1 Gbit/s transmission experiment over 101 km of single-mode fibre using a 1.55 ¿m ridge guide C3 laser

Using a cleaved-coupled-cavity (C3) ridge guide laser which oscillates in a single longitudinal mode at 1.55 ¿m wavelength, we report the first lightwave transmission experiment exploying single-frequency lasers at speeds above 500 Mbit/s. We have achieved digital transmission with a bit-error rate of 2 × 10¿10 at 1.0 Gbit/s over 101 km of single-mode fibre. This represents a record for the length of unrepeatered optical transmission for bit rates greater than 500 Mbit/s. Evidence for an error-rate floor, presumably due to residual partition noise, is observed. No such floor was observed in an 84 km¿1 Gbit/s experiment using the same C3 laser.