A furnace heats fiberoptic preform to the melting point in newly constructed draw towers at SpecTran Specialty Optics (Avon, CT). Below the furnace, the actual fiber is being pulled down the tower by a capstan at the base; the fiber runs to a take-up unit where it is rolled onto a spool. In the region above the capstan, various coatings can be applied using either ultraviolet or thermal curing processes.
The newly constructed draw tower is enclosed in an environmentally controlled room to maintain consistent and clean draw. A technician follows the computer-controlled process on a monitor. With feedback from dual-plane laser-diameter gauges in the towers, draw conditions can be adjusted to precisely control fiber diameter. The equipment was designed for high flexibility and can produce fiber with diameters ranging from 50 to 2000 µm and with a variety of coatings.