A 150 km Undersea Repeaterless Lightwave Transmission Link Operating at a 1.55 Micron Wavelength

The data and power transmission system described herein spans some 150 km between a shore site and an off-shore floating platform. The full-duplex data link will be one of the first operational applications of undersea lightwave technology anywhere in the world when it is turned over for service early in 1985. At a line rate of 3.088 megabaud it achieves this distance without undersea electronics by taking advantage of leading-edge laser, photo detector, fiber, and undersea cable technology in the 1.55 micron wavelength range. Additionally, over half a kW of power is delivered to the platform over the power conductor of the undersea cable, which also functions as a strength member and protection for the glass fibers. A rather unique scheme for sea-bottom to surface-platform cabling and attachment is also described.