Effects of SBS and Rayleigh scattering in densely-spaced bidirectional transmission using Raman amplification

Summary form only given. We demonstrate 10 Gb/s bidirectional transmission over an 80-km dispersion compensated SMF fiber link using bidirectionally pumped Raman amplification. We measure the Rayleigh and SBS degrading effects that occur for channel spacings less than 25 GHz for different Raman gains and input signal levels. No penalty is seen for channel spacings 25 GHz and larger. We show that for gains up to 17 dB the Rayleigh degradation decreases with gain. And in order to avoid the SBS penalty at 12.5 GHz spacing, the highest signal power inside the fiber should be designed to be less than the SBS threshold. In this case, transmission with less than a 2 dB power penalty can be achieved at 12.5 GHz spacing.