A FBG-based fiber optical microphone which is insensitive with temperature and has a broad frequency band(400-2 100 Hz) is described.The fiber optical microphone is composed of a Broad Band Source(BBS),a pair of matched fiber Breagg Gratings(FBG) and a polyester diaphragm which can vibrate with acoustic waves.The pair of matched FBGs is employed for both wavelength demodulation and temperature compensation.The features make the fiber optical microphone achieve a stable operation,and make the optical microph...