Device for measuring and dynamically compensating variations in power loss in an optical transmission line with a supervisory channel, and an associated method

An optical device for measuring and dynamically compensating power loss variations in an optical transmission line, the device comprising:

• injector means (4) adapted to inject supervisory signals having a chosen optical power into said line, which includes an optical fiber (2) having an entry end (E) adapted to receive primary optical signals and said supervisory optical signals and an exit end (S) adapted to deliver said primary signals and said supervisory signals;
• detector means (5) adapted:
• to extract said supervisory signals at the exit end (S) of the fiber (2) to determine their optical power and to deduce therefrom and from said chosen optical power primary information representative of the optical power loss of the supervisory signals in the fiber (2), and
• to compare said primary information and a value representative of a nominal power loss in the fiber to deliver secondary information representative of a variation in the power loss in said optical fiber;
• which device is characterized in that it further comprises control means (11) coupled to said detector means (5) and to the exit end (S) of the fiber (2) and adapted, if a variation in the power loss of the supervisory signals in the fiber is detected, to modify the power of the primary signals delivered by the exit end of the fiber (2) as a function of said detected power loss variation.