Research On White Light Febry-Perot Interferometric Optic Fiber Accelerometer

The fiber optic accelerometer(FOA) is a novel accelerometer based on displacement detection using optical signal, which is of high potential precision, large dynamic range, high reliability and long life. A FOA which can be used to measure the direct signal of acceleration is developed as an initial instrument.Firstly, three types of FOA are researched, including the intensity modulated, the wavelength modulated and the phase modulated. After an analysis on performance of the extrinsic Fabry-Perot interferometer(EFPI) and the intrinsic Fabry-Perot interferometer(IFPI), A FOA scheme based on the EFPI and the spectrum domain white light interference demodulation method is proposed.Structure parameters influencing the scale factor are analyzed. Then, specific structure parameters are confirmed by the static simulation function of ANSYS. The tunable laser drive circuit is designed with ADN8831, ADN8810 and FPGA, and the drive program is designed with Verilog HDL in Quartus II. Meanwhile, the upper computer software is designed with labVIEW.At last, the performance test shows that, the FOA can offer a scale factor stability of 1.7×10-4, a zero stability of 1.4×10-4g(1?), a measuring range of ±25g, and a resolution of 1.8×10-5g. The model of the optical priciple error, the cross sensitivy error and the error induced by environment temperature are built. With a purpose of obtaining the exact data, the simulation and experiment are conducted. Results show that, the measurement error of interrogation algorithm decrease with the signal-to-noise ratio increasing and the spectrum sampling interval shortening, and the measurement accury is 4.5×10-5g; under the effect of one times gravitational acceleration, the cross sensitivity error is 1.8mg; the scal factor will increase when the temperature rises in the range from-40? to 60?, and the increasing rate in low temperature parts is greater than the high temperature parts.