The theory, design, fabrication, and characterization of MEMS (micro
electrical mechanical system) Fabry-Perot diaphragm-fiber optic
microphone are described in the present invention. By using MEMS
technology in processing and packaging, a square 1.9 mm.times.1.9 mm, 2
.mu. thick SiO.sub.2 diaphragm with a 350 .mu. square embossed center of
silicon is mechanically clamped to the ferrule of a single mode fiber to
keep its closeness (5 .mu.) and perpendicular orientation with respect to
the diaphragm. Static measurement of optical output power versus the
pressure on membrane reveals more than one period of Fabry-Perot
interference, thereby generating a Fabry-Perot diaphragm-fiber
interferometer device accurately reproducing audible acoustic wave.