Abstract: A method and corresponding apparatus for processing optical fiber include directing light from a directed light source toward an optical fiber on a fiber draw. A fiber core of the optical fiber is heated, using at least the light from the directed light source, to a fiber core temperature within a glass transformation temperature range of the fiber core. The method can be used to reduce fictive temperature of the fiber core, with Rayleigh scattering being reduced, leading to lower attenuation losses in the fiber core.

Abstract: In one embodiment, an apparatus for screen testing an optical fiber includes a fiber conveyance pathway, a capstan having an outer circumference and a fiber contact region extending around the outer circumference, the fiber contact region having a durometer hardness of less than or equal to about 40 Shore A, where the capstan is positioned adjacent to the fiber conveyance pathway such that when the optical fiber is directed over the fiber conveyance pathway, the optical fiber engages with the fiber contact region, and a pinch belt positioned adjacent to the fiber conveyance pathway such that the fiber conveyance pathway extends between the pinch belt and the fiber contact region, where the pinch belt is engagable with the fiber contact region such that, when the optical fiber is directed over the fiber conveyance pathway, the optical fiber is impinged between the pinch belt and the fiber contact region.

Abstract: An optical fiber with low fictive temperature along with a system and method for making the optical fiber are provided. The system includes a reheating stage that heats the fiber along the process pathway to a temperature sufficient to lower the fictive temperature of the fiber by relaxing the glass structure and/or driving the glass toward a more nearly equilibrium state. The fiber is drawn from a preform, conveyed along a process pathway, cooled and subsequently reheated to increase the time of exposure of the fiber to temperatures conducive to lowering the fictive temperature of the fiber. The process pathway may include multiple reheating stages as well as one or more fiber-turning devices.

Abstract: In one embodiment, an apparatus for screen testing an optical fiber includes a fiber conveyance pathway, a capstan having an outer circumference and a fiber contact region extending around the outer circumference, the fiber contact region having a durometer hardness of less than or equal to about 40 Shore A, where the capstan is positioned adjacent to the fiber conveyance pathway such that when the optical fiber is directed over the fiber conveyance pathway, the optical fiber engages with the fiber contact region, and a pinch belt positioned adjacent to the fiber conveyance pathway such that the fiber conveyance pathway extends between the pinch belt and the fiber contact region, where the pinch belt is engageable with the fiber contact region such that, when the optical fiber is directed over the fiber conveyance pathway, the optical fiber is impinged between the pinch belt and the fiber contact region.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: An optical fiber with low attenuation is provided. The fiber is produced under conditions that reduce fictive temperature. Processing includes maintaining the fiber at temperatures at or near the glass transition temperature (Tg) for an extended period of time. For silica-based fibers, the preferred temperatures are temperatures between 1000° C. and 1700° C. The extended residence times are achieved in a continuous fiber manufacturing process by increasing the path length of the fiber through a processing region maintained at temperatures between 1000° C. and 1700° C. The increased path length is achieved by including one or more fluid bearing devices in the processing region. The extended residence time in the processing region allows the structure of the glass fiber to relax more completely and to more closely approach the equilibrium state. The more relaxed glass structure leads to a lower fictive temperature and provides fibers with lower attenuation.

Abstract: In one embodiment, an apparatus for screen testing an optical fiber includes a fiber conveyance pathway, a capstan having an outer circumference and a fiber contact region extending around the outer circumference, the fiber contact region having a durometer hardness of less than or equal to about 40 Shore A, where the capstan is positioned adjacent to the fiber conveyance pathway such that when the optical fiber is directed over the fiber conveyance pathway, the optical fiber engages with the fiber contact region, and a pinch belt positioned adjacent to the fiber conveyance pathway such that the fiber conveyance pathway extends between the pinch belt and the fiber contact region, where the pinch belt is engagable with the fiber contact region such that, when the optical fiber is directed over the fiber conveyance pathway, the optical fiber is impinged between the pinch belt and the fiber contact region.

Abstract: An optical fiber production system and method are provided for producing optical fiber. An optical fiber is drawn from a preform in a furnace and passes through a treatment device under a controlled reduced pressure or partial vacuum in the range of 0.01 to 0.8 atm. The treatment device cools the bare optical fiber as it cools to a temperature range of at least 1,600° C. to 1,300° C. A non-contact fiber centering device is located near an exit of the treatment device to provide linear centering of the optical fiber as it exits the treatment device.

Abstract: A method and device for continuously testing the tensile strength of an optical fiber, wherein the incoming optical fiber is wrapped at least partially around a payout capstan, to an intermediate payout pulley, at least partially around the intermediate payout pulley, and back to the payout capstan. The optical fiber is then wound from the payout capstan to a tensile testing measurement component, and then to an uptake capstan. The optical fiber is wrapped at least partially around the uptake capstan, to an intermediate uptake pulley, at least partially around the intermediate uptake pulley, and back to the uptake capstan. The payout capstan and uptake capstan are operated at a desired rotational speed to continuously advance the optical fiber for tensile strength testing.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: An optical fiber production system and method are provided for producing optical fiber. An optical fiber is drawn from a preform in a furnace and passes through a treatment device under a reduced pressure in the range of 0.01 to 0.80 atm. The treatment device cools the bare optical fiber as it cools to a temperature in the range of at least 1,600° C. to 1,300° C. A non-contact fiber centering device is located near an exit of the treatment device to provide centering of the optical fiber as it exits the treatment device.

Abstract: A method and device for continuously testing the tensile strength of an optical fiber, wherein the incoming optical fiber is wrapped at least partially around a payout capstan, to an intermediate payout pulley, at least partially around the intermediate payout pulley, and back to the payout capstan. The optical fiber is then wound from the payout capstan to a tensile testing measurement component, and then to an uptake capstan. The optical fiber is wrapped at least partially around the uptake capstan, to an intermediate uptake pulley, at least partially around the intermediate uptake pulley, and back to the uptake capstan. The payout capstan and uptake capstan are operated at a desired rotational speed to continuously advance the optical fiber for tensile strength testing.

Abstract: A method for producing a coated optical fiber may include drawing an optical fiber from a draw furnace along a first vertical pathway. The optical fiber may then be routed through at least one fluid bearing thereby redirecting the optical fiber along a second vertical pathway. Thereafter, a thermoplastic coating may be applied to the optical fiber with a thermoplastic coating system. The optical fiber may then be wound onto a fiber storage spool with a fiber take-up system. The fiber take-up system may be space apart from the thermoplastic coating system such that the thermoplastic coating may be cooled before the optical fiber is wound onto the fiber storage spool.

Abstract: Methods for producing a coated optical fiber may include drawing an optical fiber from a draw furnace along a first pathway and redirecting the optical fiber along a second, different pathway which is non-parallel with the first pathway. The optical fiber may be coated as it travels along the second pathway.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: A method for forming an optical fiber includes drawing the optical fiber from a glass supply and treating the fiber by maintaining the optical fiber in a treatment zone wherein the fiber is cooled at a specified cooling rate. The optical fiber treatment reduces the tendency of the optical fiber to increase in attenuation due to Rayleigh scattering, and/or over time following formation of the optical fiber due to heat aging. Methods for producing optical fibers along nonlinear paths incorporating fluid bearings are also provided thereby allowing for increased vertical space for the fiber treatment zone.

Abstract: An optical fiber production system and method are provided for producing optical fiber. An optical fiber is drawn from a preform in a furnace and passes through a treatment device under a controlled reduced pressure or partial vacuum in the range of 0.01 to 0.8 atm. The treatment device cools the bare optical fiber as it cools to a temperature range of at least 1,600° C. to 1,300° C. A non-contact fiber centering device is located near an exit of the treatment device to provide linear centering of the optical fiber as it exits the treatment device.

Abstract: An optical fiber production system and method are provided for producing optical fiber. An optical fiber is drawn from a preform in a furnace and passes through a treatment device under a reduced pressure in the range of 0.01 to 0.80 atm. The treatment device cools the bare optical fiber as it cools to a temperature in the range of at least 1,600° C. to 1,300° C. A non-contact fiber centering device is located near an exit of the treatment device to provide centering of the optical fiber as it exits the treatment device.