Optical communication system

摘要

An optical communication system comprising: a first transmitter; a first receiver; a first primary guided optical path (1) having a protected portion; a first secondary guided optical path (2); at least an optical amplifier; a modulation device, up-line from the said protected portion of the said first primary guided optical path (1), for transmitting a first overmodulation frequency along the said protected portion; a detection device, down-line from the said protected portion of the said first primary guided optical path (1), for detecting the presence or absence of the said first overmodulation frequency; and an operating device, down-line from the said protected portion of the said first primary guided optical path (1), connected operationally to the said first secondary guided optical path (2); the said first transmitter sending at least one optical signal (300) at least along the said first primary guided optical path (1) and the said first receiver receiving the said at least one optical signal (300), in which, when the said detection device detects the absence of the said first overmodulation frequency in the said protected portion of the said first primary guided optical path (1), the said operating device enables the said optical signal (300) to be propagated along the said first secondary guided optical path (2) up to the said first receiver. <IMAGE>