Specialty Optical Fibers Handbook

Laboratory testing that has been accelerated by using aggressive environments

(high temperature, high water activity) has shown an additional strength reduc-

tion mechanism in addition to fatigue. This ‘‘aging’’ phenomenon must be

considered because of its potential negative impact on reliability.

24.3.3 Aging

In the study of the strength and reliability of silica light guides, testing is often

carried out under extreme conditions to accelerate the degradation and, thus,

hopefully allow prediction out to longer times/lifetimes. When this was done

early in the study of silica light-guide fibers, an effect that had not really been

known earlier was discovered in both aging and fatigue [40, 41]. If fiber is held

for some time under no stress and subsequently ...