基于人工神经网络的瑞利散射频谱解调方法  

Method for Rayleigh Scattering Spectral Demodulation Based on Artificial Neural Network

作　　者：王一凡 刘庆文 何祖源 Wang Yifan;Liu Qingwen;He Zuyuan(State Key Laboratory of Advanced Optical Communication Systems and Networks,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学区域光纤通信网与新型光通信系统国家重点实验室,上海200240

出　　处：《光学学报》2021年第13期98-103,共6页Acta Optica Sinica

基　　金：国家重点研发计划(2018YFC1503703);国家自然科学基金(61875121,61620106015)。

摘　　要：基于瑞利散射频谱的分布式光纤传感系统具有线性度好、可同时检测动态和静态信号的优点,但基于互相关运算的常规解调技术存在计算量非常大的问题。提出一种使用人工神经网络(ANN)算法代替互相关运算来提高瑞利散射频谱解调速度的方案。在该方案中,通过训练ANN模型,建立从瑞利散射曲线形状与对应的探测激光频率之间的映射关系,根据输入的待解调瑞利散射曲线,输出光纤所受到的温度或应变信息。在验证实验中,利用基于啁啾脉冲和匹配滤波器的时间门控光频域反射仪架构,获取不同探测激光频率下待测位置处的瑞利散射曲线数据,证明了基于ANN算法的数据处理方法可以正确地解调出光纤所受的应变;与基于互相关的解调方法相比,所提方法的信噪比有所降低,而计算速度提升了两个数量级以上,实现了动态信号的快速检测。The distributed optical fiber sensor based on Rayleigh spectral demodulation has the advantages of high linearity and capability for both dynamic and static signal sensing, but the traditional demodulation method based on cross-correlation requires a large amount of calculation. Here we propose a new demodulation method based on an artificial neural network(ANN) instead of cross-correlation operation to boost the speed in the demodulation of Rayleigh backscattering spectra, in which an ANN model is first constructed and trained to map the Rayleigh scattering pattern to the frequency of the corresponding probe laser. Then, the strain or temperature information of the fiber is figured out from the input Rayleigh scattering curve to be demodulated. In the verification experiment, the Rayleigh backscattering traces at the detection position under different probe laser frequencies are obtained using time-gated digital optical frequency domain reflectometry in which chirped pulses and matched filters are employed. It is verified that the strain applied to the fiber can be correctly demodulated by the data-treatment method based on the ANN algorithm. Compared with the demodulation method based on cross-correlation, the proposed method possesses a lower signal-noise ratio and the calculation speed increased by two orders, which ensures the realization of the fast detection of dynamic signals.

关 键 词：光纤光学 分布式光纤传感 瑞利散射 人工神经网络 

分 类 号：TN247[电子电信—物理电子学]