Research of the planar optical fiber bragg grating hydrophone probe with acceleration compensation methods

Aimed at that the probe acceleration response of planar FBG hydrophone is very obvious and has an adverse influence of the normal underwater acoustic pressure detection,An acceleration desensitization method using the acceleration compensation measure is put forwards in this paper.Research result shows that by this step,the equivalent pressure output applied by one unit acceleration(1 m·s^-2) is reduced from 2.52~3.26 Pa to 0.0758~0.217 Pa. At the same time,the structure sensitivity is also decreased from 28 fm/Pa to 20 fm/Pa,however,the resonance frequency is increased from 6.2 kHz to 6.5 kHz.The increased resonance frequency help to improve itself dynamic frequency characteristic,however,the reduced structure sensitivity can be compensated by improving the FBG dynamic wavelength interrogation sensitivity.Originally,with regard to the FBG or FBG laser hydrophone,the system detectable sensitivity is mainly determined by its wavelength interrogation sensitivity,not the probe structure sensitivity.So this acceleration compensation method is of considerable utility.