A method of manufacturing an optical fiber of the invention includes: preparing a direction changer; drawing a bare optical fiber from an optical fiber preform, thereby forming the bare optical fiber; providing a coated layer made of a resin on a periphery of the bare optical fiber; obtaining an optical fiber by curing the coated layer; changing a direction of the bare optical fiber by use of the direction changer; measuring a drawing velocity of the optical fiber; and adjusting a length of the bare optical fiber from a drawing unit to a coating unit by controlling a position of the direction changer based on a measurement value of the drawing velocity, the drawing unit forming the bare optical fiber, the coating unit providing the coated layer on the periphery of the bare optical fiber.

An optical fiber production method includes: drawing an optical fiber from an optical fiber preform in a drawing furnace; cooling the optical fiber in an annealing furnace; and delivering the optical fiber into the annealing furnace, and controlling a temperature difference between a temperature of the optical fiber and a fictive temperature of glass forming a core included in the optical fiber to be higher than 20 C. and lower than 100 C.

A non-contact direction changer includes: a guide groove that guides an optical fiber and changes a direction of advancement of the optical fiber from a first direction to a second direction; a bottom ejection opening at a bottom of the guide groove; and one or more side ejection openings on at least one of opposite side surfaces of the guide groove. A fluid is ejected into the guide groove through the bottom ejection opening. A fluid is ejected into the guide groove through the one or more side ejection openings.

An optical fiber manufacturing apparatus includes a heating furnace configured to heat and melt an optical fiber preform; a pulling mechanism configured to adjust an outer diameter of a glass optical fiber by drawing out the glass optical fiber from the optical fiber preform melted through the heating by the heating furnace, and to draw the glass optical fiber that has been adjusted in outer diameter; a coating mechanism configured to apply a predetermined resin on an outer circumference of the glass optical fiber that has been adjusted in outer diameter; and a transport mechanism configured to returnably retract the coating mechanism from a passage route of the glass optical fiber.

A control device which is used in a manufacturing apparatus of an optical fiber, the manufacturing apparatus including a drawing unit and a coating unit. The control device includes: one or a plurality of non-contact holding portions which hold the bare optical fiber at any position between the drawing unit and the coating unit; a position detection unit; and a control unit which controls a flow rate of a fluid introduced into the non-contact holding portion on the basis of the floating position detected by the position detection unit. The non-contact holding portion comprises a guide groove. The control unit detects the floating position of the bare optical fiber at at least one of the non-contact holding portions, compares the detected floating position with a predetermined reference floating position, and controls a flow rate of the fluid introduced into the non-contact holding portions.

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.

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 control device which is used in a manufacturing apparatus of an optical fiber, the manufacturing apparatus including: a drawing unit; a coating unit; and a curing unit which cures the coating layer. The control device includes: one or a plurality of direction changing devices which change a direction of the bare optical fiber at any position between the drawing unit and the coating unit; a position detection unit which detects a position of the bare optical fiber in the direction changing device; an outer diameter measurement unit which measures an outer diameter of the bare optical fiber; and a control unit which controls a flow rate of a fluid introduced into the direction changing device on the basis of the position of the bare optical fiber measured by the position detection unit and the outer diameter of the bare optical fiber measured by the outer diameter measurement unit.

An optical fiber manufacturing method includes: drawing an optical fiber preform to form a bare optical fiber; cooling the bare optical fiber by a non-contact direction changer; adjusting a temperature of the bare optical fiber in a temperature adjusting unit disposed downstream of the non-contact direction changer and upstream of a coating unit; disposing, in the coating unit, an uncured coating layer that comprises a resin precursor on an outer periphery of the bare optical fiber; and curing the uncured coating layer in a curing unit.

Aspects of the embodiments include an optical fiber formed in a low gravity environment. The optical fiber can be used in airframe applications for missile defense, oil-field applications for down-well laser applications, optical communications, and other applications. The optical fiber can include a fluoride composition, such ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN), and can be characterized by an insertion loss in a range from 13 dB/1000 km to 120 dB/1000 km. The optical fiber can deliver optical energy with low insertion loss at the desired power and wavelength for the various applications.