Simple BOTDA temperature sensor based on distributed Brillouin Phase-Shift measurements within a Sagnac interferometer

In this work we demonstrate an extremely simple BOTDA scheme capable of delivering distributed Brillouin Phase Shift measurements along an optical fiber. It is based on exploiting the non-reciprocity of the Stimulated Brillouin Scattering effect. This non-reciprocity is easily characterized by means of a suitably tuned Sagnac Interferometer. The technique is advantageous as, in comparison with previous methods, no complex modulation, no sharp filtering and no highbandwidth detection is needed. Theoretical and experimental proofs of the concept are given.European CommissionMinisterio de Economía y CompetitividadComunidad de MadridUniversidad de Alcal