Patent ID: 8848284

Claim:
A bidirectional optical amplifier arranged to be passed through in one direction by a downstream optical signal and in an opposite direction by an upstream optical signal, comprising: a first optical circulator having three ports, a second optical circulator having three ports, a downstream unidirectional optical amplifier connected between a second port of the first optical circulator and a second port of the second optical circulator so as to define a downstream amplification path for the downstream optical signal, and an upstream unidirectional optical amplifier connected between a third port of the first optical circulator and a third port of the second optical circulator so as to define an upstream amplification path for the upstream optical signal, wherein the bidirectional optical amplifier further comprises a waveband separator to reject the wavelength component of the upstream optical signal, the waveband separator only being disposed in the downstream amplification path, the waveband separator being connected between the second port of the first optical circulator and an input of the downstream unidirectional optical amplifier.