Provided are a multi-core fiber that enables complete automation of alignment in fusion splicing of multi-core fibers and an apparatus for manufacturing the multi-core fiber. A glass cladding of the multi-core fiber has a coating. A coating marker is drawn on the coating at a position that is determined by a predetermined rule that prescribes a positional relation with the core, for example, the coating marker is drawn on the coating near a specific core number. During fusion splicing of the multi-core fibers, two multi-core fibers are installed such that positions of the coating markers are substantially aligned. After the installation of the multi-core fibers, the coating markers of the two multi-core fibers are subjected to automatic rotational alignment by a fusion splicer to achieve a predetermined positional relation, and thus rotational positions between the two multi-core fibers are aligned.

Provided are a multi-core fiber that enables complete automation of alignment in fusion splicing of multi-core fibers and an apparatus for manufacturing the multi-core fiber. A glass cladding of the multi-core fiber has a coating. A coating marker is drawn on the coating at a position that is determined by a predetermined rule that prescribes a positional relation with the core, for example, the coating marker is drawn on the coating near a specific core number. During fusion splicing of the multi-core fibers, two multi-core fibers are installed such that positions of the coating markers are substantially aligned. After the installation of the multi-core fibers, the coating markers of the two multi-core fibers are subjected to automatic rotational alignment by a fusion splicer to achieve a predetermined positional relation, and thus rotational positions between the two multi-core fibers are aligned.

A method of marking an optical fiber includes forming an ink stream, moving an optical fiber over a fiber path adjacent the ink stream, and intermittently deflecting the ink stream with a gas jet so that the optical fiber at least partially enters the deflected ink stream so that the ink from the deflected ink stream forms spaced apart marks on the optical fiber outer surface. An optical fiber marking apparatus is also disclosed that includes payout and take modules that move the optical fiber over the fiber path, a marking unit configured to form an ink stream adjacent the fiber path, and an ink stream deflection device that causes the ink stream to deflect and overlap the fiber path so that ink from the ink stream forms spaced apart marks on the outer surface of the optical fiber.

A method of marking an optical fiber includes forming an ink stream, moving an optical fiber over a fiber path adjacent the ink stream, and intermittently deflecting the ink stream with a gas jet so that the optical fiber at least partially enters the deflected ink stream so that the ink from the deflected ink stream forms spaced apart marks on the optical fiber outer surface. An optical fiber marking apparatus is also disclosed that includes payout and take modules that move the optical fiber over the fiber path, a marking unit configured to form an ink stream adjacent the fiber path, and an ink stream deflection device that causes the ink stream to deflect and overlap the fiber path so that ink from the ink stream forms spaced apart marks on the outer surface of the optical fiber.

The present description provides multimode optical fibers with reduced cladding thickness. The optical fibers include a reduced-diameter glass fiber and/or reduced-thickness coatings. The overall diameter of the optical fibers is less than 210 m and examples with diameters less than 160 m are presented. Puncture resistant secondary coatings enable thinning of the secondary coating without compromising protection of the glass fiber. The optical fibers are suitable for data center applications and features high modal bandwidth, low attenuation, low microbending sensitivity, and puncture resistance in a compact form factor.

The present description provides multimode optical fibers with reduced cladding thickness. The optical fibers include a reduced-diameter glass fiber and/or reduced-thickness coatings. The overall diameter of the optical fibers is less than 210 m and examples with diameters less than 160 m are presented. Puncture resistant secondary coatings enable thinning of the secondary coating without compromising protection of the glass fiber. The optical fibers are suitable for data center applications and features high modal bandwidth, low attenuation, low microbending sensitivity, and puncture resistance in a compact form factor.

The apparatus and methods include moving an optical fiber over a fiber path that includes a marking location at which resides a marking unit that dispenses an ink-jet stream. A centering method is performed whereby the optical fiber is incrementally moved in a lateral direction through the path of the ink-stream and the mark number density of marks formed on the optical fiber is measured along with the optical fiber position. A process window is defined by the range of lateral fiber positions over which a target mark number density is formed on a consistent basis. A controller calculates an optimum fiber path position and stores it memory for future reference while also moving the fiber path to the optimum position. The initially wet ink marks are dried and the fiber coated with a transparent protective overcoat to form a coated and marked optical fiber.

The apparatus and methods include moving an optical fiber over a fiber path that includes a marking location at which resides a marking unit that dispenses an ink-jet stream. A centering method is performed whereby the optical fiber is incrementally moved in a lateral direction through the path of the ink-stream and the mark number density of marks formed on the optical fiber is measured along with the optical fiber position. A process window is defined by the range of lateral fiber positions over which a target mark number density is formed on a consistent basis. A controller calculates an optimum fiber path position and stores it memory for future reference while also moving the fiber path to the optimum position. The initially wet ink marks are dried and the fiber coated with a transparent protective overcoat to form a coated and marked optical fiber.

The present invention is a method for manufacturing an optical fiber which includes a resin coating step in which a resin is supplied to a resin coating section via piping, and a glass fiber is passed through the resin coating section such that the resin is coated on the outer circumference of the glass fiber. In the resin coating step, the temperature of the resin inside the piping is measured, and a heating unit provided on the outer circumference of at least some of the piping is controlled such that the temperature of the resin inside the piping reaches a set target temperature; and a viscometer is disposed in between the resin coating section and the piping on which the heating unit is provided, and the set value of the target temperature is adjusted such that the viscosity of the resin measured by the viscometer reaches a target viscosity.

The present invention is a method for manufacturing an optical fiber which includes a resin coating step in which a resin is supplied to a resin coating section via piping, and a glass fiber is passed through the resin coating section such that the resin is coated on the outer circumference of the glass fiber. In the resin coating step, the temperature of the resin inside the piping is measured, and a heating unit provided on the outer circumference of at least some of the piping is controlled such that the temperature of the resin inside the piping reaches a set target temperature; and a viscometer is disposed in between the resin coating section and the piping on which the heating unit is provided, and the set value of the target temperature is adjusted such that the viscosity of the resin measured by the viscometer reaches a target viscosity.