Study of the Drawing Process for Optical Fibers

摘要

Optical fibers are produced by heating a silica rod and pulling on the rod to produce a thin fiber. This process involves several interacting effects, especially the temperature dependent viscosity of the rod, and the shape of the rod in the transition zone. In this paper the equations describing this process are studied by means of a perturbation analysis using as the perturbation parameter the ratio of the rod to the length of the furnace. The silica rod is usually doped so that it will have special optical properties and it is important to know the concentration of the dopant in the final fiber. Simple equations for the significant terms in the perturbation series are obtained for all quantities of interest. A simple formula is obtained which expresses the radius of the fiber in terms of the initial radius of the rod, the drawing force and other important parameters. (Author)