Frequency response of fiber-optic hydrophone with a novel mechanical anti-aliasing filter of side cavities

摘要

We demonstrate a novel fiber-optic hydrophone with a mechanical anti-aliasing filter of side cavities. The amplitude and phase frequency response properties are presented with an acoustic equivalent circuit. Theoretical results show that the hydrophone has very flat low frequency response, and can greatly attenuate high frequency sound. The response curve has three resonant frequencies and an inverse resonant frequency, which is induced by the side cavities and contributes much to the high frequency attenuation. The hydrophone is tested in a standing-wave tube filled with water, and the measured frequency responses accord well with the theoretical results.