A hybrid fiber amplifier with 36.9-dBm output power and 70-dB gain

A high-power and extremely high-gain hybrid fiber amplifier with the good noise figure (NF) performance is developed and investigated. It comprises a two-stage erbium-doped fiber amplifier as a pre-amplifier and an erbium/ytterbium co-doped double-cladding fiber amplifier as a post-amplifier. At the signal wavelength of 1550 nm, the signal gains of up to 70 dB and the maximum output power of 36.9 dBm or 4.90 W have been demonstrated when the total pump power is 12.5 W. We have obtained that the NFs of the hybrid fiber amplifier is varying from 6.12 to 7.72 dB for the 1550-nm signal wavelength with the input power range from −21 to +6 dBm.