Multi-stage optical amplifier

A three-stage optical amplifier is disclosed having a first pre-amplifying stage for receiving an optical signal to be amplified and having a length of erbium doped fibre and a pump for providing energy to the erbium doped fibre. A second-stage is optically coupled to receive the optical signal from the first-stage after the optical signal has been pre-amplified. The second-stage a Raman amplifier has a length of standard or DCF optical fibre and a Raman pump for providing energy to the length of optical fibre for further amplifying the pre-amplified signal propagating therethrough and for controlling tilt of the amplified signal. A third stage EDFA for further amplifying the signal amplified by the Raman amplifier. Conveniently, the Raman stage is useful for both amplifying and providing tilt control.