Scale expansion of transparent photonic transport network based on distributed Raman amplification

We examine the impact of distributed Raman amplification (DRA) on the cascadability of transparent photonic transport system nodes and reveal its advantage in terms of amplified spontaneous emission noise. A 10 Gb/s/spl times/16 channel recirculating loop experiment with DRA demonstrates that a transparent network over 610 km (8 nodes) can be constructed even for a relatively large node loss of 20 dB.