基于干涉型光纤水听器技术,设计实现了外径为20 mm的光纤光栅型拖曳水听器阵列。首先利用多波长光纤光栅连续刻写技术实现了单纤“无熔点”的光纤水听器阵列,水听器单元的平均声压灵敏度达到-143.9 dB,起伏幅度小于3 dB。利用弱反光栅组阵技术抑制了光栅阵列中的串扰噪声,串扰噪声抑制达到53 dB;利用三路偏振分集接收技术消除了阵列中的偏振衰落噪声。最终制作了外径为20 mm的32元光纤光栅拖曳水听器阵列。

Based on a interferometric optical fiber hydrophone, a fiber Bragg grating (FBG) hydrophone towed array with a diameter of 20 mm is realized. This single-fiber hydrophone array without splices is realized by using the multi-wavelength FBG continuous writing technique. The average acoustic pressure sensitivity of a hydrophone unit is -143.9 dB, and the fluctuation of sensitivity is limited within 3 dB. To suppress the crosstalk in the FBG hydrophone array, weak-reflectivity FBGs are utilized,reducing the crosstalk to 53 dB. Moreover, polarization-induced fading is eliminated by three-channel polarization diversity receiving. A 32-element FBG hydrophone towed array with a diameter of 20 mm is fabricated.