FIELD: fiber-optic communication systems, with optical amplifiers inclusive. SUBSTANCE: the device has an optical isolator comprising a Faraday rotator installed between two polarizers. Two light-emitting diodes are located outside each polarizer. Collimators are positioned between each light-emitting diode and the respective polarizer. A coupler is made on the light-detecting surface of the first polarizer. The first and second photodetectors are used for reception of the first and second beams respectively reflected from the coupler, coming out of the first and second light-emitting diodes respectively. The third and fourth light-emitting diodes are output ones. EFFECT: simplified design and enhanced efficiency due to the use of two light beams of one optical isolator. 5 cl, 4 dwg
