Viscoelastic analysis of hydrostatic pressure induced optical effects in double-coated optical fibers

The microbending losses and refractive index changes of double-coated polymeric optical fibers induced by hydrostatic pressure are studied by viscoelastic analysis. The results obtained by using the Laplace transfer method, the linear viscoelastic–linear elastic correspondence principle, and the compatibility conditions of displacement at the interfaces are presented. It is presented that the results obtained by viscoelastic analysis can be reduced to those obtained by using elastic analysis. The materials of the polymer coatings should be properly selected in order to minimize microbending losses and refractive index changes. It will also be presented that microbending losses and refractive index changes decrease with a decrease in the Young’s modulus and Poisson’s ratio of the primary coating in conjunction with an increase in the elastic constants of the secondary coating.