一种响应平坦的宽带高灵敏度分布反馈光纤激光水听器

A distributed feedback fiber laser hydrophone with high sensitivity and flat frequency response

采用聚氨酯材料制作的梭形结构对分布反馈(DFB)光纤激光器进行封装,在驻波管校准声场对其进行测试,由OPD4000相位解调仪精确测量光纤激光水听器的相移量。通过测试和数据分析,得到1 kHz处DFB光纤激光水听器的相位-声压灵敏度为-122.6 dB re rad/μPa,相当于3.8 nm/MPa;在10 Hz～10 kHz整个频段内频响曲线非常平坦,波动小于±9 dB,并且信噪比与标准压电水听器相当。

A distributed feedback （DFB） fiber laser is packaged with a polyurethane spindle structure for acoustic sensing. It is tested in a standing wave tube calibration field. Phase demodulator OPD4000 is employed to precisely measure the phase shift. We obtain the phase sensitivity of - 122.6 dB re rad/gPa, i. e. 3.8 nm/MPa at 1 kHz. The frequency response is flat in the range of 10 Hz - 10 kHz with the fluctuation of no more than ＋9 dB. Its signal and noise ratio （SNR） is equal to standard PZT hydrophone.