FIBER-OPTIC DEVICE FOR DETECTING VIBRATION EFFECTS WITH PHASE RECOVERY WITH REDUCED EFFECT OF INSTABILITIES OF THE RECORDING INTERFEROMETER Russian patent published in 2020 - IPC G01H9/00 

FIELD: physics.

SUBSTANCE: invention relates to fiber-optic sensor systems based on phase-sensitive reflectometry with phase recovery used in systems of monitoring extended objects. Disclosed fiber-optic device for recording vibration effects with phase recovery with reduced influence of instabilities of the recording interferometer includes: a highly stable narrow-band radiation source, from which through splitter 1×2 greater part of radiation falls into controlled line, and smaller serves for direct registration of parameters of radiation source and receiving part of device. After one of the outputs of splitter 1×2 there arranged in series are an optical signal amplifier (booster), an acoustooptical modulator controlled by a driver, optical circulator, controlled line of optical fiber, weak signal amplifier (preamplifier), filter for required wavelength. At the filter outlet there is a circulator, in the forward direction of which first splitter 3×3 is located, non-equable Mach-Zehnder interferometer with optical path difference, second splitter 3×3, first three radiation receivers. Splitter 1×2 second output is connected to the circulator in the receiving part in front of the receivers so that radiation from the highly stable narrow-band radiation source, passing in the reverse direction, second splitter 3×3, non-equable Mach-Zehnder interferometer with optical path difference, first splitter 3×3, falls on the second three radiation receivers. Outputs of all receivers are connected to analogue-to-digital converters of computing device.

EFFECT: reduced error of recovery of the phase detected from the monitored signal line.

1 cl, 2 dwg