Field evaluation result on hermetically coated optical fiber cables for practical application

A field trial was carried out to evaluate the overall performance of hermetically coated fibers. Three cables containing a large volume of hermetic and nonhermetic fibers were manufactured, and their initial strengths and n values were measured. The cables were installed in duct and aerial routes. Eight optical links were constructed, including dispersion-shifted and normal single-mode fibers, by splicing the installed fibers. Statistical data on optical loss and splice loss were obtained in the trial. The measured results demonstrated that the hermetically coated fiber cables had much higher fatigue resistance than conventional fiber cables, and no weak portion was found even for 500 hermetic fiber samples selected from a large volume of trial fibers. The transmission characteristics were found to be equivalent and low-loss splicing was achieved in the field