An efficient method to produce fibers with outer diameter varying along the length

摘要

A digital control system to draw fibers varying along the length from standard preform had been developed. It is possible to obtain fibers with a necessary length dependence on the diameter with high accuracy. During the drawing process information about the current diameter is processed by digital control unit and compared with a calculated value. A control signal produced by the computer is passed to the drawing unit. Ada (ANSI-MIL-STD-1815A) has been choosen as programming language to develop the control system software. In particular the single mode fiber with chromatic dispersion decreasing along the length (DDF) had been fabricated. Such fibers are an attractive medium for optical signal processing and advanced communication systems. The DDF length may be in the range from several meters to several kilometers. The diameter deviation from the pre-arranged value is less than 0.2