DISTRIBUTED FIBRE OPTIC SENSING SYSTEM AND METHOD BASED ON STIMULATED BRILLOUIN SCATTERING.

摘要

The invention relates to a distributed fibre optic (3) sensing system and method based on stimulated Brillouin scattering, consisting in: separating the two signals forming the probe signal, and obtaining the difference between the stimulated amplification band (8) and attenuation band (9), or vice versa. This produces a signal of greater amplitude than with single-band detection. In this way, the signal-to-noise ratio (dynamic range) in the signal from the sensor is improved and the range is increased, while measurement uncertainty is reduced. In addition, the common noise present in the two bands of the probe signal is eliminated and, when a balanced detector is being used for detection, the saturation characteristics of the detector are improved, allowing much larger signal amplitudes to be obtained than are conventionally obtained.