在基于快速傅里叶变换的光纤法布里-珀罗传感器解调方法的理论分析基础上,引入了离散频谱能量重心校正方法,改进了FFT算法。仿真结果表明该联合算法解调值与真实值一致性较好。并通过实验加载0~10 Mpa的油压,对压力和解调得到的传感器腔长数据进行拟合,并将拟合得到的曲线与参考值比较,相对误差为0.003%。实验结果表明,FFT与能量重心联合解调方法可以得到较高的精度。

In this paper, the fast Fourier transform (FFT) demodulation method for Fabry-Perot sensors is theoretically analyzed and a kind of energy centrobaric correction method for discrete spectrum is proposed to improve the precision of traditional FFT demodulation method. In the simulation, the demodulation results match the real length of the Fabry-Perot cavity very well. In the experiment, the cavity is varied by oil pressure ranging from 0 to 10 Mpa. By fitting the curves of demodulation results with that of reference value, the relative error is 0.003%. Experiments show that this new method serves the purpose of high resolution demodulation for Fabry-Perot sensors.