Abstract: The ferrule part 16 comprises ferrule 60, first and second optical fibers 62 and 64, and optical filter 68. Ferrule 60 has first and second end surface 60a and 60b, ferrule insertion hole 60c, and groove 68. Ferrule insertion hole 60c extends along a first axis, and accommodates first and second optical fibers 62 and 64. Groove 66 extends along a second axis crossing the first axis, and extends so as to extend across ferrule 60. Groove 66 is provided along a plane defined by the second axis and a third axis perpendicular to the first and second axes. Optical filter 68 can reflect a part of light incident on one surface 68b of the pair of surfaces of optical filter 68, and can transmit a part of the light incident on other surface 68a.

Abstract: The ferrule part 16 comprises ferrule 60, first and second optical fibers 62 and 64, and optical filter 68. Ferrule 60 has first and second end surface 60a and 60b, ferrule insertion hole 60c, and groove 68. Ferrule insertion hole 60c extends along a first axis, and accommodates first and second optical fibers 62 and 64. Groove 66 extends along a second axis crossing the first axis, and extends so as to extend across ferrule 60. Groove 66 is provided along a plane defined by the second axis and a third axis perpendicular to the first and second axes. Optical filter 68 can reflect a part of light incident on one surface 68b of the pair of surfaces of optical filter 68, and can transmit a part of the light incident on other surface 68a.

Abstract: An optical communication system of the optical feed forward type in which a main optical signal and a distortion signal are transmitted by a common optical fiber line from the transmission part to the reception part.

Abstract: An optical communication arrangement (apparatus and method) employing intensity modulation. The parameters of the optical communication system that impose a maximum influence on the modulation distortion are monitored whenever necessary, and the operating parameters of the optical communication system can be corrected in accordance with the parameters being monitored. The system employs the intensity modulation in which a delaying mechanism having a low delay accuracy and a delaying mechanism having a high delay accuracy are provided to completely suppress the modulation distortion.

Abstract: A method of fabricating an optical branching and coupling device includes the steps of preparing at least a pair of coated optical fibers; partly stripping the coating of the optical fibers; and fixedly inserting the coating stripped portions of the optical fibers into a pair of comb-shaped grooves under a condition prior to a unification step which is free from tension and torsional stress in an optical axial direction to bring the coating stripped portions into contact with each other between the comb-shaped grooves. The method also includes the steps of melting the coating stripped portions thus contacting each other by heating to unify the coating stripped portions and extending the coating stripped portions in the optical axial direction while in the melted state.

Abstract: An optical connector comprises an optical fiber guide member consisting of a grooved substrate and a cover plate, the substrate having optical fiber guide grooves and guide pin grooves cut into its top surface, and the cover plate being joined to the substrate to cover the optical fiber guide grooves but to leave at least part of the guide pin grooves exposed; a pressing member which is movable in the vertical direction of the guide pin grooves and is provided above the guide pin grooves to elastically press guide pins which are positioned on the guide pin grooves downward; and coupling clips enhancing the force of elastic pressure being exerted on the guide pins so as to secure the joining of optical fibers.

Abstract: An optical connector and splicer including an optical fiber positioning member for optical coupling of optical fibers where the coupling is assisted by at least two guide pins. The optical fiber positioning member comprises a substrate plate and a flat plate. The substrate plate has optical fiber grooves and guide pin grooved each formed at one surface thereof for positioning the one optical fibers and said guide pins, respectively. The flat plate has a flat surface confronting with the grooves surface of the substrate plate. An exposed area is formed on a part of the substrate plate where said flat plate is not joined for facilitating an insertion of the optical fibers into the optical fiber grooves.

Abstract: An optical connector ferrule for use in an optical coupling of optical fibers includes an insertion member, the insertion member comprising a guide capillary for positioning said optical fibers, which comprises a flat plate and a guide substrate having optical fiber guide grooves in one surface thereof, said flat plate being bounded to said guide substrate to form optical fiber guide holes into which said optical fibers are inserted; a reinforcing pipe for surrounding said guid capillary; and a resin-molded area provided between said guide capillary and said reinforcing pipe for insert-molding said guide capillary within said reinforcing pipe.

Abstract: A method of identifying an aimed coated fiber in an optical transmission network. Identification of the aimed coated fiber in the optical transmission network is accomplished between its upstream and downstream ends during transmission of an optical signal without disrupting the capabilities of an optical communication network or causing deterioration of the optical signal being transmitted.

Abstract: A multi-core optical fiber with improved dimensional accuracy is produced by a method comprisinginserting at least two core glass rods in bores formed in a cladding glass rod having a refractive index lower than that of the core glass rods to be inserted,heating a composite of the cladding glass rod and the core glass rods to integrate them together, anddrawing the integrated composite to fabricate a multi-core optical fiber.The drawing may be carried out simultaneously with the integration step.

Abstract: An optical connector comprises an optical fiber connector ferrule which comprises a substrate plate having at least one optical fiber groove and pin grooves each being formed at one surface thereof, and a cover plate joined to the substrate plate to form at least one optical fiber groove holes into which an optical fiber is inserted; a guide pin means to be inserted into the pin grooves for coupling the optical fiber connector ferrule with another; and means for absorbing the variation in the diameter of the guide pin means.

Abstract: A tape and slot type optical cable having a core with groove dimensions that hold tape shaped optical fibers and also improve the transmission and mechanical strength characteristics of the optical cable. The dimensions require that for a groove having a depth D.sub.S and a width W.sub.S and a predetermined plurality n of optical fiber bundles of thickness T and width W.sub.T that the equations following equations be satisfied:1.2<(W.sub.S /W.sub.T)<1.451.3<(D.sub.S /nT)<1.

Abstract: An optical connector and splicer including an optical fiber positioning member for optical coupling of optical fibers where the coupling is assisted by at least two guide pins. The optical fiber positioning member comprises a substrate plate and a flat plate. The substrate plate has optical fiber grooves and guide pin grooves each formed at one surface thereof for positioning the one optical fibers and said guide pins, respectively. The flat plate has a flat surface confronting with the grooved surface of the substrate plate. An exposed area is formed on a part of the substrate plate where said flat plate is not joined for facilitating an insertion of the optical fibers into the optical fiber grooves.

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: Disclosed herein is an independent optical ferrule, an optical connector employing the independent ferrule, and replaceable plug unit employing the independent ferrule. Also disclosed is a method of using the replaceable plug unit employing the independent ferrule. The independent ferrule includes a stem portion having both ends each confronting ones of optical elements such as an end ferrule. The independent ferrule further includes at least one optical fiber held in a fixed position in the stem and having the both ends flush with the end faces of the stem. The independent ferrule also includes a collar adapted to serve as positioning member upon assembly of said independent ferrule into the optical connector or the replaceable plug unit.

Abstract: A ferrule for an optical connector made of a resin composition comprising a resin and carbon fiber as a filler having larger flexural strength and small mold shrinkage factor. The ferrule has a metal tube around its body that is embedded in its flange portion for added flexural rigidity.

Abstract: An optical connector for joining ends of optical fibers, including an adapter formed with at least one claw and a plug coupled detachably with the adapter. The plug includes an insertion guide to be inserted into the adapter, an ejector and an urging member for urging the ejector in an axial insertion direction, while the insertion guide is formed, on its outer periphery, with a projection and a recess such that the claw is caused to ride over the projection into engagement with the recess at the time of coupling of the plug with the adapter.

Abstract: An optical fiber cable plug manufacturing method providing easy connection between large numbers of optical fibers. The protective cover layer of an optical fiber cable is removed from its middle part to expose the coated optical fibers and the tensile strength member, and the tensile strength member is cut into two parts. Then, the coated optical fibers thus exposed are partially uncoated. Coupling members are disposed along the exposed parts of the optical fibers and molded together with the optical fibers with resin to provide a molding. The molding is cut perpendicularly to its longitudinal axis into two symmetrical parts, and the cut end faces are polished to provide two symmetrical optical fiber cable plugs.

Abstract: A fiber for optical transmission composed of a core having a substantially parabolic distribution of refractive index, a first cladding layer formed around the core having a refractive index equal to that of the periphery of the core and a thickness of 1/100 to 1/20 the diameter of the core, a second cladding layer formed around the first cladding layer having a refractive index smaller than that of the first cladding layer, and a third cladding layer formed around the second cladding layer having a refractive index greater than that of the second cladding layer. The fiber for optical transmission having such a structure has a broad bandwidth of transmitted light.

Abstract: An optical connector for joining exposed fiber ends of coated fibers and a method of manufacturing a pair of ferrules for the optical connector. The optical connector includes a pair of the ferrules each having a flange, the coated fiber and a metal pipe molded integrally with one another by using molding resin, a coupling pin fitted through holes of the ferrules, a sleeve for receiving the metal pipes of the ferrules, and a housing member for axially clamping the ferrules to each other.