Effect of initial curvature on low temperature microbending in optical fibers.

The study contains an analytical evaluation of the thermally induced microbending in dual-coated optical fibers, with an emphasis on the effect of the initial local curvatures. Our analysis has shown that these curvatures could cause appreciable additional deflections of the fiber at even moderately low temperatures, thereby resulting in the added transmission losses. The developed formulas are simple, easy-to-use and clearly indicate the role of various factors affecting the prebuckling behavior of the fiber. They also indicate what could be done to bring down the temperature induced curvatures and the resulting added transmission losses. Some recommendations for the selection of the thicknesses and material characteristics are presented. The numerical examples are executed for silicone/nylon coated systems, studied experimentally by Katsuyama and Yabuta. The theoretical prediction agrees well with the experimental data.