Error Rate Floor Research Articles

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

Using a cleaved-coupled-cavity (C3) ridge guide laser which oscillates in a single longitudinal mode at 1.55 μm 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.

IMPATT-Diode Power Amplifiers for Digital Communication Systems

lMPATT-diode amplifiers with a power output of 1.0 W have been developed for use in an 11-GHz digital radio. Two types of amplifiers, a multistage reflection amplifier and a hybrid amplifier containing an injection-locked oscillator stage, have been evaluated by measuring the bit error rate degradation due to the amplifier. System test data show that the stable amplifier introduces little or no errors while the injection-locked oscillator (ILO) often introduces an error-rate floor.