UNREPEATERED TRANSMISSION OVER 415 KM AT 2.5GBIT S WITH RAMAN GAIN AND +26.5DBM LAUNCH POWER/

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.