Design of double-coated optical fibers to minimize long-term hydrostatic-pressure-induced microbending losses

Abstract

The design of double-coated optical fibers to minimize long-term hydrostatic-pressure-induced microbending losses is investigated. Microbending loss in these fibers is dominated by compressive radial stress at the interface between the glass fiber and the primary coating, which is a function of the material properties of the polymeric coatings and their thickness. To minimize long-term hydrostatic-pressure-induced microbending losses, one should decrease the Young's modulus and Poisson ratio of the primary coating but increase the radius, Young's modulus, Poisson ratio, and relaxation time of the secondary coating. Alternatively, the radius and relaxation time of the primary coating have their optimum values.