Feedback-stabilized interrogation technique for optical Fabry–Perot acoustic sensor using a tunable fiber laser

Abstract

This paper discusses a new stabilization technique used to measure acoustic signals over a large range of operating temperatures. The new stabilization technique is based on a diaphragm-based extrinsic Fabry–Perot interferometer (EFPI) acoustic sensor and feedback stabilization using a tunable fiber laser. The feedback stabilization technique is used to control the output wavelength of the tunable fiber laser to operate in the linear range of the diaphragm-based EFPI acoustic sensor. This method has no signal detection bandwidth limit, a high tuning speed, and a large tunable range. To verify the performance of the stabilization technique, we measured the output of the sensor by changing the environmental temperature, and the experimental results demonstrate that this system can stabilize the operating point of the sensor very well. An acoustic signal was successfully detected using a photoacoustic spectrometer system, and the fade-out problem was solved.