Optical Fiber Fabry-Perot Acoustic Sensor Based on Large PDMS Diaphragm

摘要

An extrinsic Fabry-Perot interferometric fibre microphone based on polydimethylsiloxane, or PDMS, diaphragm wasproposed. The large free-standing PDMS diaphragm, with a diameter of 4 mm, is prepared by a simple “spin-strip”process. The experimental result shows that the fabricated sensor has a high dynamic pressure sensitivity of about -136dB re 1 rad/Pa in the range of 100~2000Hz. The noise equivalent acoustic signal level of the microphone, limited bythe environmental noise, is about 1000 Pa/Hz1/2. And the dynamic range is tested to be more than 47.48 dB. Theproposed microphone is expected to be used in the field of weak acoustic pressure testing.