Fig. 1. P-FBG interferometric hydrophone. (a) Schematic diagram; (b) structure of hydrophone unit design; (c) encapsulated unit (up) and unit structure (down)

Fig. 2. Four-element P-FBG hydrophone array. (a) Hydrophone array without melting points; (b) acoustics pressure sensitivity of each unit

Fig. 3. Noise suppression in P-FBG hydrophone array. (a) Suppression of crosstalk; (b) schematic of Doppler noise

Fig. 4. Principle and results of polarization diversity receiving. (a) Schematic diagram; (b) demodulated signal of single-channel signal after 0° polarizer; (c) demodulated signal after polarization diversity receiving

Fig. 5. 32-element P-FBG hydrophone array. (a) Partial hydrophone array with 20-mm diameter; (b) 32-element FBG towed hydrophone array; (c) P-FBG hydrophone array system