Non-uniform strain fiber bragg grating demodulation method based on spectral shape

The invention provides a non-uniform strain fiber Bragg grating demodulation method based on a spectral shape, and the method comprises the steps: segmenting an FBG into a plurality of sub FBGs, enabling the periodical change period of the refractive index of each sub FBG to have an obvious difference, and outputting the wavelengths of the plurality of sub FBGs through a deep learning or fitting method, and enabling the wavelengths to serve as a demodulation result. A traditional FBG demodulation algorithm only outputs a peak searching result and cannot accurately reflect the true situation of a non-uniform strain FBG, and the new method provided by the patent takes the whole shape of an FBG reflection spectrum as a data analysis object, increases a new demodulation dimension, can more accurately reflect the true strain of the FBG, and can be applied to the sensing fields of optical fiber shape sensors and the like. 本发明提供一种基于光谱形状的非均匀应变光纤布拉格光栅解调方法，所述方法包括：将FBG分段为多个子FBG，每个子FBG的折射率周期性变化的周期具有明显的差异，通过深度学习或拟合的方法输出多个