High-Sensitivity Miniaturized Fiber-Optic Hydrophones

This article introduces the design and experimental verification of a fiber-optic hydrophone. This kind of optical fiber hydrophone is composed of a Michelson interferometer, and the sensitivity enhancement structure is optimized through finite element analysis to improve sensitivity. The developed hydrophone has the characteristics of small size and high sensitivity. In the case of reduced diameter, high sound pressure sensitivity can still be ensured. In the frequency band below 2 kHz, the sensitivity of the hydrophone sample is -140 dB, and the sensitivity fluctuation does not exceed 4 dB.