Fiber-Optic Extrinsic Fabry-Perot Interferometer Pressure Sensor Demodulation System with Three Quadrature Signals

摘要

A demodulation algorithm for fiber-optic extrinsic Fabry-Perot interferometer (EFPI) pressure sensor is proposed and demonstrated in this chapter. This method provides a wide range of pressure measurement and overcomes disadvantages of the traditional small sensing scale. The length of the sensing cavity could be recovered by using three quadrature phase-shifted signals. A theoretical description of the method is given here. An experimental sensing platform and calibrated behavior of the system were set up to prove the method. The results showed that the sensing accuracy is higher than 0.3 μm over a large range of 20 μm.