FIELD: electric communication. SUBSTANCE: bi-directional optical amplifier includes unidirectional optical amplification unit characterized by single band of lengths of waves of amplification, two input and output ports for at least two optical signals with opposite directions of propagation having first and second lengths of waves correspondingly and differing one from another but included in same band of lengths of waves of amplification, two first and two second optical communication elements selective to lengths of waves of optical element that includes first bandwidth that contains above-mentioned first length of wave and second bandwidth including second length of wave correspondingly. Mentioned-above first and second bandwidths do not overlap mutually. Amplification unit is placed between opposite units of optical bridge circuit in which units of mentioned-above first and second selective optical communication elements are located and which are positioned in symmetry with regard to amplification unit and ports of input and output of mentioned optical signals. EFFECT: simplified design of amplifier. 11 cl, 16 dwg
