Abstract

In optical fiber technology, it is important to characterize mechanical properties precisely in addition to transmission properties. Especially fiber elongation is one of the important mechanical characteristics in evaluating the fatigue phenomenon and predicting the mechanical lifetime. However the conventional tensile tests based on the mechanical systems are not always sufficient ones for the precise measurement of breaking elongation, due to the following reasons;

(1) There are deviations from linearity in the dependence of glass elongation on stress.^[1]

(2) It is difficult to correct the contributions of catenary in the long fiber span during tensile test.

(3) It is difficult to correct the stress relaxation in jacketing materials.