A wide-range demodulation method for FBG sensor

作者:Chen, Jiajia; Shi, FuQuan; Lei, Xueqin; Peng, Baojin*
来源:Microwave and Optical Technology Letters, 2016, 58(10): 2416-2419.
DOI:10.1002/mop.30064

摘要

The principle, structure design, and experimental setup of a fiber Bragg grating (FBG) sensor based on matching grating are introduced. The FBG sensor requires several fiber gratings to demodulate. This study proposes a simple signal detection method to demodulate the resonance wavelength shift of the FBG. Photodiodes convert the reflected light signal of every fiber grating into electrical signal. The reflected light signals are then collected by a computer through a data collection box. The physical quantity is reported in real time according to the calibrated data. This method has a wider range of demodulation and displays the drift of center wavelength of sensor FBG in real time. The temperature/strain cross-sensitivity issue of FBG sensor is solved to some extent due to the same temperature drift of the same type of FBG. Experimental results show that the system has a wavelength measurement error of less than 0.009 nm, and the corresponding microstrain measurement error is less than 7.5 epsilon.