20Gb/s Optical Soliton Data Transmission over 70km using Distributed Fiber Raman Amplifiers

Optical amplification is indispensable for optical soliton transmission to compensate for an inherent transmission fiber-loss[1]. Two kinds of amplification technique has been proposed: distributed amplification[2] and localized amplification[3]. The former offers much longer amplification spacing than the latter, because the former’s gain is distributed almost constantly along the fiber, while the latter’s gain is located locally, which leads to radiating dispersive waves[3]. In this paper, we report 20Gb/s optical soliton data transmission over a total distance of 70km utilizing two Raman amplifiers for fiber-loss compensation. The transmission distance corresponds to 19 soliton periods with our experimental parameters, and this value of 19 soliton periods is larger than any previously reported optical soliton data transmission. Raman gain as high as 10dB with forward and backward pumping by 160mW laser diodes was obtained by using a high Δn dispersion-shifted single-mode fiber as the transmission line. This fiber also has the advantage of transmitting optical solitons with relatively small input peak powers.