The use of coherent techniques in lightwave communications can provide improved sensitivities over those that have been obtained using direct detection receivers[l]. For this reason coherent techniques may be useful for long-haul, high-bit-rate systems. We have explored this possibility in a system operating at 2 Gb/s, and achieved 170 km transmission. This represents a record bit rate, as well as bit-rate-distance product (340 Gb km/s), for a coherent lightwave system. It is also a record distance for any system operating at 2 Gb/s.
© 1987 Optical Society of AmericaPDF Article