A system, amplifier and method are provided for amplifying an optical
signal in an optical communications system where spans between amplifiers
may vary. The system includes a Raman amplifier variable gain portion and
an EDFA gain portion. The amount of Raman amplifier gain is chosen to
trade off accumulation of noise with accumulation of multi-path
interference. This variable Raman gain is used to equalize the loss of
each span so that the amount of optical power supplied at the input of
the EDFA gain portion is substantially constant throughout the system.