Fiber strength assurance for deep-submarine optical-fiber cable using the proof-testing method

Fiber strength assurance using the proof-testing method is studied for a submarine optical-fiber cable for use up to depths of 8000 m. An appropriate proof-test strain for the cable, which has been developed for low elongation under the tensile strains experienced during laying and recovery, is shown to be 2.2 percent for the depth of 8000 m. For a cable to be deployed over a range of depths, possible proof-test level design philosophies are discussed with fiber economics as a parameter.