A method of marking an optical fiber that includes directing a laser beam onto a first colored layer of an optical fiber. The optical fiber includes a core and a cladding surrounding the core, the first colored layer surrounds the cladding, and the laser beam modifies the first colored layer to form one or more laser-modified regions along an outer surface of the first colored layer.

A solution is provided comprising boron nitride nanotubes (BNNTs) in a liquid solvent. An optical waveguide, such as an optical fiber, is contacted with the solution so as to form a layer of the solution supported on at least a portion of the optical waveguide. The liquid solvent is then removed from the layer of the solution supported on the optical waveguide in order to form a coating of the BNNTs on the optical waveguide. Further provided is a BNNT coated optical waveguide for use as a sensor.

A method of manufacturing an optical fiber includes applying a curable resin composition containing a photopolymerization initiator so that an outer circumference of a glass fiber including a core and a cladding is coated, and forming a coating layer by radiating an ultraviolet ray to the curable resin composition and curing the curable resin composition. Forming the coating layer includes providing two or more non-radiation periods and intermittently radiating the ultraviolet ray three or more times so that a total time of the non-radiation periods is 0.010 seconds or more.

Embodiments of the current disclosure include small diameter single-mode optical fibers having gratings and methods of forming thereof. In some embodiments, methods of forming a small diameter single-mode optical fibers having gratings include providing an optical fiber having a core and cladding with a combined outer diameter of 100 μm to 125 μm and a coating having a thickness of less than or equal to 20 μm, wherein the coating comprises one of: (i) a high-modulus coating layer surrounding the cladding region; or (ii) a low-modulus coating layer surrounding the cladding region and a high-modulus coating layer surrounding the low-modulus coating layer; and exposing the core, through the coating, to a pattern of ultraviolet radiation to form an optical grating within the core.

In curing a matrix material of a rollable optical fiber ribbon, ultraviolet light may be concentrated in a selected range of wavelengths to avoid further curing the primary coating of each fiber. A ribbon may be made by aligning the fibers, each having at least a primary coating, into a ribbon shape, applying a matrix material in intermittently distributed portions along the ribbon-shaped group of fibers, and exposing the ribbon-shaped group of fibers and applied matrix material to ultraviolet light concentrated in a range of wavelengths absorbed more by the matrix material than by the primary coating.

An optical fiber coating die assembly is provided. The optical fiber coating die assembly includes a housing defining a guide chamber having an inlet for receiving optical fiber and an outlet, a guide die located at the outlet of the guide chamber, and a sizing die. The optical fiber coating die assembly also includes a coating applicator disposed between the guide die and the sizing die, and a tube operatively coupled to the inlet of the guide chamber and axially aligned with the chamber to receive the optical fiber fed into the guide chamber and provide a barrier to air flow.

The method for producing a resin composition for a secondary coating of an optical fiber comprises a step of reacting a polyol, a diisocyanate and a hydroxyl group-containing (meth)acrylate in the presence of a (meth)acrylate not having a hydroxyl group to obtain a mixture of urethane (meth)acrylate and the (meth)acrylate not having a hydroxyl group, and a step of adding a photopolymerization initiator to the mixture to obtain a resin composition, and a hydroxyl value of the (meth)acrylate not having a hydroxyl group is 12.0 mgKOH/g or less.

The method for producing a resin composition for a secondary coating of an optical fiber comprises a step of reacting a polyol, a diisocyanate and a hydroxyl group-containing (meth)acrylate in the presence of a (meth)acrylate not having a hydroxyl group to obtain a mixture of urethane (meth)acrylate and the (meth)acrylate not having a hydroxyl group, and a step of adding a photopolymerization initiator to the mixture to obtain a resin composition, and a hydroxyl value of the (meth)acrylate not having a hydroxyl group is 12.0 mgKOH/g or less.

A resin composition comprises a base resin containing a urethane (meth)acrylate oligomer, a monomer and a photopolymerization initiator, and a hydrophobized spherical inorganic oxide, wherein the inorganic oxide is dispersed in the resin composition and a content of the inorganic oxide is 1 to 60% by mass based on a total amount of the resin composition.

A resin composition comprises a base resin containing a urethane (meth)acrylate oligomer, a monomer and a photopolymerization initiator, and a hydrophobized spherical inorganic oxide, wherein the inorganic oxide is dispersed in the resin composition and a content of the inorganic oxide is 1 to 60% by mass based on a total amount of the resin composition.