Abstract: An optical fiber connecting part has a ferrule, and a guide bore penetrating through the ferrule and configured to guide an optical fiber to be inserted. The guide bore has a first bore provided at one end of the ferrule, through which the optical fiber is inserted into the ferrule, a second bore provided at another end of the ferrule, the second bore having an inner diameter smaller than an inner diameter of the first bore, and an intermediate bore provided between the first bore and the second bore to directly connect between the first bore and the second bore. A center axis of the second bore is shifted from a center axis of the first bore.

Abstract: An optical connector that requires no complicated fabrication operation such as highly accurate optical axis alignment and that permits an efficient pick up of part of the communication signal light being on-propagation along an optical transmission line, is provided.

Abstract: An optical connector according to the present invention comprises a ferrule and a V-groove board connected to the ferrule, wherein a first optical fiber and a second optical fiber being butt jointed in a V-groove formed in the V-groove board so as to be interconnected; the second optical fiber is connected to the first optical fiber through a refractive index matching material of cross-link curing type applied to an end surface on the V-groove board side of the first optical fiber; and spaces are provided in the V-groove so as to relax stress loaded on the refractive index matching material of cross-link curing type.

Abstract: A composite cable that is able to prevent both the unfastening of the cable end from the connector and the occurrence of the bending distortion of the optical fiber, to both of which the expansion and shrinkage of the overall sheath is responsible, is provided. The composite cable comprises a stranded wire that is a strand of a plurality of insulated conductors each of which is a conductor with insulation covering thereon, an optical fiber ribbon that has a plurality of optical fibers parallelly-arranged in a row, and an overall sheath that covers the stranded wire and the optical fiber ribbon in a bundle, wherein the composite cable has a deterrent positioned on outer side of the stranded wire and the optical fiber ribbon parallelly-arranged in a row along the width direction of the overall sheath for deterring expansion and shrinkage of the overall sheath.

Abstract: An optical connector that permits an optical fiber ribbon to be led out in multiple directions and an optical fiber module that uses the optical connector are provided. The optical connector 1 comprises a connector main body 2 and a guide groove 4 formed on the connector main body in which a optical fiber ribbon 151 is arranged, wherein the guide groove is comprised of an end face holding slot 5, a vertical guiding face 7, an arcuate guiding face 9 formed in arc-shape, and a positioning face 10 for widthwise positioning and fixing the optical fiber ribbon and wherein the vertical guiding face and the arcuate guiding face and the positioning face define a space that opens toward a top face of the connector main body; and the optical fiber module comprises the optical fiber ribbon and the optical connector.

Abstract: A forming method of a refractive index matching film comprises steps: one end of an optical fiber is brought into contact with a liquid surface of a photo-curable refractive index matching solution; curing reaction light is made incident to the opposite end of the optical fiber and is emitted through the one end of the optical fiber so as to cure preliminarily the photo-curable refractive index matching solution in contact with the one end of the optical fiber; the curing reaction light is tentatively stopped; the one end of the optical fiber is separated from the liquid surface of the photo-curable refractive index matching solution; and the curing reaction light is made incident again from the opposite end of the optical fiber so as to cure the preliminarily cured photo-curable refractive index matching solution and form a refractive index matching film.

Abstract: In an embodiment of the invention, an optical connector for optically coupling respective end faces of two optical fiber cables including an optical fiber composed of a core and a cladding and a covering layer covering the optical fiber includes a protection sleeve, a cable insertion tube disposed in the protection sleeve for inserting thereinto and butting the respective end faces of the two optical fiber cables, an uncured refractive index matching material disposed between the protection sleeve and the cable insertion tube, and a supply hole formed in the cable insertion tube for supplying the uncured refractive index matching material to an inside of the cable insertion tube. The cable insertion tube includes a cable receiving room for receiving an end of the two optical fiber cables inserted, a fiber receiving room for receiving the optical fiber, and a covering removal member formed at a boundary of the cable receiving room and the fiber receiving room for removing the covering layer.

Abstract: An optical connector has a ferrule, an optical fiber connector disposed at an back end of the ferrule, an internal optical fiber inserted into the ferrule and the optical fiber connector, the internal optical fiber being adapted to butt-connect at a back end face thereof to an external optical fiber to be inserted into the optical fiber connector, and a refractive index matching body attached to the back end face of the internal optical fiber. The refractive index matching body has a cross-linked and hardened cross-linkable refractive index matching agent including a stress-strain relaxation agent.

Abstract: In an embodiment of the invention, an optical connector for optically coupling respective end faces of two optical fiber cables including an optical fiber composed of a core and a cladding and a covering layer covering the optical fiber includes a protection sleeve, a cable insertion tube disposed in the protection sleeve for inserting thereinto and butting the respective end faces of the two optical fiber cables, an uncured refractive index matching material disposed between the protection sleeve and the cable insertion tube, and a supply hole formed in the cable insertion tube for supplying the uncured refractive index matching material to an inside of the cable insertion tube. The cable insertion tube includes a cable receiving room for receiving an end of the two optical fiber cables inserted, a fiber receiving room for receiving the optical fiber, and a covering removal member formed at a boundary of the cable receiving room and the fiber receiving room for removing the covering layer.

Abstract: In an embodiment of the invention, an optical connector for optically coupling respective end faces of two optical fiber cables including an optical fiber composed of a core and a cladding includes a beat shrinkable tube, a cable insertion tube disposed in the heat shrinkable tube for inserting thereinto and butting the respective end faces of the two optical fiber cables, an uncured refractive index matching resin disposed between the beat shrinkable tube and the cable insertion tube, and a resin supply hole formed in the cable insertion tube for supplying the uncured refractive index matching resin to an inside of the cable insertion tube.

Abstract: A communication light detecting device interconnecting light transmission paths and collocated therebetween, comprises: an optical coupling body including a core portion for photo coupling with the light transmission paths, and a light extracting portion for extracting a part of the communication light as a leakage light; and a light detecting portion having a light receiving member for receiving the leakage light. The light extracting portion is preferable to possess a lower refractive index than that of the core portion. Besides, the light extracting portion is preferable to include a light detecting use groove with a groove width of 50 ?m or more and 140 ?m or less formed by cutting and separating the core portion. Besides, the light extracting portion is preferable to be the optical coupling body in which outer diameter of the core portion is different from the outer diameter of a core of the light transmission path.

Abstract: An optical fiber includes a core, a clad having a plurality of air holes at a periphery of the core, and a hardening resin filled in a sealed portion at an end of the plurality of air holes. The hardening resin after hardening has a fill length of 7 mm to 8 mm. An optical fiber connection structure includes the optical fiber with an end face butt-connected to another optical fiber. An optical connector includes the optical fiber, and a ferrule to which the optical fiber is attached.

Abstract: An optical connector has a ferrule, an optical fiber connector disposed at an back end of the ferrule, an internal optical fiber inserted into the ferrule and the optical fiber connector, the internal optical fiber being adapted to butt-connect at a back end face thereof to an external optical fiber to be inserted into the optical fiber connector, and a refractive index matching body attached to the back end face of the internal optical fiber. The refractive index matching body has a cross-linked and hardened cross-linkable refractive index matching agent including a stress-strain relaxation agent.

Abstract: An optical fiber includes a core, a clad formed around the core, a plurality of holes being formed in the clad, and a hardening resin having a moisture permeability equal to or less than 0.5 g/cm2·24 hr, in which the hardening resin is filled in a vicinity of an end face of the holes.

Abstract: An optical fiber includes a core, a clad having a plurality of air holes at a periphery of the core, and a hardening resin filled in a sealed portion at an end of the plurality of air holes. The hardening resin after hardening has a fill length of 7 mm to 8 mm. An optical fiber connection structure includes the optical fiber with an end face butt-connected to another optical fiber. An optical connector includes the optical fiber, and a ferrule to which the optical fiber is attached.

Abstract: An optical connector according to the present invention comprises a ferrule and a V-groove board connected to the ferrule, wherein a first optical fiber and a second optical fiber being butt jointed in a V-groove formed in the V-groove board so as to be interconnected; the second optical fiber is connected to the first optical fiber through a refractive index matching material of cross-link curing type applied to an end surface on the V-groove board side of the first optical fiber; and spaces are provided in the V-groove so as to relax stress loaded on the refractive index matching material of cross-link curing type.

Abstract: An optical connector having: a ferrule into which a first optical fiber is inserted; an optical fiber connector disposed at an back end of the ferrule; and a cross-linkable refractive index matching member attached onto an end face on a back end side of the first optical fiber. The end face on the back end side of the first optical fiber and an end face of a second optical fiber to be inserted into the optical fiber connector from a back end side thereof are to be connected by a butting connection. The cross-linkable refractive index matching member is formed such that a cross-linkable refractive index matching agent is coated on the end face on the back end side of the first optical fiber, and the coated agent is cross-linked and hardened.

Abstract: A forming method of a refractive index matching film comprises steps: one end of an optical fiber is brought into contact with a liquid surface of a photo-curable refractive index matching solution; curing reaction light is made incident to the opposite end of the optical fiber and is emitted through the one end of the optical fiber so as to cure preliminarily the photo-curable refractive index matching solution in contact with the one end of the optical fiber; the curing reaction light is tentatively stopped; the one end of the optical fiber is separated from the liquid surface of the photo-curable refractive index matching solution; and the curing reaction light is made incident again from the opposite end of the optical fiber so as to cure the preliminarily cured photo-curable refractive index matching solution and form a refractive index matching film.

Abstract: It is intended to provide a host microorganism whereby the expression of a gene encoding a target protein can be effectively elevated in the case of transferring the gene. It is also intended to provide a transformant whereby a target protein can be produced at a high efficiency. It is further intended to provide a production process whereby a target protein can be produced at a high productivity. A microorganism which belongs to Eumycota and lacks the major isomaltose synthase. A gene encoding a target protein is transferred into the microorganism to give a transformant. Then the transformant is cultured under conditions allowing the expression of the transferred gene to thereby produce the protein.

Abstract: It is intended to provide a selection marker gene with the use of auxotrophy as an indication which is usable in transforming a fungus. Namely, a selection marker comprising a quinolinate phosphoribosyltransferase gene isolated from Aspergillus oryzae.