Hybrid discrete Raman/EDFA design for broadband optical amplification in metro WDM systems

A novel design of a broadband discrete Raman/EDFA hybrid amplifier is proposed. A broadband signal of 84 channels across 75 nm is experimentally amplified and the gain contribution of each amplifier stage is shown. The amplifier consists of a discrete Raman amplifier using a DCF fibre pumped at three 14×× nm wavelengths, which is followed by a 1480 nm pumped erbium doped fibre. An average gain of 15.4 dB and gain flatness of ± 1.7 dB with no gain equalising elements is achieved.