Fig. 1. Brillouin scattering in optical fibers

Fig. 2. Forward transmitted and backscattered powers versus input power^［23］

Fig. 3. The process of signal processing in STFT

Fig. 4. Optical circuit demodulation device used in the experiment

Fig. 5. Along-fiber Brillouin peak intensity distribution

Fig. 6. Denoised along-fiber Brillouin peak intensity distribution

Fig. 7. First derivative curve obtained after fitting

Fig. 8. Second derivative curve obtained after fitting

Fig. 9. BFS at room temperature

Fig. 10. The process of automatically identifying the stimulated position when the pulse width is 50 ns

Fig. 11. The process of automatically identifying the excited position at a frequency of 10 kHz

Fig. 12. The process of automatically identifying the stimulated position of a 1009 m optical fiber

Fig. 13. The process of automatically identifying the stimulated position in the heating experiment

Fig. 14. BFS diagram of heating experiment