PUMP-POWER-INDEPENDENT DOUBLE SLOPE-ASSISTED DISTRIBUTED AND FAST BRILLOUIN FIBER-OPTIC SENSOR

摘要

A method of stimulated Brillouin scattering is proposed in which both slopes of the BGS spectrum are probed to achieve immunity to pump power variations. Suitably applied, the technique can maintain all the benefits of the known Slope-Assisted-BOTDA technique, while using the same setup but at the cost of halving the sampling speed. the method may include: obtaining a reference Brillouin gain spectrum (BGS) representative of steady state or average conditions in various locations of the optical fiber along its length; generating, based on the reference BGS, a probe wave being a complex waveform comprising a first and second set of waveforms, each set having waveforms tailored to match an opposite slope of the reference BGS, at the various locations; performing stimulated Brillouin scattering at the various locations by applying a pump pulse wave to the probe wave; and deducing the local Brillouin frequency shift (BFS) at the various locations.

主权项

1. A method for determining local variations in strain and/or temperature along an optical fiber, the method comprising:
obtaining a reference Brillouin gain spectrum (BGS) representative of steady state or average conditions in various locations of the optical fiber along its length; generating, based on the reference BGS, a probe wave being a complex waveform comprising a first and second set of waveforms, each set having waveforms tailored to match an opposite slope of the reference BGS, at said various locations; performing stimulated Brillouin scattering at said various locations by applying a pump pulse wave to said probe wave; and deducing the local Brillouin frequency shift (BFS) at said various locations.