Resonance type optical gyro detection system and method based on combination of reciprocity modulation and time division switching

Abstract

The invention discloses a resonance type optical gyro detection system and method based on combination of reciprocity modulation and time division switching. Firstly, reciprocity modulation is carriedout on light emitted by a laser, then two paths of light in clockwise and anticlockwise directions (relatively along the propagation direction of an optical resonant cavity) are obtained on a Y branch, and modulation signals with different frequencies are simultaneously applied to modulate the two beams of light; Y-branch output enters a 2 * 2 optical switch for time division switching, and output of the Y-branch output enters an optical resonant cavity. A cavity outlet signal is subjected to same-frequency demodulation, and one path of demodulated signal is fed back to a laser tuning end after being subjected to signal processing, so that the laser frequency is locked on the path of resonant frequency. The other path of demodulated signal is output as a gyro rotation signal after signalprocessing. The resonant mode optical gyro detection method provided by the invention is beneficial to inhibiting the influence of non-reciprocal noise such as residual intensity modulation on the basis of increasing the system carrier rejection ratio and inhibiting backscattering noise, and the detection precision of the resonant mode optical gyro is improved.

Description

technical field [0001] The invention relates to the technical field of signal detection, and relates to a detection system and method for a resonant optical gyroscope based on the combination of reciprocity modulation and time-division switching of 2×2 optical switches. Resonant gyroscopes include resonant fiber optic gyroscopes with optical fiber ring resonators as sensitive components and resonant integrated optical gyroscopes with optical resonant cavities as core sensitive components. Background technique [0002] Resonator Optic Gyroscope (ROG) is a high-precision inertial sensor that uses the optical Sagnac effect to detect rotation. The resonant optical gyroscope without vibrating parts has the advantages of miniaturization, high precision and anti-vibration. Compared with Micro Electro Mechanical Systems (MEMS) and Interferometric Fiber Optical Gyroscope (IFOG), ROG will have greater advantages. [0003] Since the Sagnac effect is a very weak effect, and the optica...

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Problems solved by technology

Laser phase modulation is generally realized by integrated optical phase modulation such as lithium niobate. Research has found that the non-ideal phase modulation characteristics of the phase modulator means that when a voltage signal is applied to the phase modulator for phase modulation, it is often accompanied by spurious intensity modulation. , the spurious intensity modulation and phase modulation signals have the same frequency characteristics, and will be demodulated by the signal demodulation module at the output end of the resonator. The influence of the spurious intensity modulation in the opposite direction is also different, and the residual intensity modulation eventually becomes a constraint on the detection accuracy of the resonant optical gyroscope.

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