Fig. 1. The schematic description of SBS process in WGM resonator

Fig. 2. The scheme of the experimental setup

Fig. 3. （a）The packaged resonator and the waveguide，（b）the packaged resonator sealed in a box with two fiber connectors

Fig. 4. （a）CaF₂ resonator with 12.6 mm diameter and 0.1 mm rim thickness，（b）simulation result of the eigenmode distribution，（c）transmission spectrum contains multi-mode resonance，（d）calculating the quality factor based on a selected resonance

Fig. 5. the result of SBS contains three Brillouin lights

Fig. 6. The result of cascaded SBS up to fifth-order