A Raman plus linear optical amplifier as an inline amplifier in a long-haul transmission of 16 channels × 10 Gbit/s over single-mode fiber of 1040 km

We have successfully demonstrated a long-haul transmission of 16 channels × 10 Gbit/s over single-mode fiber of 1040 km using combined Raman and linear optical amplifiers as inline amplifiers. All the span length used was 80 km (loss of 16 dB), but the span losses varied from 28 to 34 dB according to some additional loss elements, e.g., dispersion-compensating fiber and a variable optical attenuator. The measured Q-factors of the 16 channels after 1040 km (12.7-14.5 dB) were higher than the error-free threshold of the standard forward-error correction, which offers feasibility of the hybrid amplifiers including semiconductor optical amplifiers for the long-haul transmission.