Strength of optical silica fibers measured in liquid nitrogen

The strength of an optical silica fiber with a polymer coating is measured in liquid nitrogen, and the strength of the coating is measured using the three-point bending technique. The average strength of the silica fiber is found to be 14 GPa and that of the coating is 0.43 GPa. The fracture of the coating during tests in liquid nitrogen is shown to increase the dispersion of the strengths of the optical silica fiber as compared to tests in air.