A method of manufacturing a multimode optical fiber includes specifying a peak wavelength .sub.P for the multimode optical fiber. The peak wavelength .sub.P corresponds to a wavelength at which the multimode optical fiber has a maximum bandwidth. The multimode optical fiber comprises a core and a cladding surrounding and directly adjacent to the core. The core has a radius r.sub.1 and a maximum relative refractive index .sub.1,MAX>0. The cladding comprises a depressed-index region having a minimum relative refractive index .sub.3,MIN<0 and a volume v. A draw tension T for the multimode optical fiber is selected based on a correlation relating peak wavelength .sub.P to draw tension T, the correlation comprising a correlation constant. The correlation constant K is a function of at least one of .sub.1,MAX, r.sub.1, v, .sub.3,MIN, and .sub.P. The multimode optical fiber is drawn from a preform at the draw tension T.

A preform material including a starter tip to facilitate an initial fiber draw from the preform within a furnace, wherein the tip comprises a vacuum-sealed tip to receive a plastic grip which attached to an end of a preform.

A drawing system for polygonal optical fiber is provided, comprising: a clamping moving device, a furnace, a protective layer coating device, at least a protective layer drying system, and a fiber take-up device, all arranged from top to bottom; the clamping moving device clamping a polygonal preform rod and slowly moving the preform rod into the furnace; a polygonal optical fiber extracted from bottom of the furnace passing sequentially through the protective layer coating device, the protective layer drying system, and finally the fiber take-up device controlling drawing speed of the polygonal optical fiber, characterized in that: at least two optical fiber micrometers being disposed between the furnace and the protective layer coating device, and the two optical fiber micrometer respectively measuring two outer diameters of different sizes of the polygonal optical fiber; the fiber take-up device adjusting the drawing speed according to measurement results of the optical fiber micrometers.

A method of manufacturing a tuned optical fiber includes providing a first preform from a set of like preforms each having substantially the same refractive index profile, including amount of axial variation relative to a target refractive index profile. The method includes drawing a reference optical fiber from the first preform and measuring a variation in an optical or physical property as a function of axial position. The method also includes drawing from a second preform from the set of like preforms the tuned optical fiber. The drawing includes using a time-varying tension that reduces the amount of variation of the optical or physical property of interest. The time-varying tension is defined by an amount of axial stress imparted to the tuned fiber needed to alter the refractive index profile and the at least one optical or physical property based on a stress-optic effect.

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.

The disclosure provides a method of manufacturing a multicore optical fiber comprising a plurality of cores and a common cladding covering each of the plurality of cores and having a non-circular cross-sectional shape capable of passive alignment. The method includes providing an optical fiber preform having a cross-sectional shape delimited by a line obtained by replacing a part of a circumference with one chord or two chords parallel to each other, and applying a drawing tension to one end of the optical fiber preform to draw a multicore optical fiber. An aspect ratio x of the cladding defined by a ratio of a radius of a circle defining the circumference to a distance from the center of the circle to the chord and a drawing tension y are set so that the common cladding has a depression at the center of a plane corresponding to the one or each of the two chords.

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.

An optical fiber includes an outer diameter less than 220 m, a glass fiber that includes a glass core and a glass cladding, a primary coating, and a secondary coating. The glass cladding surrounds and is in direct contact with the glass core. The primary coating surrounds and is in direct contact with the glass fiber. The primary coating can have a Young's modulus less than 0.5 MPa and a thickness less than 30.0 m. The secondary coating surrounds and is in direct contact with the primary coating. The secondary coating can have a thickness less than 27.5 m. A pullout force of the optical fiber can be less than a predetermined threshold when in an as-drawn state. The pullout force may increase by less than a factor of 2.0 upon aging the primary and secondary coatings on the glass fiber for at least 60 days.

A light diffusing optical fiber includes a core, a cladding surrounding the core, an outer surface, and a plurality of scattering structures positioned within the core, the cladding, or both the core and the cladding. The plurality of scattering structures are configured to scatter guided light towards the outer surface, such that light including a wavelength of from about 450 nm to about 650 nm diffusing through the outer surface along a diffusion length of the light diffusing optical fiber includes a spectral attenuation percent relative range of about 15% or less.

A high-density optical fiber ribbon is formed by two or more cladding-strengthened glass optical fibers each having an outer surface and that do not individually include a protective polymer coating. A common protective coating substantially surrounds the outer surfaces of the two or more cladding-strengthened glass optical fibers so that the common protective coating is common to the two or more cladding-strengthened glass optical fibers. A fiber ribbon cable is formed by adding a cover assembly to the fiber ribbon. A fiber ribbon interconnect is formed adding one or more optical connectors to the fiber ribbon or fiber ribbon cable. Optical data transmission systems that employ the fiber ribbon to optically connect to a photonic device are also disclosed. Methods of forming the cladding-strengthened glass optical fibers and the high-density optical fiber ribbons are also disclosed.