Effect of initial curvature on low temperature microbending in optical fibers

An analytical evaluation of the thermally induced microbending in dual-coated optical fibers is presented, with an emphasis on the effect of the initial local curvatures. The analysis has shown that these curvatures could cause appreciable additional deflections of the glass fiber even at moderately low temperatures, thereby resulting in added transmission losses. The developed formulas are considered simple, easy-to-use, and to indicate clearly the role of various factors affecting the prebuckling behavior of fiber. They also indicate what could be done to bring down, if necessary, 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, which were studied experimentally by Y. Katsuyama et al. (1983). The theoretical prediction agrees well with the experimental observations