To demodulate different kinds of complex non-periodic signals and improve the accuracy and stability of non-periodic signal demodulation,a phase demodulation method for non-periodic signals detected by fiber Bragg grating(FBG)sensors is proposed.On the basis of studying the spectral characteristics of non-periodic signals,the sensing principle of fiber Bragg gratings is analyzed,and it is concluded that temperature sensing and strain sensing can cause changes in Bragg wavelength,resulting in changes in the phase of non-periodic signals.Combined with the use of non-equilibrium M-Z fiber interference demodulation method,non-periodic signals are demodulated;the DC phase tracking zero difference method is adopted to offset the DC zero drift and restore the original signal of non-periodic dynamic signals without distortion.The experimental results show that the combination of fiber Bragg grating sensing and unbalanced M-Z interferometer for detect-ing non-periodic signal phase demodulation has high sensitivity,accuracy,and stability.
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