Bidirectional hybrid fiber amplifiers in a recycling-pump mechanism

In this paper, a bidirectional hybrid fiber amplifiers is proposed and experimentally demonstrated. The hybrid amplifiers include a C-band erbium-doped fiber amplifier (EDFA) and an L-band Raman fiber amplifier (RFA). A single-wavelength pump source at 1495 nm is pumped shared to both the EDFA and the RFA. Under the pump power of 500 mW, the average gains are about 11.3 dB for the C band EDFA and 10.0 dB for the L band RFA, respectively, with a launched signal power of -10 dBm per channel. For 50 km and 75 km bidirectional transmission, the power penalties are less than 0.38 dB and 0.88 dB, respectively, as compared to their unidirectional transmissions.