Real-time fast and distributed measurement of a Brillouin-inhomogeneous fiber using tailored-frequency probe in slope-assisted BOTDA

Using a tailored-frequency probe, this paper presents a distributed slope-assisted BOTDA (SA-BOTDA) measurement of an optical fiber, bonded to a bent cantilever, where the fiber's static Brillouin Frequency Shift continuously varies along its length by an amount of the order of or larger than the Brillouin bandwidth. While standard SA-BOTDA methods, employing a fixed probe frequency, may suffer from distortions in measuring vibrations around this Brillouininhomogeneous static state, a tailored probe preserves the full dynamic range offered by the slope of Brillouin gain spectrum. The computerized measurement system is capable of real-time continuous monitoring of the strain, including averaging.