Several methods of fabricating optical waveguides which are currently being studied will be described. This will include a discussion of the doped deposited silica techniques being used in the preparation of commercially available low-loss fibers, and other techniques presently being developed, such as double crucible melting techniques, plastic-clad glass fibers, and rod-in-tube techniques. The impact of the fabrication technique on such fiber performance parameters as peak refractive index difference, index gradients, dispersion, attenuation and durability will be explored. The economics of the various process will be superficially examined in terms of raw materials costs and availability, as well as their purity requirements.
|