Field demonstration of distributed Raman amplification with 3.8-dB Q-improvement for 5 x 120-km transmission

The benefits of distributed Raman amplification are demonstrated in a buried cabled field fiber. The performance improvement of 3.8 dB was achieved in a 5/spl times/120-km 10-Gb/s transmission experiment using 650-mW Raman amplification in each span without apparent damage to the fiber plant. The field results are compared to a similar laboratory experiment using a fusion-spliced fiber to evaluate the effect of finite optical reflections from nonfusion splices in the field fiber.