Curing shrinkage effects of UV-curable materials on fiber loss characteristics

The curing shrinkage effect in the radial direction of ultraviolet UV-curable coating on fiber-loss characteristics is investigated theoretically and experimentally. It is shown that curing shrinkage causes lateral forces to the fiber and leads to microbending loss increases at low temperatures. A model for pressure caused by curing shrinkage in the radial direction is discussed. According to this model, the radial pressure to the optical fiber in the coating can be estimated by measuring the fiber pulling force from the coated optical fiber. Based on the agreement of theoretical and experimental results, the allowable range of curing shrinkage percentages of primary and secondary coatings to prevent fiber-loss increase is obtained. Design strategies to prevent fiber loss increases at low temperatures are described