METHOD OF DETERMINING TRANSFER FUNCTION OF A PHASE MODULATOR IN A SAGNAC INTERFEROMETER Russian patent published in 2020 - IPC G01B9/02 

FIELD: optics.

SUBSTANCE: invention relates to fiber optics. Method for determining the transfer function of a phase modulator in a Sagnac interferometer includes feeding a phase modulator electric input of a voltage control signal comprising an auxiliary meander signal, amplitude of which provides shift of the operating point of the interferometer to the linear portion of the interferometric function, and measurement of obtained signal of interferometer, which is used to determine transfer function of phase modulator. At the electric input of the phase modulator, simultaneously with the auxiliary signal, a second control signal of voltage in the form of a meander with an amplitude corresponding to the optical phase shift and with a certain period is supplied and the obtained signal of the interferometer is measured, from which the phase signal is calculated. Pulse characteristic of the phase modulator is calculated from the phase signal and, subjecting the obtained pulse characteristic to the method of identifying the transfer function, determining the desired transfer function of the phase modulator of the Sagnac interferometer.

EFFECT: high accuracy of determining the transfer function of a photomultiplier in a Sagnac interferometer.

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