The invention discloses an optical
frequency domain reflection-distributed vibration frequency sensing and locating device and a
demodulation method. A technical method of optical
frequency domain reflection beat frequency interference of a self-injective
mode locking laser of a linear turning ultra-narrow linewidth
whispering gallery mode is adopted in the optical
frequency domain reflection-distributed vibration frequency sensing and locating device. The optical frequency domain reflection-distributed vibration frequency sensing and locating device comprises a main interferometer which is used to obtain a sensing
signal and an auxiliary interferometer of a
clock trigger
signal. The
demodulation method comprises that
wavelength domain information is obtained by the main interferometer,
fast Fourier transform is used to transform the
wavelength domain information, and then distance domain information is obtained. A group of static reference signals and a group of vibration signals are collected. The distance domain information, namely local distance domain information, is selected in sequence by moving windows. Complex number cross correlation is used on the static signals and the vibration signals of the local distance domain information on each position. According to a
noise coefficient of the complex number cross correlation, a position of a vibration point is obtained. A subsidiary
summit position of the complex number cross correlation of the local distance domain information on the position of the vibration is picked up, and the subsidiary
summit position is vibration frequency information.