A furnace system includes a muffle defining a furnace cavity. A lower heater is coupled to the muffle and is configured to create a hot zone within the furnace cavity having a temperature of about 1900° C. or greater. An upper muffle extension is positioned above the muffle and defines a handle cavity. A downfeed handle is positioned within the handle cavity such that a gap is defined between an outer surface of the downfeed handle and an inner surface of the upper muffle extension. An upper heater is thermally coupled to the upper muffle extension and configured to heat the gap. A gas screen is positioned in the upper muffle extension and is configured to inject a process gas into the handle cavity.

A furnace system includes a muffle defining a furnace cavity. A lower heater is coupled to the muffle and is configured to create a hot zone within the furnace cavity having a temperature of about 1900° C. or greater. An upper muffle extension is positioned above the muffle and defines a handle cavity. A downfeed handle is positioned within the handle cavity such that a gap is defined between an outer surface of the downfeed handle and an inner surface of the upper muffle extension. An upper heater is thermally coupled to the upper muffle extension and configured to heat the gap. A gas screen is positioned in the upper muffle extension and is configured to inject a process gas into the handle cavity.

A variable seal for shielding from contaminants both an object to be heated in, and the heating element of, a high-temperature furnace. The seal has a first support ring and a second support ring separated by a distance. One or more components control the distance between the two support rings. A high-temperature fabric cylinder is attached to the support rings, is located where the object enters or exits the furnace, and surrounds at least a portion of the object. A mechanism engages the approximate center of the fabric cylinder to close the fabric cylinder as the one or more components decrease the distance between the two support rings and to open the fabric cylinder as the one or more components increase the distance between the two support rings, whereby the fabric cylinder continuously contacts the circumference of the object regardless of the diameter of the object.

A system for precoating a preform for drawing optical fiber including a diameter sensor to determine a diameter of pulled optical fiber, a cooling system to cool the optical fiber once it is pulled from a furnace, a coating system to apply a coating to the optical fiber once it has cooled and an ultra-violet lamp to cure the coating.

A system for precoating a preform for drawing optical fiber including a diameter sensor to determine a diameter of pulled optical fiber, a cooling system to cool the optical fiber once it is pulled from a furnace, a coating system to apply a coating to the optical fiber once it has cooled and an ultra-violet lamp to cure the coating.

A system for precoating a preform for drawing optical fiber including a diameter sensor to determine a diameter of pulled optical fiber, a cooling system to cool the optical fiber once it is pulled from a furnace, a coating system to apply a coating to the optical fiber once it has cooled and an ultra-violet lamp to cure the coating.

A system for precoating a preform for drawing optical fiber including a diameter sensor to determine a diameter of pulled optical fiber, a cooling system to cool the optical fiber once it is pulled from a furnace, a coating system to apply a coating to the optical fiber once it has cooled and an ultra-violet lamp to cure the coating.

A sensor system to provide data for use to control manufacture of an optical fiber in microgravity including a diameter sensor to monitor a diameter of a fiber drawn from a preform material, a tension sensor to monitor tension of the fiber as the fiber is pulled from the preform material to a storage device and a controller in communication with at least one of the diameter sensor and the tension sensor to evaluate sensor data to determine at least one of a speed and rate at which the fiber is pulled from the preform material.

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 preform manufacturing apparatus comprising a seal member, wherein the seal member is attached to a flange portion formed in an open portion of a reaction chamber into which a burner is inserted, the seal member includes a first sheet that is flexible and includes an open portion that is smaller than an outer diameter of the burner, through which the burner is inserted; a second sheet having the same thickness as the first sheet and including an open portion that is larger than an outer diameter of the first sheet; and two third sheets that each include an open portion that is larger than the outer diameter of the burner and smaller than the outer diameter of the first sheet, the second sheet is arranged in the same plane as the first sheet, and the first and second sheets are sandwiched by the two third sheets.