Coherent lightwave transmission at 2 Gbit/s over 170 km of optical fibre using phase modulation

Abstract
We report coherent lightwave transmission at a data rate of 2Gbit/s over 170 km of optical fibre. Phase modulation is employed, and a bit error rate lower than 10-9 is achieved. The receiver sensitivity of –39.0 dBm 10-9 BER) is an improvement of 2.4 dB over the best previously published direct-detection result for non-return-to-zero transmission.