FIELD: fiber-optic communication lines. SUBSTANCE: amplifier has first and second decouplers; first amplifier unit incorporating first wavelength-selection coupler; first optical pumping device and first optical fiber connected to first coupler and doped with erbium to amplify optical input signal using forced radiation due to first pumping source; absorption unit; second wavelength- selection coupler with input port connected to first amplifier unit, as well as first and second output ports; absorber one of whose leads is connected to first output port of second coupler; second optical transmitting fiber connected to second output port of second coupler; third wavelength-selection coupler incorporating first and second input ports connected, respectively, to absorber and to second transmitting fiber, as well as output port designed for coupling signals introduced through first and second input ports and also for transmitting coupled signals through mentioned port; second amplifier unit used for amplifying optical output signal coming from absorbing unit and incorporating second optical pumping source. Absorber is, essentially, erbium- doped fiber that functions to absorb optical signal of 1530 nm wavelength coming from first output port of second coupler. EFFECT: enhanced gain, reduced noise. 3 cl, 4 dwg
