WANG Junjie1 DING Tengjiao1 JIANG Desheng1 XIE Guanmo1 HUANG Junbin2

(1　  Key Laboratory of Fiber Optic Sensing Technology and Information Processing of Ministry of Education, Wuhan University of Technology  Wuhan 430070)

(2　  Department of Weaponry Engineering, Naval Univ. of Engineering  Wuhan 430033)

Received Apr. 28, 2009

Revised Oct. 27, 2010

Abstract 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 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.

PACS numbers: 43.38,43.58,43.30