Frequency response comparison of two FBG-based hydrophones

摘要

Fiber optic hydrophones are useful for a variety of underwater monitoring applications, as they offer high sensitivity, signal-to-noise ratio and multiplexing ability for marine acoustics and offer longer term reliability than conventional electronic hydrophones. The frequency response of packaged fibers depends strongly on the material and mechanical parameters of the sensor design. Two fiber bragg-grating (FBG)-based hydrophones are described and their frequency response is measured. One consists of a diaphragm-linked FBG, and another is a polymer coated FBG. While the diaphragm-linked FBG has predictable resonances, resonance features on the simpler coated FBG hydrophone are observed as well.