Study of the planar optical fiber Bragg grating hydrophone probe with acceleration compensation

Since the probe acceleration response of a planar optical FBG hydrophone is very obvious and has an adverse influence on normal underwater acoustic pressure detection,an acceleration desensitization method employing an acceleration compensation measure is presented here.Results indicate that by utilizing this method,the equivalent pressure output applied by one unit of acceleration(1m·s^-2) is reduced from a range of 2.52-3.26 Pa to 0.0758-0.217 Pa, while the structural sensitivity decreases from 28 fm/Pa to 20 fm/Pa,however,the resonance frequency increases slightly from 6.2 kHz to 6.5 kHz.The increased resonance frequency helps to improve the dynamic frequency characteristics,and while the structural sensitivity is reduced, it can be compensated for by improving the optical FBG dynamic wavelength interrogation sensitivity.The system sensitivity of the optical FBG hydrophone is mainly determined by its wavelength interrogation sensitivity and not the probe structure sensitivity.Therefore,the acceleration compensation method would have broad practical applications.