Dual-pump sweep-free stimulated Brillouin optical distributed sensing method and device

The present invention concerns a Brillouin optical distributed sensing method, comprising steps of: (i) providing a first and a second optical pulsed pump wave (20, 23) and an optical probe wave comprising at least one probe spectral component (26), (ii) detecting a stimulated Brillouin scattering signal resulting from the interactions in a sensing optical fiber of the optical probe wave with the first and the second optical pulsed pump waves (20, 23), (iii) spectrally arranging the first and the second optical pulsed pump waves (20, 23) and the optical probe wave so that the optical probe wave comprises a probe spectral component (26) located within the Stokes Brillouin spectrum (21) of the first optical pulsed pump wave (20) and a probe spectral component (26) located within the anti-Stokes Brillouin spectrum (24) of the second optical pulsed pump wave (23), (iv) deducing the Brillouin frequency (22, 25) of the Brillouin spectra (21, 24) from the stimulated Brillouin scattering signal. The present invention concerns also a device for implementing the method.