Improvements in submarine cable for optical fibers to telecom- munications

摘要

A submarine cable with optical fibers which prevents damage to the fibers due to water pressure without the use of an external armor. The cable has a central core with a strand which provides the cable tensile strength and which is surrounded and contacted by a layer of plastic material having helical grooves which receive the optical fibers which may have a protective covering. The layer of plastic material is surrounded by a thin metal sheath which, in turn, is closely surrounded by a layer of plastic material. The grooves and any spaces radially inwardly of the sheath, such as the spaces between the wires of the strands, are filled with a practically incompressible fluid, such as a grease or jelly. If the optical fiber protective layer is a tube loosely receiving the optical fiber, or optical fibers, the space within the tube not filled by optical fibers is filled with a substantially incompressible fluid. A further layer of plastic material may be interposed between the metal sheath and the plastic material layer of the core and may at least partially extend into the grooves.