cw Raman amplifier for soliton transmission

Summary form only given. The Raman amplifier has the attraction that the transmission fiber is its own amplifier and the first experiments with soliton transmission produced encouraging results, but the lack of inexpensive and reliable pump sources and the appearance of more efficient erbium-doped fiber amplifiers (EFDAs) put the Raman amplifier into the shadow. However the development of highly efficient fiber lasers with output power up to 1 W could have a significant impact on the application of the imaginary part of fiber nonlinearity (Raman gain) when and where the real part (the Kerr effect) is already in use. In this paper we demonstrate that the advances of modern fiber optics might result in a re-examination of the Raman amplifiers role in ultra-high bit rate transmission systems.