带加速度补偿的DFB光纤激光水听器

DFB Fiber Laser Hydrophone with Acceleration Compensation

针对分布反馈式光纤激光水听器在用于水声探测时极易受加速度效应干扰的问题,设计了一种双膜片对称结构的光纤激光水听器,对该水听器的抗加速度性能进行了研究.建立了双膜片结构水听器的加速度灵敏度理论模型,分析了水听器各部件的尺寸大小、材料参量与水听器加速度灵敏度的关系,实现了对水听器结构的优化设计;加工制作了分布反馈式光纤激光水听器原型样品,并进行了实验研究.测量结果表明,在2.5~10kHz的频率范围内,该结构水听器的平均声压灵敏度为-132.6dB,波动幅度不大于±0.5dB,加速度灵敏度小于-28dB.该水听器在保证了较高声压灵敏度与平坦的响应曲线的同时,抗加速度性能也得了有效改善,可大大提高光纤激光水听器阵列在运动状态下对远距离目标探测的信噪比.

To reduce the disturbance of acceleration effects on distributed feedback fiber laser hydrophone used in underwater sound detection, one symmetric structure with two diaphragms was designed and its anti-acceleration performance is investigated. The theoretical acceleration sensitivity model of the hydrophone with two diaphragms was established. After the relation between acceleration sensitivity and component size, materials parameters were analyzed, the structure of the hydrophone was optimized. Prototype of the hydrophone was fabricated and tested. The average pressure sensitivity reaches --132.6 dB with the fluctuation less than ＋_0.5 dB in the frequency range of 2.5~10 kHz, while the acceleration sensitivity is less than --28 dB. The results show that this structure of hydrophone ensures the high pressure sensitivity and flat response curve, whose anti-acceleration performance is improved at the same time, which will greatly enhance the signal-to-noise ratio of the hydrophone in the moving state.