Closed-loop detection method of atomic gyroscope on basis of photoelastic modulation

Abstract

The invention provides a closed-loop detection method of an atomic gyroscope on the basis of photoelastic modulation. The closed-loop detection method comprises the following steps: a Faraday actuator is placed in front of a 1 / 4 wave plate and a photoelastic modulator; detection laser passes through a polarizer, a Faraday modulator, an alkali-metal gas chamber, the 1 / 4 wave plate, the photoelastic modulator and an analyzer in sequence, a fast axis of the 1 / 4 wave plate and an optical axis of the polarizer are in the same direction, a fast axis of the photoelastic modulator and the optical axis of the polarizer form a 45-degree angle, and the analyzer and the optical axis of the polarizer form a 90-degree angle; a deflection angle of the closed-loop Faraday actuator is controlled by a PID (Proportion Integration Differentiation) controller, the output of a lock-phase amplifier is kept to be zero, and at the same time, the rotating angle to be detected is read out by an output angle of the closed-loop Faraday actuator. The closed-loop detection method provided by the invention has the advantages that the rotating angle to be detected is only related to the rotating angle of the closed-loop Faraday actuator and is not related to the light intensity and the photoelastic modulation amplitude, so that the influence of parameter fluctuation on a detection system is isolated on the principle, a scale factor of the closed-loop photoelastic modulation detection is easily stabilized, and the detection accuracy of the atomic gyroscope is improved.

Description

technical field [0001] The invention belongs to the technical field of atomic gyroscope detection methods, in particular to a photoelastic modulation-based atomic gyroscope closed-loop detection method suitable for SERF atomic spin gyroscopes and nuclear magnetic resonance gyroscopes. Background technique [0002] The detection of atomic spin precession can finally be mapped to the detection of the rotation angle of the polarization plane of the linear polarization detection laser. At present, there are mainly three detection methods for the linear polarization rotation angle of SERF atomic spin gyroscopes and nuclear magnetic resonance gyroscopes: differential Faraday modulation method, photoelastic modulation method and differential polarization method. [0003] The differential polarization method has the advantages of simple structure and easy implementation. However, due to the lack of modulation, when the atomic spin precession angle to be measured is a low-frequency ...

AI Technical Summary

Problems solved by technology

This results in a drop in the Faraday modulation amplitude, reducing the signal-to-noise ratio of the detection system

[0005] The photoelastic modulation method is similar to the Faraday modulation method. The photoelastic modulation is used instead of the Faraday modulation. The system output still includes scale factors such as light intensity and modulation amplitude. The scale factor is difficult to stabilize and reduces the detection accuracy.

However, there is no atomic gyroscope detection method that can isolate and detect interferences such as laser light intensity fluctuations, Faraday modulation amplitude fluctuations, and photoelastic modulation amplitude fluctuations, so as to achieve high-precision detection of atomic gyroscopes and improve the accuracy of atomic gyroscopes.

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