分布式光纤光栅传感复用解调方法研究

Research on distributed fibre Bragg grating sensor multiplexing demodulation method

受到光纤光栅的串扰与噪声的干扰,导致分布式光纤光栅传感复用解调方法存在波长偏差大、解调精度低的问题,因此,在传统解调方法的基础上实现优化设计。确定传感器类型与布置方式,搭建对应的分布式光纤光栅传感网络模型,在该模型下分析传感耦合特征。以传感特征分析结果为基础,设计并安装降噪复用解调器,以此作为解调方法的实现介质,并实现对串扰噪声的抑制。根据传感特性选择适宜的复用方式和解调方法,通过光电转换、中心波长标定等多个步骤,实现对分布式光纤光栅传感的复用解调。通过与现有解调方法的对比得出结论:与文献[3]提出的方法相比,设计方法的解调波长偏差降低了0.0025 nm,与文献[3]提出的方法相比解调波长偏差降低了0.0031 nm,分辨率提高了0.5 pm。

Due to the interference of crosstalk and noise of fibre Bragg grating,the demodulation method of distributed fibre Bragg grating sensor multiplexing has the problems of large wavelength deviation and low demodulation accuracy.The sensor type and arrangement mode were determined,the corresponding distributed fibre Bragg grating sensor network model was built,and the sensor coupling characteristics were analysed under the model.Based on the analysis results of sensing characteristics,the demodulator is designed and installed,which can be used as the demodulator to suppress crosstalk noise.According to the sensing characteristics,the suitable multiplexing method and demodulation method are selected,and the multiplexing demodulation of distributed fibre Bragg grating sensing is realized through photoelectric conversion,central wavelength calibration and other steps.By comparing with the existing demodulation methods,it is concluded that compared with the method proposed in literature[3],the demodulation wavelength deviation of the design method is reduced by 0.0025 nm,compared with the method proposed in literature[3],the demodulation wavelength deviation is reduced by 0.0031 nm,and the resolution is improved by 0.5 pm.