FIELD: amplification of optical signals and selective separation of desired-waveform signals. SUBSTANCE: amplifier has optical filter at its output lead for eliminating its inherent noise and is designed to tack and filter off wavelengths of transmitted optical signal using wavelength control unit for adjusting central wavelength of optical filter to that of transmitted optical signal upon determining wavelength of the latter. EFFECT: improved reliability of optical devices. 11 cl, 6 dwg
