Method and apparatus for communicating status in a lightwave communication system employing optical amplifiers

摘要

A repeater node for an optical transmission system provides amplification of optical signals and uses a modulated pump signal to transfer status information about the repeater node to a control system via an optical supervisory signal. The pump signal supplied by a pump source to an optical amplifier is modulated with one or more tones that are indicative of status in the repeater node. In a transmission fiber coupled to the output of the optical amplifier, the modulation of the pump signal is transferred to the supervisory signal of the optical transmission system as a result of Raman effect. More specifically, the pump wavelength and the supervisory signal wavelength are such that the modulated tone on the shorter wavelength pump signal is transferred to the longer wavelength supervisory signal. The tone can then be extracted from the supervisory signal and processed at another node in the system: