Abstract:

     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/μPa, 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.

Key words: distributed feedback fiber laser hydrophone, frequency response, acoustic sensitivity