Mechanical characteristics of quartz optical fibers

The interdependence of the strength of coated quartz fibers and the coefficient of strength variation is considered. The research was conducted on monomode quartz fibers with different protective-strengthening coatings, obtained from MCVD stock. Initially, the tensile strength along the entire length of a single fiber (1140 m) was measured sequentially every meter using a Zwick type tensile testing machine (with a loaded section length of 0.3 m and a loading rate of 100 mm/minute). The average values of the strength and corresponding strength variation coefficients were calculated for the sequential fragmentations of several types from the 1140 values for 25, 50, 100 and 200 measurements. It was established that a reduction of the degree of polymerization of the fiber coating led to a linear growth in the strength variation coefficient, and to a reduction in the average strength. When choosing a fiber design or creating new technology for producing them, the fiber strength may conveniently be evaluated on samples with an identical strength variation coefficient.