CONTROLE DYNAMIQUE DE PERTE DE PUISSANCE DANS UNE FIBRE OPTIQUE PAR CONTRAPROPAGATION D'UN CANAL DE SUPERVISION

The device has a detection module (5) comprising an electronic circuit (7) that delivers primary information representing optical power loss of supervision signal in optical fiber. A comparator (8) in the module delivers secondary information representing power loss variation, to a variable optical attenuator (9) to reduce, increase, or maintain the attenuation level of the attenuator based on the secondary information state. The variable optical attenuator (9) attenuates the power of the supervision signal before the signal is extracted by a demultiplexer (6) of the detection module from the optical fiber. The supervision signal is injected into the optical fiber by a supervision module (3). The comparator delivers the secondary information by comparing the primary information with a value representing the nominal optical power loss in the optical fiber. An independent claim is also included for a process for dynamic measurement of power loss in an optical transmission line.