Accurate cross-sectional stress profiling of optical fibers

A novel technique for determining two-dimensional, cross-sectional stress distributions in optical fibers and fiber-based devices is presented. Use of the Brace-Köhler compensator technique and a polarization microscope for the measurement of retardation due to stress-induced birefringence is described, along with the tomographic reconstruction process for the determination of stress. Measurements are performed on Corning SMF-28 fiber in an unperturbed section, a section near a cleaved end-face, and a section exposed to CO2 laser radiation. Cross-sectional stress distributions are presented. Stress relaxation is quantified in the cleaved fiber and the fiber exposed to CO2 laser radiation.