The optical cables Submarines are extremely vulnerable to seawater corrosion due to long-term immersion in high-concentration seawater. Furthermore, hydrogen molecules will diffuse into the fiber's glass material, increasing fiber loss. Therefore, submarine fiber optic cables must not only prevent hydrogen from forming internally but also from penetrating the cable from the outside. Currently, the structure of a submarine fiber optic cable consists of helically wrapping the optical fiber after one or two coatings in the center, with a reinforcing element (made of steel wire) wrapped around it.
Put up a physical map of the seabed, which is more intuitive:
A submarine fiber optic cable is somewhat similar to an oil pipeline; in fact, the biggest difference between a submarine fiber optic cable and a terrestrial fiber optic cable is its "armor protection." The reason so many layers of protection are required is because the underwater environment submarine fiber optic cables face is extremely complex and harsh. The first threat is seawater corrosion. The outer polymer layer of the submarine fiber optic cable is designed to prevent the reaction between seawater and the reinforced steel cable to produce hydrogen. Even if the outer layer is corroded, the inner copper tubing, paraffin, and carbonic acid resin will prevent hydrogen from damaging the optical fiber. Infiltration of hydrogen molecules will lead to increased attenuation of the fiber optic transmission. In addition to seawater corrosion, submarine fiber optic cables are also subject to underwater pressure, natural disasters (earthquakes, tsunamis, etc.), and human factors (fishermen's rescue operations). Without enhanced armor protection, submarine fiber optic cables cannot operate reliably for extended periods.
However, even with such strict protection, the submarine fiber optic cable still cannot be used permanently and its lifespan is generally only 25 years.
Post time: Feb-16-2023
