Specialty Optical Fibers Handbook

capillary waves (Fig. 15.7). These standing waves are excited by fluctuation of

the parameters of the process, such as the fiber-drawing speed, diameter, po-

sition, and so on. The depth of the cavities can be about 5 mm. Thus, this effect

limits the minimum possible thickness of a continuously applied metal layer onto

a fiber.

The presence of cavities makes the strength and fatigue of a metal-coated fiber

sensitive to the atmosphere over the metallizer, because the cavities are filled with

Figure 15.6 Interior of a metal coating contacting with a fiber. (Part of the metal coating was

sliced by a knife.)

Moving fiber

Unperturbed

meniscus

Cavity

Figure