Specialty Optical Fibers Handbook

Kassahun and Viriyayuthakorn [75] described the improvements offered by

pressurized coating application, 40–80 N=cm

2

, towards bubble-free coatings on

fiber.

Paek and Schroeder [76] reported substantial improvement in high-speed

drawing up to 12 m/sec. Fibers were determined to have uniform 50-micron

coating thickness and concentricity along a 50-km length. The fibers survived a

proof test stress level of 0:7GN=m

2

(100,000 psi), and most survived stress levels

of twice that level. Draw speed rates of 0.7 and 10 m/sec were found to produce

single-mode fibers with identical optical properties.

Draw tower coating speeds ranged from 1 to 2 m/sec in the 1979–1981 time-

frame [71]. Improvements in optical glass technology began to yield larger

preforms, which ...