Research on key technology of underwater acoustic communication based on Sagnac fiber optic hydrophone

This paper reports a kind of OFDM underwater acoustic communication technology based on Sagnac fiber optic hydrophone. It adopts the fiber optic hydrophone technology based on Sagnac fiber ring composed of 3x3 fiber coupler. The sampling rate of the system is 48kHz, the fiber optic hydrophone can achieve up to 12.3kHz underwater acoustic detection bandwidth and -140dB (0dB re 1rad/ mu Pa) sound pressure sensitivity. According to the test results of the underwater acoustic communication experiment, the underwater acoustic communication rate is up to 24kbps, the bit error rate is at the magnitude of 10(-2), and the simulation communication rate is up to 100kbps. Sagnac fiber optic hydrophone shows excellent low-frequency suppression ability and simple structure, which are very suitable for underwater acoustic communication.