Sumitomo Electric Industries, Limited

Sumiden Opcom, Ltd.

Nippon Telegraph and Telephone Corporation

Soei International Patent Firm

Hiroaki Takimoto

Hiroshi Suganuma

Tomoyuki Hattori

Kazuhiko Arimoto

Hiroshi Yokota

Eisuke Sasaoka

Junichi Yoshikawa

Masumi Fukuma

Tetsuo Miyajiri

Tamio Turita

Kenichi Matsushita

Yuji Kobayashi

Yoichi Ishiguro

Ichiro Tsuchiya

Nobuo Tomita

Shigeru Semura

Katsuji Sakamoto

Masanori Fujikawa

Kiminobu Yoshida

Toshiyuki Wakinosono

Yoshiharu Okawa

Eisuke Sasoka

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.

Method of spacing fibers of optical fiber tapes and coupling the fibers

Arrayed optical fiber coupler and method of manufacturing the same

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. The reinforcing casing is preferably made of a material having substantially the same coefficient of linear expansion as that of quartz.

Reinforced multicore optical fiber coupler

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.

Protective structure for an optical fiber coupler and method for

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.

Method of producing optical fiber couplers using rectifier rods to

A clamp for optical fiber couplers manufacturing apparatus comprises a slotted member having a slot into which optical fibers are inserted and having an opening outwardly winder from the slot so that the optical fibers are introduced into the slot, and a pushing member movably disposed adjacent the slot for pushing the optical fibers through the opening into the slot, wherein the slotted member is away from the pushing member when the fibers are not clamped, and the slotted member is fixed at a position where the slotted member clamps the fibers.

Clamp for use in optical fiber coupler manufacturing apparatus

An object is to provide a coating removing apparatus and method in which it is not necessary to adjust the distance between edges of two, upper and lower, blades. An apparatus for removing a coating from a coated linear material, in which the upper blade is arranged so as to be brought into contact with the coating layer of the coated linear material, by its own weight, with a width in a direction perpendicular to the axis of the coated linear material.

Apparatus and method for removing a coating from a coated linear material

In an optical fiber coupler fabricating process where couplers are successively formed by heating, elongating and cutting a plurality of long optical fibers, light is led into the first end of the fiber, reflected at the second end of the coupler, and the reflected light is monitored by photodetectors. In this manner, an exact splitting ratio can be obtained. Techniques for minimizing measuring errors caused by the inter-reflected-light interference, the inter-Rayleigh-scattering-light interference, and the interference between the reflected light and the Rayleigh scattering light, while exploiting the advantageous feature of the reflection monitor method that the fiber connection work for each fiber coupler fabrication is not required are disclosed.

Reflection monitor optical fiber coupler manufacturing system and method

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.

Optical fiber coupler and its manufacturing method

The present invention provides a fiber coupler manufacturing apparatus comprising a pair of fiber holding portions and a fiber clamp disposed on each of the fiber holding portions for holding at least two optical fibers. A weight and pulley system is arranged wherein a first weight is coupled to each of the fiber holding portions to pull the fiber holding portions away from each other to apply tension to the optical fibers. A heating unit is disposed between the fiber holding portions and proximate to the optical fibers to heat the optical fibers. A second weight is coupled to either the fiber holding portions or the first weight and rests on a movable platform. As the movable platform descends in a vertical direction, the second weight applies additional force to the fiber holding portions and thus applies additional tension to the optical fibers.

Fiber coupler manufacturing apparatus having an automatic breaking test

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. The second process for producing an optical fiber coupler includes stripping the coating from at least one optical fiber, fixing the fiber so as to impart an axial stress thereto and then heating the bare portion of the stripped optical fiber thereby thinning the diameter of the heated portion, and then proceeding in the same manner as described with respect to the third through fifth steps of the first embodiment of the present invention. The processes according to the present invention enable a wide-band optical fiber coupler to be easily produced without using optical fibers of different structures but using optical fibers of identical structures.

Process for producing an optical fiber coupler

The invention provides an optical-coupler reinforcing member for fixing and reinforcing a fiber-coupler body and a method of performing the reinforcing. The reinforcing member includes heat-shrinkage tubes which are shrunk by heating, and a hollow protection pipe provided in the heat-shrinkage tubes. Cylindrical heat-fusible adhesive members are provided on opposite ends of the protection pipe, and heating is made such that a fusing portion of an optical-fiber coupler body is inserted through the reinforcing member so that the heat-fusible adhesive members and the heat-shrinkage tubes are shrunk by heating to thereby fix and reinforce the optical coupler body.

Optical-coupler reinforcing material and optical-coupler reinforcing

A reinforcing apparatus for an optical-fiber coupler is formed by placing fused optical fibers into a grooved U-shaped base structure. A cover which has a different longitudinal length than the base structure is centered on top of the U-shaped base structure. There exists an exposed groove section of the U-shaped base structure which lies on either side of the cover. An adhesive is inserted into these exposed groove sections so as to fix the reinforcing casing and the optical-fiber coupler to each other.

Growing community of inventors

Kanagawa, Japan

Hiroaki Takimoto