Humidity Dependence of the Fatigue of High‐Strength Fused Silica Optical Fibers

Abstract

Strength and dynamic fatigue behavior of silica fibers has been measured as a function of ambient humidity. Bare and polymer-coated fibers were compared to determine the influence of the coating. The results verify earlier work that suggests the degradation reaction is approximately second order with respect to humidity. However, we verify this result using rigorous data analysis techniques and, unlike the earlier work, the result is shown to be independent of the form of the kinetic model for crack growth. Trends in the calculated fatigue parameters illustrate that a simple exponential crack growth law best describes the humidity data. No significant differences were found between coated and bare fibers, provided the coated fibers were properly equilibrated. A data analysis methodology is given for obtaining valid reaction orders independently of the crack growth law form.

Indentation deformation mechanism of isostatically compressed mixed alkali aluminosilicate glasses

“…In addition to chemical composition, the values of H V and CR are influenced by various parameters, such as the load applied during indentation [5,6], atmospheric conditions [7][8][9][10][11], processing conditions [12,13], and post-treatment [14]. Various post-treatment methods are currently being applied in the industry to prepare damage resistant glasses with improved values of H V and/or CR, such as chemical strengthening and thermal tempering.…”

The combined effect of temperature and humidity on the fatigue parameters and reliability of optical fiber

“…In particular the reaction order with respect to humidity was found to be two. 3 However, other coatings may have a significant effect on the fatigue kinetics so caution should be used before applying our results to other coating systems.…”

“…It has been shown previously that if this fiber is properly equilibrated with the test environment the coating will not perturb the reaction kinetics. 3 Therefore, for convenience only coated fibers are studied here. The equilibration periods utilized depended on the temperature of the test environment and ranged from overnight for the lower temperatures to one hour for the higher temperatures.…”

A study of the fracture mechanisms in pristine silica fibres utilising high speed imaging techniques

“…Two main factors determine the process of crack formation at room temperature; the level of atmospheric humidity and stress. The role of these two factors is believed to be somewhat different even though they use similar mathematical models [59]. Models which suggest that atmospheric humidity is responsible for crack growth assume that the chemical reaction of the silica with water molecules weakens the intermolecular bonds and works as a catalytic agent [56,60,61].…”