Field demonstration of coherent transmission system with diode-pumped erbium doped fibre amplifiers

Reports a field demonstration of 622 Mbit/s DPSK and FSK coherent transmission over 200 km of installed single mode fibre. Diode-pumped erbium doped fibre amplifiers were used as both power amplifiers and repeaters. System loss budgets of more than 68 dB were achieved with an intermediate amplifier repeater gain of 16.5 dB. Both systems incorporated fully automated endless polarisation control.