Aspects of the embodiments are directed to systems and methods for forming an optical fiber in a low gravity environment, and an optical fiber formed in a low gravity environment. The system can include a preform holder configured to secure a preform; a heating element secured to a heating element stage and residing adjacent the preform holder; a heating element stage motor configured to move the heating element stage; a tension sensor; a spool; a spool tension motor coupled to the spool and configured to rotate the spool; and a control system communicably coupled to the heating element stage motor and the spool tension motor and configured to control the movement of the heating element stage based on a rotational speed of the spool. 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.

A method for determining the temperature of a strand comprises disposing the strand along a background radiator of known temperature. Receiving the strand using a spatially resolving thermal imaging sensor in front of the background radiator while the strand is being disposed along its longitudinal axis. Forming an integral across a measuring value area, the integral configured to detect a complete strand portion located in front of the background radiator of the thermal imaging sensor. deducing the temperature of the strand by comparing the formed integral with a reference value

An optical fiber preform includes: a columnar portion having an approximately constant radius of r; and a taper portion located adjacent to the columnar portion in a lengthwise direction and having a radius decreasing along the lengthwise direction. The taper portion includes: a first taper portion including a portion having a radius varying between 0.9r and 0.6r; and a second taper portion including a portion having a radius varying between 0.4r and 0.15r. A diameter of the first taper portion in the portion having the radius varying between 0.9r and 0.6r decreases so as to form a maximum angle 1 between 40 degrees and 60 degrees with respect to the columnar portion, a diameter of the second taper portion in the portion having the radius varying between 0.4r and 0.15r decreases so as to form an average angle 2 between 5 degrees and 30 degrees with respect to a central axis in the lengthwise direction, and a volume of the taper portion is smaller than or equal to 45% of a volume of a column having a same outer diameter as a maximum outer diameter of the taper portion and having a same length as the taper portion.

Embodiments are directed to systems and methods for material processing in a low gravity environment, and an optical fiber formed in a low gravity environment. The system established the control of both the temperature and the temperature gradients to compensate for the effects of microgravity environment. The control of the neck-down region during the fiber draw in microgravity through the controlled temperature distribution in the work volume delivers steady-state process for microgravity manufacturing.

Methods, systems, and device implementing slow cooling of reduced cladding diameter optical fibers are described. An optical fiber manufacturing system may draw optical fibers based on heating and extruding, via a draw furnace, optically transmissive material. The optical fiber manufacturing system may include a cooling device positioned after the draw furnace and configured to cool the optical fibers. Cooling the optical fibers with the cooling device may include applying one or more gases with low thermal conductivity to the optical fibers. Applying the one or more gases to the optical fibers may reduce a rate at which the optical fibers are cooled. For example, the cooling device may be configured to transition the optical fibers from a relatively pliable state associated with exiting the furnace to a relatively hardened state at a relatively slow rate. The optical fibers may have a cladding diameter less than or equal to 115 m.

Provided is a method for manufacturing an optical fiber glass preform in which a refractive index distribution is stable in a longitudinal direction of the glass preform. A method for manufacturing an optical fiber glass preform includes: depositing a porous glass preform by a vapor phase method; and sintering the porous glass preform in a heating region, when sintering the porous glass preform, the porous glass preform being inserted into a vessel of a sintering furnace, and an inside of the vessel being heated with a heater installed on an outer periphery of the vessel to form the heating region. The sintering is started after a surface temperature difference of the porous glass preform in a longitudinal direction is made 50 C. or lower.