Device for measuring and/or dynamically controlling power loss in an optical transmission line and method therefor

摘要

A front end modulator (4) arranged upstream from an optical fiber end (E), modulates the amplitude of optical signal with a low-frequency modulation signal having modulation index inversely proportional to the input power of the optical signal. A back end detector (7) extracts information representing output amplitude of the modulation signal, and detects information representing power loss variation in fiber from the amplitude information. Independent claims are also included for the following: (1) an optical signal transmission installation; and (2) a method of measuring power loss in optical fiber.