NEW TEST METHOD FOR DETERMINING THE WATER SENSITIVITY OF OPTICAL FIBER COATINGS

Low water sensitivity optical fiber coatings protect optical wave-guides from the damaging effects of moisture on static fatigue. The standard test method used to determine the water sensitivity of UV-curable optical fiber coatings does not give a realistic measure of a coating's water sensitivity. The maximum absorption can be reached before 24 h, the extraction continues even after 24 h, and sample pre- and postconditioning greatly influence the results. In the proposed new test method, a number of weight change measurements of samples immersed in water are made as a function of time. Because of the dynamic nature of the test, a more realistic understanding of the water sensitivity of optical fiber coatings is obtained. The effect of different pre- and postconditioning environments is investigated and a recommendation for the best method is made.