The Design of Hermetically Double-Coated Optical Fibers to Minimize Hydrostatic Pressure-Induced Stresses

The design of hermetically double-coated optical fibers to minimize hydrostatic pressure-induced stresses is investigated. Several stresses are important in the hermetically double-coated optical fibers, and they would produce the excess bending losses or the failure of hermetic coatings. These stresses can be minimized by appropriately selecting material's properties of hermetic coatings and their thicknesses. The hydrostatic pressure-induced stresses in optical fibers with some selected metallic coatings are also considered. The results show that chromium has the best performance in the minimization of hydrostatic pressure-induced stresses. However, lead and indium are poor materials.