Stimulated Brillouin scattering in multi-mode fiber for sensing applications

We present measurements and characterization of stimulated Brillouin scattering (SBS) in multi-mode fiber (MMF) in comparison with single-mode fiber (SMF). As can be expected, the threshold for SBS was measured to be much higher in MMF (105 mW) compared with SMF (15 mW). A difference of 525 MHz was observed in the SBS frequency shift between both types of fibers. An increase in the gain bandwidth, which was measured to be 17 MHz for MMF compared to 8 MHz in SMF and which is due to several modes present in the MMF. Temperature dependence of the frequency shift was also investigated and was shown to be the same (1 MHz/°C) for both types of fibers. Several applications are therefore proposed using SBS in multi-mode fiber.