Km. Guild et al., UNREPEATERED TRANSMISSION OVER 415 KM AT 2.5GBIT S WITH RAMAN GAIN AND +26.5DBM LAUNCH POWER/, Electronics Letters, 32(22), 1996, pp. 2087-2088
2.5 Gbit/s transmission is demonstrated over a mixed fibre system with
out using remote optically pumped amplifiers (ROPAs). The use of NRZ d
ata with clock pre-chirp, stimulated Brillouin scattering (SBS) suppre
ssion and dispersion compensation enables a +26.5 dBm signal to be lau
nched into fibre. A 980 nm pumped preamplifier with a 3.5 dB noise fig
ure and additional Raman gain at the receiver realises a system length
of 392 km with an effective sensitivity of -45.2 dBm. When the system
fibre length is increased to 415 km, an error rate is demonstrated wh
ich if forward error correction (FEC) were used would give error free
transmission.