Fig. 1. Fiber Bragg grating hydrophone single sensing element

Fig. 2. Interference principle diagram of fiber Bragg grating hydrophone

Fig. 3. Diagram of high sensitivity Rayleigh scattering segment. (a) Starting point; (b) end point

Fig. 4. Schematic diagram of starting and end points of highly sensitive Rayleigh scattering segment

Fig. 5. Parasitic interference model simulation results. (a) Demodulation results in presence of parasitic interference induced by Rayleigh scattering; (b) cumulative probability distribution of link noise signal size ;(c) variation curve of noise power spectral level with the number of high-sensitivity Rayleigh scattering segments

Fig. 6. Experimental system setup diagram

Fig. 7. Demodulation results. (a) Four polarization channel light intensity sequences; (b) four polarization channel spectrograms; (c) four polarization channels demodulation results; (d) spectral density levels after polarization synthesis

Fig. 8. Wet end of experimental system. (a) Experimental diagram; (b) location of highly sensitive Rayleigh scattering segments in system

Fig. 9. Spectra after adding 1000 Hz, 10 V link interference. (a) a=100 m; (b) a=150 m

Fig. 10. Parasitic interference intensity in demodulated signals in presence of different locations and different frequency link interference. (a) 500 Hz; (b) 800 Hz; (c) 1000 Hz; (d) 1300 Hz; (e) 1500 Hz; (f) 1800 Hz; (g) 2000 Hz

Fig. 11. Number of highly sensitive Rayleigh scattering segments between link interference and dry end

Fig. 12. Cumulative probability distribution of link interference when link interference at different locations