Study of the mechanical behavior of the optical fiber by a mark-tracking method

LARMAUR Equipe Verres ERL CNRS 6274, PPT - Bâtiment 10B - Campus de Beaulieu, 35042 Rennes Cedex, France

Abstract

The mark-tracking method was used in the uniaxial tensile test to determine the elastic properties of optical fibers. The mark-tracking method is based on the followup of two markers on the specimen with the help of an image processing technique. It allows us to determine the true strain with respect to the small strains assumption (e 1%) or the finite strains (e>1%) without any impact of the rigid solid movement neither pulley fiber sliding on the measured strain. Optical fibers used in this study are commercial Verrillon single mode silica fibers, 125 µm in diameter with a two layers 62.5 µm thick epoxy-acrylate polymer coating. Both as-received optical fiber and stripped fiber were subjected to the uniaxial tensile test and the cantilever beam bending test. The stripped fiber Young’s modulus results under both tests were found to be very similar. Thus, the mark-tracking method is adaptable to the tensile test of optical fibers and the elastic behavior of both as-received optical fiber and stripped fiber is found to be linear. Their Young’s modulus are 22GPa and 83GPa, respectively. These results revealed that those coatings are playing a mechanical role in the fiber elongation.