Repeaterless undersea lightwave systems

A repeaterless undersea lightwave system connects two terrestrial locations separated by the sea without the need for undersea regeneration of the optical signal. To achieve the longest span length possible, the system combines terrestrial terminals containing superior-performance optoelectronic devices with ultrareliable undersea cable technology. The lightwave technology used to achieve cost-effective, long-span repeaterless undersea lightwave systems is discussed. This includes undersea fiber and cable, lasers and receivers, and terminal equipment. The first application of this technology, Taiwan's Tainan to Peng-Hu system, is described. The possibilities for increasing the maximum attainable span length of high-capacity repeaterless undersea systems are examined. Key elements are higher-output transmitters, more sensitive receivers, and improved optical fibers