Hi koll,
I have read since the optical gain in a Raman amplifier is distributed over a long span of optical fiber, the optical pump is used at the end of a length of fiber to provide optical gain that increases towards the end of the fiber. So a Raman amplifier can be combined with an EDFA booster (to act as an in-line amplifier) or inline amplifier to produce a more uniform power along the length of fiber. I have seen EDFA being used in all stages. Also, hybrid optical amplifiers are deigned and used.
Regards