Hydrogen Generation In Sl Cable Due To Manufacture And Service Life

In optical fiber communications systems, the presence of excess hydrogen in a cable may increase optical loss and thereby impair transmission. This study focuses on the mechanisms of hydrogen generation during the manufacture of an undersea optical fiber cable and the amount of hydrogen accumulated in a cable during its service life. Hydrogen can be introduced into the fiber environment by a variety of mechanisms: thermal degradation of polymers, outgassing of other constituent materials, and aqueous attack of cable materials by moisture. To assess the amount of hydrogen generated due to polymer degradation and outgassing, during manufacture, gas samples extracted from cables were analyzed for hydrogen concentration. Also, the amount of moisture entrapped in a cable during manufacture was studied. The likelihood of water condensation in a cable at the lowest operational cable temperature was analyzed and determined to be very low. In addition to hydrogen produced during manufacture, cable storage and at-sea damage will also generate hydrogen in a cable.