A Miniature Fiber-Optic Microphone Based on an Annular Corrugated MEMS Diaphragm

A miniature fiber-optic microphone (FOM) based on a periodic corrugated microelectro-mechanical-system (MEMS) diaphragm has been developed in this paper. A micro Fabry-Perot cavity is an acoustic sensor structure made up of a single-mode fiber(SMF) end face and a MEMS diaphragm. The achieved signal-to-noise ratio (SNR) of the FOM is 79.08 dB under the sound pressure of 37.76 mPa at the 1 kHz acoustic signal, and the corresponding minimum detectable pressure is as low as 2.97 μPa/Hz
^1/2
. In addition, the FOM has a flat frequency response and a linear sound pressure response within the audible sound frequency range. These results indicate that this FOM shows the extreme sensitivity and miniature size, making it a promising technology for acoustic detection.