Multifunction C+L band EDFA/RFA hybrid fiber amplifiers

We proposed and demonstrated a hybrid fiber amplifier. It is composed of a C-band erbium-doped fiber amplifier EDFA) and an L-band Raman fiber amplifier (RFA) using double-pass dispersion compensators in a loop-back scheme. Dispersion slope mismatch is compensated precisely for all C+L band channels by writing fiber Bragg gratings (FBGs) at appropriate locations. Gain variation among multiple channels can be reduced to ±0.2 dB. The pump efficiency is improved by recycling the residual pump power. Both the simulation results and experimental measurements are realized in this paper.