Fig. 1. Principle diagram of uwFBG hydrophone array system based on Fizeau interference

Fig. 2. Schematic of arc-tangent demodulation algorithm

Fig. 3. Error curves of phase signal to be demodulated and demodulated phase signal

Fig. 4. Experimental setup of vibration liquid column method

Fig. 5. Time domain diagrams of underwater acoustic signal demodulated by uwFBG hydrophone with sensor's cavity length of 200 m when frequency of signal generator is 2, 10, 100, 500, 1000, 2000 Hz

Fig. 6. Frequency domain diagram of underwater acoustic signal demodulated by the uwFBG hydrophone with sensor's cavity length of 200 m when frequency of signal generator is 2, 10, 100, 500, 1000, 2000 Hz

Fig. 7. Variation of phase acoustic-pressure sensitivity of uwFBG hydrophone at different sensor cavity lengths with increasing frequency

Fig. 8. Variation of phase acoustic-pressure sensitivity of uwFBG hydrophone at different sensor cavity lengths when vibration signal frequency is 10 Hz with amplitude of 10-500 mV

Fig. 9. Time domain diagram of underwater acoustic signal demodulated by four uwFBG hydrophones when vibration signal frequency is 10 Hz with amplitude of 400 mV

Fig. 10. Frequency domain diagram of underwater acoustic signal demodulated by four uwFBG hydrophones when vibration signal frequency is 10 Hz with amplitude of 400 mV