ABSTRACT
This chapter describes a new all-fiber acoustic pressure sensing system with high dynamic range and high sensitivity. A new all-fiber system is introduced to realize the acoustic pressure sensing. Acoustic wave is detected by the photoelastic effect of fiber and demodulated by all-fiber interferometer. Acoustic sensors have been widely applied in our world and played a very important role in military, health care and our daily life. There are three basic parameters in acoustic measurement: acoustic pressure, acoustic intensity and acoustic power. For the reason that acoustic intensity and acoustic power can be derived from acoustic pressure under the condition of free acoustic field, we can choose the acoustic pressure as the measurement goal. Different from the traditional acoustic sensor, the fiber acoustic sensor can change the acoustic signals into optical signals. The phase change caused by acoustic disturbance is on the sideband of carrier fundamental frequency and double frequency.
