Heterodyne technology based device and method for testing half-wave voltage of phase modulator

Abstract

The invention discloses heterodyne technology based device and method for testing the half-wave voltage of a phase modulator. The device comprises a laser, a first 50-percent coupler, a phase modulator, an acousto-optic frequency shifter, a second 50-percent coupler, a photoelectric detector, a vector analyzer, a first signal generator and a second signal generator; the laser is sequentially connected with the first 50-percent coupler, the phase modulator, the second 50-percent coupler, the photoelectric detector and the vector analyzer, the first 50-percent coupler is sequentially connected with the acousto-optic frequency shifter and the second 50-percent coupler, the phase modulator is connected with the first signal generator, and the acousto-optic frequency shifter is connected with the second signal generator. The invention provides the method for accurately testing the half-wave voltage of the phase modulator, the carrier component in phase modulation can be effectively inhabited by utilizing the half-wave voltage obtained through testing, the back-scattered noise in a resonance type optical gyroscope is reduced, the invention provides a feasible method for improving the precision of the resonance type optical gyroscope and has important scientific meanings and application value.

Description

technical field [0001] The invention relates to a device and method for testing the half-wave voltage of a phase modulator based on heterodyne technology. By accurately measuring the half-wave voltage of the phase modulator, the backscattering noise in the resonant optical gyroscope can be effectively suppressed, and the performance of the resonant optical gyroscope can be improved. precision. Background technique [0002] Resonator Fiber-Optic Gyroscope (RFOG: Resonator Fiber-Optic Gyroscope) is a high-precision inertial sensor based on the Sagnac effect to detect angular velocity. It obtains the rotational angular velocity of the object by detecting the resonant frequency difference generated by the clockwise and counterclockwise propagation of light in the detection system. Compared with the interferometric optical gyroscope, the resonant optical gyroscope has great advantages in miniaturization and integration. [0003] The resonant optical gyroscope using sine wave pha...

AI Technical Summary

Problems solved by technology

The M-Z interferometry uses two 50% couplers to form an M-Z interferometer structure, and obtains the half-wave voltage by measuring the number of half-waves of the interference light intensity. The measurement accuracy of this method is poor, and it cannot meet the measurement of tens to hundreds of ppm. precision

The square wave modulation is used in the interferometric gyroscope, and high precision can be achieved by observing the output square wave level, but this method is only applicable to the interferometric gyroscope system with square wave modulation, and the implementation is relatively complicated

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