FIBER-OPTIC INTERFEROMETRIC DEVICE FOR DETECTING PHASE SIGNALS Russian patent published in 2017 - IPC G02B6/26 G02B6/00 G01R15/24 G01B9/02 

FIELD: physics.

SUBSTANCE: fiber-optic interferometric device for detecting phase signals, including optically coupled a source of coherent optical radiation, a phase modulator, a device for distributing optical power, a sensitive part including, at least, one sensor element representing a segment of the sensing optical fiber located between the two fiber Bragg gratings (FBG) of the same resonance wavelength, located at the predetermined distance, and a photodetecting device with a demodulation circuit. The input of the phase modulator is coupled to the source of the coherent optical radiation, and its output is coupled to the first device port for distributing the optical power, the second port of which is coupled to the sensitive part, and the third device port for distributing the optical power is coupled to the input of the photodetecting device, and the length of the sensor element (L_se) and the laser pulse duration of the coherent optical radiation source (t_pul) are coupled by the ratio:

,

where c - the light velocity, n - the refractive index of the sensor element optical fiber, t_pul - the duration of the laser pulse, L_se - the length of the sensor element.

EFFECT: creating a fiber-optic interferometric device for recording different phase signals, which allows to eliminate the useful signal distortion and to reduce optical losses while simplifying the construction.

4 dwg