Experimental results on repeaterless 4× 622Mb/s × 200km
2. 5Gb/s× 200km and 4. 354Gb/s (1× 2. 488Gb/s+3 × 622Mb/s) × 160km conventional singlemode fiber transmission systems are reported in this paper. Results on another 4. 354Gb/s × 200km transmission with one repeater is also presented. Optical output from EDFA power booster is higher than 4dBm per channel (4 × 622Mb/s system)and 11dBm (2. 5Gb/s system)
respectively
while their frequency stability is better than 6 × 10-6 and 4.1× 10-6. Receiver sensitvity at the input of EDFA preamplifier reaches - 46. 8dBm (622Mb/s
NRZ 223 -1 PRBS)and - 39. sdBm (2. 5Gb/s
NRZ 223 -1 PRBS). Bit-error rate of various channels is better than 4 × 10 12