Effects of silica nanoparticle addition to the secondary coating of dual-coated optical fibers

The mechanical and optical properties of dual-coated optical fibers with silica nanoparticles added to the secondary (outer) coating have been investigated. Incorporation of silica nanoparticles in the secondary coating is shown to enhance the resistance of optical fibers to fatigue and zero stress aging. In contrast to the properties of single-coated fibers containing the silica additive, this beneficial effect is obtained without degrading the tensile strength. Pretreatment of the nanoparticles to improve their dispersion in the coating is also investigated. Two dispersants studied do not significantly improve dispersion and result in reduced efficiency of the mechanical reliability enhancing effect. However, improving the mechanical mixing process does produce coatings with well-dispersed nanoparticles; as a consequence a significantly reduced optical loss and a more dramatic improvement of mechanical reliability result.