Theoretical and experimental investigation of the intensity response of DFB-FL to external acousticexcitation

The intensity response of Distributed-Feedback fiber laser (DFB-FL) to external acoustic excitation has been investigated theoretically and experimentally. The transfer function for external acoustic excitation modulation has been obtained, and the intensity response characteristics of DFB-FL to external acoustic excitation are described by simulation. Through experiments we observe a signal of 16.5 kHz with 25 dB in the DFB-FL RIN spectrum as the external acoustic pressure is 10.25 Pa. The signal power obtained in time domain is 0.033 μW and acoustic pressure sensitivity which is calculated as –169.8 dB re μW/μPa at 16.5 kHz, which confirms that DFB-FL has the potential to be used as an intensity-type acoustic sensor.

► The intensity response of DFB-FL to external acoustic excitation was investigated.
► The transfer function for external acoustic excitation modulation was obtained.
► A signal of 16.5 kHz with 25 dB in the DFB-FL RIN spectrum was observed.
► The acoustic pressure sensitivity is –169.8 dB re μW/μPa at 16.5 kHz.