Demodulation method combining virtual reference interferometry and minimum mean square error for fiber-optic Fabry–Perot sensors  

作　　者：桂新旺 Michael Anthony Galle 钱黎 梁伟龙 周次明 欧艺文 范典 

机构地区：[1]National Engineering Laboratory for Fiber Optic Sensing Technology, Wuhan University of Technology [2]Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Ministry of Education,Wuhan University of Technology [3]Department of Electrical and Computer Engineering, University of Toronto

出　　处：《Chinese Optics Letters》2018年第1期30-33,共4页中国光学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)(Nos.61377091 and61505152);the Pre-research Field Foundation of China(No.6140243010116QT69001);the Applied Basic Research Program of Wuhan,China(No.2017010201010102)

摘　　要：We propose a cavity length demodulation method that combines virtual reference interferometry（VRI） and minimum mean square error（MMSE） algorithm for fiber-optic Fabry–Perot（F-P） sensors. In contrast to the conventional demodulating method that uses fast Fourier transform（FFT） for cavity length estimation,our method employs the VRI technique to obtain a raw cavity length, which is further refined by the MMSE algorithm. As an experimental demonstration, a fiber-optic F-P sensor based on a sapphire wafer is fabricated for temperature sensing. The VRI-MMSE method is employed to interrogate cavity lengths of the sensor under different temperatures ranging from 28°C to 1000°C. It eliminates the ＂mode jumping＂ problem in the FFT-MMSE method and obtains a precision of 4.8 nm, corresponding to a temperature resolution of 2.0°C over a range of 1000°C. The experimental results reveal that the proposed method provides a promising, high precision alternative for demodulating fiber-optic F-P sensors.We propose a cavity length demodulation method that combines virtual reference interferometry（VRI） and minimum mean square error（MMSE） algorithm for fiber-optic Fabry–Perot（F-P） sensors. In contrast to the conventional demodulating method that uses fast Fourier transform（FFT） for cavity length estimation,our method employs the VRI technique to obtain a raw cavity length, which is further refined by the MMSE algorithm. As an experimental demonstration, a fiber-optic F-P sensor based on a sapphire wafer is fabricated for temperature sensing. The VRI-MMSE method is employed to interrogate cavity lengths of the sensor under different temperatures ranging from 28°C to 1000°C. It eliminates the ＂mode jumping＂ problem in the FFT-MMSE method and obtains a precision of 4.8 nm, corresponding to a temperature resolution of 2.0°C over a range of 1000°C. The experimental results reveal that the proposed method provides a promising, high precision alternative for demodulating fiber-optic F-P sensors.

关 键 词：VRI Demodulation method combining virtual reference interferometry and minimum mean square error for fiber-optic Fabry Perot sensors 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] U284.43[自动化与计算机技术—控制科学与工程]