ARMS LENGTH DIFFERENCE DETERMINING METHOD IN THE DOUBLE-BEAM FIBER-OPTICAL INTERFEROMETER Russian patent published in 2019 - IPC G01B9/02 

FIELD: instrument engineering.

SUBSTANCE: invention relates to the field of fiber-optic measuring instruments. Arms lengths difference determining method in the two-beam fiber-optic interferometer consists in the frequency-modulated optical signal generation, directed into the two-beam fiber-optic interferometer by means of the laser diode frequency modulation and the interference signal recording on the photodetector. Frequency-modulated optical signal is additionally modulated in amplitude using the amplitude modulator by means of its supplying with the constant duty cycle and the same amplitude rectangular electric pulses and directing it to one or N interferometers, combined into the array with time multiplexing, in each interferometer reference arm, performing the auxiliary modulation by the passing through this arm optical pulse phase, performing the received interference signal demodulation, and recording the output useful phase signal. Calculating the double-beam fiber-optic interferometer reference and sensitive arms lengths difference.

EFFECT: technical result consists in provision of combined into the array with time multiplexing one or several fiber-optic interferometers arms lengths difference simultaneous determination, regardless of the interferometers working points position.

1 cl, 3 dwg