Minimum-deviation Demodulation Algorithm for Measurement of Fiber Optic Pressure Sensors
SHEN Ya-feng1,2,JIANG Yi1,SUI Guang-hui2
1. School of Optical and Photonics,Beijing Institute of Technology,Beijing 100081,China
2. AVIC Changcheng Institute of Metrology and Measurement,Beijing 100095,China
Abstract：When the gas pressure measurement is performed with fiber optic pressure sensors based on EFPI structures, a high-resolution cavity length measurement method is required, because the sensor structure determines that the dynamic range of the cavity length is relatively small. A high precision minimum-deviation cavity-length demodulation algorithm is proposed and experimentally demonstrated. The absolute cavity length of an optical fiber pressure sensor based on EFPI structure is recovered by using the demodulation algorithm. Through sealing an EFPI fiber optic pressure sensor in a pressure standard source, the real-time measurement of gas pressure is realized. The experimental results show that the cavity length of the EFPI fiber pressure sensor has a good linear relationship and repeatability with the change of pressure. The repeatability of cavity length measurement is±1nm, the nonlinear error is 0.1496%,the repeatability of pressure measurement is 0.12%, and the accuracy of pressure measurement is better than 0.5%.
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2023, Vol. 44 
