Epoxy-acrylate-coated fused silica fibers with tensile strengths ≳500 ksi (3.5 GN/m2) in 1-km gauge lengths

Abstract

Laser-drawn epoxy-acrylate-coated fused silica fibers (∼110 μm fiber diameter) have been produced with high and exceptionally uniform strength. When tested in 20-μm lengths, they show a single-moded Weibull distribution, (m∼25), a median tensile strength Sm of 750 ksi (5.25 GN/m2), and a coefficient of variation (ν) of about 0.04. Using the previously justified ’’weakest link’’ model, this predicts Sm∼600 ksi (4.2 GN/m2) for l-km gauge lengths. The measured strength of a 1680-m-long fiber (i.e., the minimum strength found in testing 84 20-m lengths) is 620 ksi (4.35 GN/m2). The capability of drawing kilometer lengths of fibers with strengths of this magnitude and uniformity is extremely important for the production of optical fiber cables.