Optical fiber gyroscope frequency characteristic elevating method and device based on Faraday effect

Abstract

The invention discloses an optical fiber gyroscope frequency characteristic elevating device based on a Faraday effect. An excitation current source comprises a signal generator, a conversion amplifying circuit and a current coil, wherein a sensitive light path comprises a light source, a circulator, a Y waveguide phase regulator, a polarization beam splitter, a polarization-maintaining fiber coil, a gamma / 4 wave plate, a sensing optical fiber, a reflecting mirror and a detector; and an analog optical fiber gyroscope signal processing detection circuit comprises a front amplifying circuit, an A / D (Analog to Digital) converting circuit, a digital signal processing unit, a first D / A (Digital to Analog) converting unit, a second D / A converting circuit and a phase-locked amplifier. The Faraday effect applied in the invention is generated by exciting the sensitive light path with sinusoidal current, and a sinusoidal signal serving as an exciting signal can be output at a high frequency, so that the problem of limitation on the excitation signal output frequency during frequency characteristic test of an optical fiber gyroscope is solved, and evaluation of high bandwidth can be realized.

Description

technical field [0001] The invention relates to a method and device for evaluating the frequency characteristics of an optical fiber gyroscope based on the Faraday effect, and belongs to the technical field of inertia. Background technique [0002] Fiber optic gyro is a new type of fiber optic rotation sensor that has emerged with the rapid development of fiber optic technology. Because of its phase modulation sensing method with extremely high sensitivity, compactness and high mechanical strength, it will become a popular choice in many fields such as aerospace, aviation, and navigation. The most promising inertial component, as an important inertial sensor, measures the angular velocity of the carrier and is the core component of the inertial system, which determines the performance of the entire inertial system to a considerable extent. [0003] Fiber optic gyro is a new type of angular velocity sensor based on the Sagnac effect. It has the advantages of an all-solid-stat...

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Problems solved by technology

[0014] The key to the hardware-in-the-loop simulation test scheme is that the time difference between two beams of counter-propagating light passing through the disturbance is the delay time τ, but the delay time τ is generally very small, only on the order of μs. When measuring low frequencies, the added external signal frequency is small , the change is relatively slow, and the change is not obvious within the time of μs. Due to the reciprocity of the optical fiber gyro optical path, the disturbance at low frequencies has no obvious change in the phase, which can only be improved by increasing the amplitude of the disturbance. Therefore, in Low frequency band is not easy to measure frequency characteristics with equivalent input

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