弱反射光纤光栅水听器拖曳线列阵  

A Towed Line Array with Weak Fiber Bragg Grating Hydrophones

作　　者：丁朋 黄俊斌[1] 庞彦东 周次明[3] 顾宏灿[1] 唐劲松[2] DING Peng;HUANG Junbin;PANG Yandong;ZHOU Ciming;GU Hongcan;TANG Jinsong(Department of Weapon Engineering,Naval University of Engineering,Wuhan 430033,China;College of Electronic Engineering,Naval University of Engineering,Wuhan 430033,China;College of Information Engineering,Wuhan University of Technology,Wuhan 430033,China)

机构地区：[1]海军工程大学兵器工程学院,武汉430033 [2]海军工程大学电子工程学院,武汉430033 [3]武汉理工大学信息工程学院,武汉430033

出　　处：《光子学报》2021年第7期46-58,共13页Acta Photonica Sinica

基　　金：国家自然科学基金(No.11774432),湖北省自然科学基金(No.2018CFB788)。

摘　　要：提出一种细尺寸、大孔径、高增益的弱反射光纤光栅水听器拖曳线列阵。根据匹配干涉方法选用反射率一致、中心波长相同以及3 dB带宽较宽的弱反射光纤光栅阵列;根据水声传感原理确定弱反射光纤光栅阵列的栅距以应用于5~10 Hz甚低频水声信号探测。采用光纤涂覆机对弱反射光纤光栅阵列二次涂覆,阵列中心波长整体一致漂移,栅距基本不变。采用扎纱机和护套机在二次涂覆弱反射光纤光栅阵列外铺设凯夫拉纤维和聚氨酯保护套形成水听器拖曳线列阵。测试拖曳线列阵水听器单元的声压-相位灵敏度在1 rad/μPa条件下分别为−136.97 dB@5 Hz、−139.64 dB@7.5 Hz、−139.36 dB@10 Hz;分析流噪声引起的水听器自噪声功率谱,拖速为8 m/s、频段为1~100 Hz的谱值在45~95 dB(1μPa2/Hz)范围内。实验和分析结果表明,所提出的弱反射光纤光栅水听器拖曳线列阵甚低频段灵敏度高、流噪声低,有望增强无人航行器的甚低频水声信号探测功能。A thin,large aperture,high gain towed line array with weak fiber Bragg gating hydrophones is proposed.A weak fiber Bragg gating array with the same reflectivities,central wavelengths and wide 3 dB bandwidths is selected according to the principle of matched interference,and the grating spacing of the weak fiber Bragg gating array is determined according to the principle of underwater acoustic sensing for 5~10 Hz very low frequency underwater acoustic signals detection.Central wavelengths of the weak fiber Bragg gating array are uniformly shifted and the grating spacing is basically unchanged when the weak fiber Bragg gating array is coated by an optical fiber coating machine.Kevlar and polyurethane protective sheath are laid outside the weak fiber Bragg gating array by an yarn binding machine and sheath machine to form hydrophone towed array.The sound pressure-phase sensitivities of the towed linear array hydrophone unit are measured as−136.97 dB(1 rad/μPa)@5 Hz、−139.64 dB@7.5 Hz、−139.36 dB@10 Hz.The self noise power spectrum of the hydrophone caused by flow noise is analyzed,and the spectrum value is in the range of 45~95 dB(1μPa2/Hz)in the frequency band of 1~100 Hz under 8 m/s towing speed.The experimental and analytical results show that the proposed towed line array has high sensitivity and low flow noise in very low frequency band,which is expected to increase the detection function of very low frequency underwater acoustic signals for unmanned aerial vehicles.

关 键 词：光纤布拉格光栅 弱反射 水听器 拖曳线列阵 

分 类 号：TN253[电子电信—物理电子学]