface of the die orifice 11a and the outer surface of the optical fibers 1 to a clearance H in the thickness direction therebetween is set within the range of 1.0 to 2.5.

Abstract: The permanent magnet type reluctance electric motor includes a stator including a stator iron core and having armature coils placed inside slots, and a rotor provided with a plurality of magnetic barriers formed by cavities and placed on an inner side of the stator such that sections where a magnetic flux can easily pass (d-axis) and sections where a magnetic flux cannot easily pass (q-axis) are alternately formed, and made of a rotor iron core having permanent magnets in cavities. The rotor satisfies a relationship of PL/2&pgr;RWqave≧130, where Wqave [m] indicates an average thickness of the rotor iron core on an outer side in a radial direction of the rotor with respect to cavities arranged in a q-axis direction, L [m]; a width in a circumferential direction of the cavities, P; the number of poles and R [m]; the radius of the rotor.

Abstract: An apparatus for producing optical fiber ribbons which has a optical fiber gathering device, one or more coating applicators and a turn roller arranged in a straight line, with one or more alignment guide in plate form being provided on a travelling line of optical fibers or optical fiber ribbons upstream of the coating applicator. The alignment guide is chamfered to arch form on the side that contacts the optical fibers or the optical fiber ribbons. The alignment guide suppresses the optical fibers or the optical fiber ribbons from vibrating in a direction perpendicular to the direction of the arrangement of the optical fibers or the optical fiber ribbons.

Abstract: A collectively coating die device (2) is provided for applying coating resin in a lump to coated optical fibers (1) arranged in parallel on one and the same plane so as to form a plurality of optical fiber ribbons (16) at the same time. The collectively coating die device (2) has a nipple portion (9) and a die portion (10), a resin accumulation space (8) formed between the nipple portion (9) and the die portion (10). The nipple portion (9) has two parallel planes and having a plurality of optical fiber passageways (13) shaped like ellipses in section and provided in the direction perpendicular to the planes. The die portion (10) has two parallel planes and has a plurality of optical fiber passageways (14) shaped like ellipses in section and is provided in the direction perpendicular to the planes. Each of the optical fiber passageways (13) of the nipple portion (9) has a tapered portion.

Abstract: In a split type ribbon optical fiber core cable capable of being split into cables, there are a plurality of ribbon optical fiber core cable units, each of which are constituted by a plurality of colored optical fiber core cables arranged in a row; a coating resin of an ultraviolet curable resin wholly coats the plurality of colored optical fiber core cables; and a bonding resin of an ultraviolet curable resin bonds the ribbon optical fiber core cable units arranged in a row. In this cable, an adhesion strength between the coating resin and the bonding resin is in the range of 1 to 100 g/cm. Further, the bonding resin after curing has a Young's modulus of from 5 to 100 kg/mm.sup.2. The bonding resin after curing has an elongation coefficient of from 5 to 80%.

Abstract: An optical fiber ribbon is manufactured under a condition where, assuming that the optical fiber ribbon has a thickness of 2d (mm), a guide roller has a diameter of 2R (mm), and a period of time till the optical fiber ribbon comes into contact with the guide roller after leaving an ultraviolet irradiation apparatus is t (ms), a relationship of d/?(R+d).times.t!<0.2 is satisfied. Accordingly, no damages are imparted to the optical fiber ribbon, and no micro-bendings occur in its coated optical fibers, whereby the transmission characteristic can be prevented from deteriorating.

Abstract: In a method for producing an optical fiber ribbon, a plurality of coated optical fibers is fed out so that the plurality of coated optical fibers are arranged in a plane in a concentrator. A ribbon matrix composed of ultraviolet-curing resin is applied onto the plurality of coated optical fibers in a coater. Ultraviolet rays is radiated to cure the ribbon matrix. The plurality of coated optical fibers are arranged at intervals in a plane in the concentrator.

Abstract: Optical fibers are fixed to elongating tables by optical fiber fixing jigs. Coatings are removed from portions of the fibers and respective fibers of two different groups are placed into tight contact with one another. The fibers are then heated by a gas burner 4A so as to be welded integrally with each other, and are then elongated. In one preferred embodiment, the fibers are arranged such that there are gaps therebetween. These gaps are substantially 250 .mu.m. The gaps are sufficiently wide that heating gas flows in a manner such that all the optical fiber strands are heated uniformly to make it possible uniform welding and elongation.

Abstract: In a case where an arrayed optical fiber coupler obtained from a tape ribbon 1 is fixed to an reinforcement case 3, a glass portions 2b as a non-elongated portion outside of the elongated portions 2c of the coupler and a protection coating layers 2a at the back thereof are fixed to the reinforcement case 3 with an adhesive layer 4. A collectively coating resin layer 1a of the tape ribbon 1 is not fixed to the reinforcement case 3. The resin layer 1a is fixed to the reinforcement case 3 with a soft adhesive layer 5 different from the above adhesive layer 4, if necessary. As the resin of the adhesive layer 4, there is preferable an adhesive having the viscosity of 50 to 200 P and thermosetting property in addition to ultraviolet cure property.

Abstract: A coated optical fiber unit having at least two coated optical fibers, each of which has a coloring layer as the outermost layer and which are coated together with a bundling coating layer, is disclosed. The bundling coating layer and the coloring layer are both treated to suppress their bonding, there by allowing the coloring layer to not be removed at the same time as the removal of the bundling coating layer. The releasing agent added to the bundling coating layer and the coloring layer does not swell the resins in the layers, or cause peeling of the protective coating layer from the optical fiber.

Abstract: A reinforced structure for a multicore optical fiber coupler wherein a longitudinal coating resin of first and second multicore optical fibers, each having a plurality of optical fiber stands positioned in parallel arrangement to each other and each collectively coated with a respective coating resin, is partially removed so as to expose glass portions of the optical fiber strands of each of the optical fibers. The exposed glass portions are then fused and extended. The fused and extended portions are then accommodated in a plurality of grooves formed in a reinforcing casing. The non-extended portions, which are located on opposite ends of the fused and extended portions in the extending direction, are also accommodated on the surface of the reinforcing casing. The optical fibers are secured to the reinforcing casing with adhesive, which is applied to the non-extended portions of the fibers.

Abstract: A tape form optical fiber wire comprising at least one set of at least two optical fibers each of which has a protective coating layer and which are arranged in parallel in the same plane, at least one set of the optical fibers being integrated by at least one common coating layer, in which the common coating layer contains a main component of a common coating resin and a component having a poor compatibility with the main component, in which wire, no strain is generated in the optical fibers when the wire is bent.

Abstract: An optical waveguide module according to the present invention comprises an optical waveguide substrate having an optical waveguide formed therein, an optical waveguide holder for mounting the optical waveguide substrate thereon, an optical fiber connector supporting an optical fiber therein, and an optical fiber holder for mounting the optical fiber connector thereon, the end faces of the optical waveguide holder and the optical fiber holder are brought into contact with each other while aligning the optical waveguide and the optical fiber, the end faces of the optical waveguide substrate and the optical fiber connector are bonded at least partially through a gap, and a hardening matching agent having a refractive index matching with those of the optical waveguide and the optical fiber is filled in the gap.

Abstract: The present relates to the protective structure for an optical fiber coupler made from bare fiber parts of a plurality of optical fibers therein, the bare fiber parts being formed by removing the coating of the plurality of optical fibers and comprises a case made of material having a coefficient of thermal expansion equivalent to optical fibers and having space for enclosing the optical fiber coupler, and fiber supporting portions, being arranged inside of the space of the case and being fused with the bare fiber parts.

Abstract: Optical fibers are fixed to elongating tables by optical fiber fixing jigs. Coatings are removed from portions of the fibers and respective fibers of two different groups are placed into tight contact with one another. Rectifier rods, supported movably by rectifier rod supporting members, are disposed outside the optical fiber strands. The fibers are then heated by a gas burner 4A so as to be welded integrally with each other, and are then elongated. By using rectifier rods, the outside optical fiber strands of the groups being welded are not so strongly heated that uniform welding and elongation can be realized. In one preferred embodiment, the fibers are arranged such that there are gaps therebetween. These gaps are substantially 250 .mu.m. The gaps are sufficiently wide that heating gas flows in a manner such that all the optical fiber strands are heated uniformly to make it possible uniform welding and elongation.

Abstract: An optical fiber coupler having a crosstalk characteristic of at least 18 dB. The optical fiber coupler includes a plurality of optical fibers. A length of glass in the optical fibers is exposed by removing the covering. The glass lengths are fused together and extended, during which time the fibers are twisted and subjected to a tension. The twisted fibers are then fixed to a protecting member while the tension is sustained.

Abstract: The first process for producing an optical fiber coupler includes a first step wherein at least one of the optical fibers to be used is stripped of the coating, a second step in which the bare portion of that optical fiber is heated for a predetermined time to diffuse the dopants, a third step wherein the other optical fibers which have not been heat-treated are stripped of their coating, a fourth step in which the bare portions of all the optical fibers are heated as they are brought into intimate contact, thereby forming a unitary portion, and a fifth step wherein the unitary portion is drawn via heating to form the coupling portion of an optical fiber coupler.

Abstract: A coated optical fiber of the invention is constructed by coating an energy beam curable resin onto the outer periphery of a wiredrawn optical fiber and curing the resin by radiating an energy beam to the resin to thereby provide a coating layer on the optical fiber. The temperature of peak mechanical loss tangent, Tan .delta., of the energy beam curable resin prior to curing is 25.degree. C. or lower.