Multi-point acoustic impedance sensing based on enhanced forward stimulated Brillouin scattering

In recent years, the research on acoustic impedance sensing based on Forward Stimulated Brillouin Scattering (FSBS) has made great progress. Here, we propose a method of enhance excitation in multi-point frequency division multiplexing acoustic impedance detection based on FSBS. The external acoustic impedance of different fibers can be distinguished by specific frequency peaks in fibers with different diameters based on the fiber resonance center frequency determined by FSBS. Pulse-modulated light is used to make the pulsed light carry a specific resonance center frequency, so as to directionally enhance the excitation of the corresponding FSBS mode and achieve high-energy transmission. This experiment verifies that the sensor size of 0.6 m can complete the acoustic impedance sensing of multiple locations.