A system for drawing optical fiber in microgravity including a sealed housing to prevent infiltration of at least humidity and filled with a dry environment, a preform holder located within the sealed housing to hold preform material, a furnace located within the sealed housing to receive the preform material from the preform holder and to heat the preform material from which the optical fiber is pulled, a feed system to move the preform material from the preform holder to the furnace, a drawing mechanism located within the sealed housing to pull the optical fiber from the preform material within the furnace, a diameter monitor located within the sealed housing to measure a diameter of the optical fiber and a fiber collection mechanism located within the sealed housing to gather and store the optical fiber.

A method of processing an optical fiber includes drawing the optical fiber from a heated glass source, reheating the optical fiber, and cooling the optical fiber under vacuum at a cooling rate less than the cooling rate of the optical fiber in air at 25° C. and 1 atm. Cooling the optical fiber under vacuum is conducted after reheating the optical fiber. Cooling the optical fiber under vacuum reduces the rate of heat transfer from the optical fiber, which may enable further relaxation of the glass and reduction in the fictive temperature of the optical fiber. A system for processing an optical fiber includes a furnace containing a fiber preform, a first positioner, a reheating device, and a treatment device downstream of the reheating device, the treatment device operable to cool the optical fiber under vacuum to reduce the rate of heat transfer from the optical fiber.

A method of winding an optical fiber includes winding the optical fiber using a bobbin that includes: a body portion having two end portions; and a pair of flanges, respectively disposed at the end portions in an axial direction of the body portion. An inner surface of each of the flanges is inclined toward an outer side in the axial direction and toward a radial outer side. The method further includes guiding the optical fiber to the bobbin using a final pulley. The bobbin and the final pulley reciprocate relative to each other in the axial direction at a traverse speed V (mm/sec) such that 0.0050≤θ (rad)≤0.1000, where θ is a delay angle, θ=arctan (V/L), and L (mm) is a distance from a winding position of the optical fiber at the bobbin to the final pulley in a radial direction.

An optical fiber draw system and method of operating thereof. The method includes positioning a downfeed handle for supporting an optical fiber preform within a furnace such that the downfeed handle is movable within the furnace. The method further includes operating one or more heating elements to thermally heat at least a portion of an upper muffle extension disposed within the furnace, the one or more heating elements being moveable with the downfeed handle.

A system for processing an optical fiber includes: a draw furnace, said draw furnace containing an optical fiber preform; a bare optical fiber drawn from said optical fiber preform, said bare optical fiber extending from said draw furnace along a process pathway; and a slow cooling device operatively coupled to and downstream from said draw furnace, said slow cooling device exposing said bare optical fiber to a slow cooling device process temperature in the range from 1000° C. to 1400° C., wherein the bare optical fiber passes through the slow cooling device at least two times.

A method of manufacturing an optical fiber, the method including drawing a bare optical fiber from an optical fiber preform along a draw pathway. The method further includes during the drawing step, moving a first fluid bearing from a first position to a second position, the first position being removed from the draw pathway and the second position being disposed in the draw pathway such that the movement of the first fluid bearing to the second position causes at least a first portion of the draw pathway to change direction.

An optical fiber bundle manufacturing apparatus includes: a winding member; a guide member movable in a direction parallel to a rotary axis, the guide member being configured to guide an optical fiber wire to any one of first winding positions, a converging winding position and second winding positions; and a processor configured to perform processing to move the guide member such that a first branching portion branching into p branches, a converging portion converging the first branching portion branching into p branches into one, a second branching portion branching into q branches, and a connecting portion connecting the first branching portion and the second branching portion are formed in this order by the optical fiber wire.

An apparatus for tensioning and threading an optical fiber includes a first roller, a second roller, a belt that wraps around the first and second rollers, and a third roller. The belt may be in direct physical contact with the first and second rollers. The third roller may be movable between an engaged and a disengaged configuration relative to the belt. Alternatively, the first roller, second roller, and belt may be movable between the engaged and the disengaged configuration relative to the third roller. Actuation from the disengaged to the engaged configuration captures an optical fiber between the third roller and the belt.

Methods of manufacturing multi-mode optical fiber, and multi-mode optical fiber produced thereby, are disclosed. According to embodiments, a method for forming an optical fiber may include heating a multi-mode optical fiber preform and applying a draw tension to a root of the multi-mode optical fiber preform on a long axis of the multi-mode optical fiber preform thereby drawing a multi-mode optical fiber from the root of the multi-mode optical fiber preform. The draw tension may be modulated while the multi-mode optical fiber is drawn from the root of the multi-mode optical fiber preform. Modulating the draw tension introduces stress perturbations in the multi-mode optical fiber and corresponding refractive index perturbations in a core of the multi-mode optical fiber.

A process for cleaning particulate matter from the interior of a muffle of an optical fiber draw furnace includes propagating sound waves through the interior of the muffle at a frequency of from about 75 Hz to about 5000 Hz and an intensity of from about 110 dB to about 160 dB.