A method for preparing optical fibers formed with high-particle-coated porous polymeric outer coating layer is provided. The method includes preparing a coating suspension solution by dispersing a plurality of particles into an organic solvent system, immersing one or more optical fibers into the coating suspension solution, removing the one or more optical fibers from the coating suspension solution to form high-particle-coated porous polymeric outer coating layer after drying. Concentrations and compositions of the particles in the coating suspension solution, concentrations and compositions of the organic solvent system, the period of time of immersing, or the external environment are adjusted such that the optical fibers is formed with high-particle-coated polymeric outer coating layers having desirable coating masses, coating thicknesses, or coating morphologies.

A method of fabricating an optical fiber ribbon is provided, the method including arranging a plurality of optical fibers adjacent to each other along a length of the optical fiber ribbon, applying an adhesive to the plurality of optical fibers, intermittently exposing the adhesive to a curing catalyst in at least one interstice between two adjacent optical fibers of the plurality of optical fibers to create bonding regions along the length of the optical fiber ribbon, and removing uncured adhesive from the plurality of optical fibers.

An optical fiber comprises a glass fiber having a core and a cladding with which the core is covered, and a coating resin layer with which the glass fiber is covered, the coating resin layer having a colored layer of a thickness of 10 μm or more, wherein a change rate of a yellow index of the coating resin layer after aging due to temperature and humidity under an environment of 85° C. and 85% RH for 30 days is 5 or less per day.

An optical fiber comprises a glass fiber, and a coating resin layer having a primary resin layer and a secondary resin layer, wherein the primary resin layer consists of a cured resin composition containing an oligomer, a monomer and a photopolymerization initiator, the oligomer is a reaction product of a specific polyol compound, a polyisocyanate compound, and a hydroxyl group-containing acrylate compound, the photopolymerization initiator includes 2,4,6-trimethylbenzoyldiphenyl phosphine and 1-hydroxycyclohexyl phenyl ketone at a mass ratio of 5:1 to 1:1, and a content of 2,4,6-trimethylbenzoyldiphenyl phosphine in the resin composition is 1.5 to 2.5% by mass.

Multi-core optical fiber ribbons and methods for making multi-core optical fiber ribbons are described herein. In one embodiment, a multi-core optical fiber ribbon includes at least two core members formed from silica-based glass and oriented in parallel with one another in a single plane. Adjacent core members have a center-to-center spacing ≧15 microns and a cross-talk between adjacent core members is ≦−25 dB. In this embodiment each core member is single-moded with an index of refraction n.sub.c, and a core diameter d.sub.c. In an alternative embodiment, each core member is multi-moded and the center-to-center spacing between adjacent core members is ≧25 microns. A single cladding layer is formed from silica-based glass and surrounds and is in direct contact with the core members. The single cladding layer is substantially rectangular in cross section with a thickness ≦400 microns and an index of refraction n.sub.cl<n.sub.c.

A method for manufacturing an optical fiber ribbon includes: forming a colored layer on to each of a plurality of optical fibers and forming an optical fiber ribbon by curing a connecting material applied to a surface of the colored layer of each of the optical fibers to form connection parts that connect adjacent ones of the optical fibers. Forming the colored layer further includes: applying a coloring agent to the optical fibers and curing the coloring agent such that uncured resin remains on the surface of the colored layer. Forming the optical fiber ribbon further includes: applying the connecting material to the surface with the uncured resin and curing the connecting material and the uncured resin on the surface of the colored layer.

A method for manufacturing an optical fiber ribbon includes: forming a colored layer on to each of a plurality of optical fibers and forming an optical fiber ribbon by curing a connecting material applied to a surface of the colored layer of each of the optical fibers to form connection parts that connect adjacent ones of the optical fibers. Forming the colored layer further includes: applying a coloring agent to the optical fibers and curing the coloring agent such that uncured resin remains on the surface of the colored layer. Forming the optical fiber ribbon further includes: applying the connecting material to the surface with the uncured resin and curing the connecting material and the uncured resin on the surface of the colored layer.

Described herein are coated optical fibers including an optical fiber portion, wherein the optical fiber portion includes a glass core and cladding section that is configured to possesses certain mode-field diameters and effective areas, and a coating portion including a primary and secondary coating, wherein the primary coating is the cured product of a composition that possesses specified liquid glass transition temperatures, such as below −82° C., and/or a viscosity ratios, such as between 25° C. and 85° C., of less than 13.9. Also described are radiation curable coating compositions possessing reduced thermal sensitivity, methods of coating such radiation curable coating compositions to form coated optical fibers, and optical fiber cables comprising the coated optical fibers and/or radiation curable coating compositions elsewhere described.

Described herein are coated optical fibers including an optical fiber portion, wherein the optical fiber portion includes a glass core and cladding section that is configured to possesses certain mode-field diameters and effective areas, and a coating portion including a primary and secondary coating, wherein the primary coating is the cured product of a composition that possesses specified liquid glass transition temperatures, such as below −82° C., and/or a viscosity ratios, such as between 25° C. and 85° C., of less than 13.9. Also described are radiation curable coating compositions possessing reduced thermal sensitivity, methods of coating such radiation curable coating compositions to form coated optical fibers, and optical fiber cables comprising the coated optical fibers and/or radiation curable coating compositions elsewhere described.

A manufacturing method for an optical fiber, includes: drawing, while heating in a heating furnace, a lower end of an optical fiber preform that is to be an optical fiber having a core consisting of silica glass containing a rare earth element compound. The heating furnace has a temperature profile in which a temperature of the heating furnace increases to a maximum temperature T.sub.max and then decreases from an upstream side of the heating furnace toward a downstream side of the heating furnace. The temperature profile has a changing point at which the temperature decreases more steeply on the downstream side from a position where the maximum temperature T.sub.max is reached. At the maximum temperature, a temperature of the silica glass is higher than or equal to a glass transition temperature and the silica glass is in a single phase.