An optical fiber coating apparatus that provides increased gyre stability and reduced gyre strength, thereby providing a more reliable coating application process during fiber drawing includes a cone-only coating die having a conical entrance portion with a tapered wall angled at a half angle , wherein 225, and a cone height L.sub.1 less than 2.2 mm, and a cylindrical portion having an inner diameter of d.sub.2, wherein 0.1 mmd.sub.20.5 mm and a cylindrical height of L.sub.2, wherein 0.05 mmL.sub.21.25 mm; a guide die having an optical fiber exit, the guide die disposed adjacent the cone-only coating die such that a wetted length (L.sub.5) between the optical fiber exit of the guide die and the entrance of the cone-only coating die is from 1 mm to 5 mm; and a holder for holding the cone-only coating die and the guide die in a fixed relationship defining a coating chamber between the guide die and the cone-only coating die, the coating chamber having an inner radius L.sub.6 from the optical fiber axis to an inner wall of the holder that is from 3 mm to 10 mm.

An optical fiber coating apparatus that provides increased gyre stability and reduced gyre strength, thereby providing a more reliable coating application process during fiber drawing includes a cone-only coating die having a conical entrance portion with a tapered wall angled at a half angle , wherein 225, and a cone height L.sub.1 less than 2.2 mm, and a cylindrical portion having an inner diameter of d.sub.2, wherein 0.1 mmd.sub.20.5 mm and a cylindrical height of L.sub.2, wherein 0.05 mmL.sub.21.25 mm; a guide die having an optical fiber exit, the guide die disposed adjacent the cone-only coating die such that a wetted length (L.sub.5) between the optical fiber exit of the guide die and the entrance of the cone-only coating die is from 1 mm to 5 mm; and a holder for holding the cone-only coating die and the guide die in a fixed relationship defining a coating chamber between the guide die and the cone-only coating die, the coating chamber having an inner radius L.sub.6 from the optical fiber axis to an inner wall of the holder that is from 3 mm to 10 mm.

A method is disclosed of making a coated optical fiber. The method may involve drawing a preform through a furnace to create a fiber having a desired diameter and cross sectional shape. The fiber is then drawn through a slurry, wherein the slurry includes elements including at least one of metallic elements, alloy elements or dielectric elements, and the slurry wets an outer surface of the fiber. As the fiber is drawn through the slurry, it is then drawn through a forming die to impart a wet coating having a desired thickness on an outer surface of the fiber. The wet fiber is then drawn through an oven or ovens configured to heat the wet coating sufficiently to produce a consolidated surface coating on the fiber as the fiber exits the oven or ovens.

A method is disclosed of making a coated optical fiber. The method may involve drawing a preform through a furnace to create a fiber having a desired diameter and cross sectional shape. The fiber is then drawn through a slurry, wherein the slurry includes elements including at least one of metallic elements, alloy elements or dielectric elements, and the slurry wets an outer surface of the fiber. As the fiber is drawn through the slurry, it is then drawn through a forming die to impart a wet coating having a desired thickness on an outer surface of the fiber. The wet fiber is then drawn through an oven or ovens configured to heat the wet coating sufficiently to produce a consolidated surface coating on the fiber as the fiber exits the oven or ovens.

An optical fiber manufacturing method includes: coating an outer periphery of a bare optical fiber with a resin before curing by a coating device; and curing the resin with a coating curing device. The following equations are satisfied: tsin >T1 tan and =tan.sup.1 (d/L), where T1 is a tension in the upstream of the coating device, t is the shear force applied to the bare optical fiber by the resin, d is the design maximum value of a deviation amount of an entry position of the bare optical fiber into the resin in the coating device with respect to the center axis of the die hole of the coating device, and L is the contact length between the resin and the bare optical fiber in the coating device along the center axis.

A method of manufacturing an optical fiber wire includes applying ultraviolet curable resin onto the outer periphery of a traveling optical fiber, cooling the ultraviolet curable resin applied to the optical fiber using first cooled inert gas, and curing the ultraviolet curable resin by radiating ultraviolet rays on the ultraviolet curable resin that is cooled by the first cooled inert gas through an ultraviolet transparent tube.

A method of manufacturing an optical fiber wire includes applying ultraviolet curable resin onto the outer periphery of a traveling optical fiber, cooling the ultraviolet curable resin applied to the optical fiber using first cooled inert gas, and curing the ultraviolet curable resin by radiating ultraviolet rays on the ultraviolet curable resin that is cooled by the first cooled inert gas through an ultraviolet transparent tube.

Coated optical fibers and uses of such fibers as sensors in high temperature and/or high pressure environments. The coated optical fiber has improved sensing properties at elevated pressure and/or temperature, such as enhanced acoustic sensitivity and/or a reduced loss in acoustic sensitivity. The use of the coated optical fibers in various sensing applications that require operation under elevated pressure and/or temperature, such as, acoustic sensors for various geological, security, military, aerospace, marine, and oil and gas applications are also provided.

An optical communication cable includes a jacket having an interior surface that defines a cable jacket internal cross-sectional area and a plurality of optical fibers, wherein less than 60% of the cable jacket internal cross-sectional area is occupied by the cross-sectional area of the plurality of optical fibers. A scaffolding structure is provided adjacent to and supporting the jacket such that when the jacket is subjected to a burn and melts, the melted jacket material bonds to the scaffolding structure rather than sloughing off.

An optical communication cable includes a jacket having an interior surface that defines a cable jacket internal cross-sectional area and a plurality of optical fibers, wherein less than 60% of the cable jacket internal cross-sectional area is occupied by the cross-sectional area of the plurality of optical fibers. A scaffolding structure is provided adjacent to and supporting the jacket such that when the jacket is subjected to a burn and melts, the melted jacket material bonds to the scaffolding structure rather than sloughing off.