Difference double-interference type optical fiber gyroscope based on birefringence modulation

Abstract

The invention discloses a difference double-interference type optical fiber gyroscope based on birefringence modulation. The optical fiber gyroscope comprises a light source, a modulator, a coupler, an optical fiber ring, a polarization beam splitter, a first detector and a second detector, wherein the light source and the modulator are welded at a melting point O1 with an angle of 45 DEG; the modulator and a port A of the coupler are welded at a melting point O2 with an angle of 45 DEG; an end C of the coupler and one end of a polarization-maintaining optical fiber ring are welded at a melting point O3 with an angle of 0 DEG; an end D of the coupler and the other end of the optical fiber ring are welded at a melting point O4 with an angle of 90 DEG; an end B of the coupler and an input end of the polarization beam splitter are welded at a melting point O5 with an angle of 0 DEG; and two output ends of the polarization beam splitter are respectively welded to the first detector and the second detector. According to the invention, closed-loop control of the difference double-interference type optical fiber gyroscope is realized; and a wide-spectrum light source with very weak coherent characteristics is adopted, thereby avoiding strong noise brought by various stray wave interferences which are caused by strong coherent characteristics of a laser light source.

Description

technical field [0001] The invention relates to a closed-loop differential double-interference optical fiber gyroscope which realizes SAGNAC effect multiplication and closed-loop control under the condition that the area of ​​the optical fiber ring and the length of the optical fiber are constant, and belongs to the technical field of optical fiber gyroscopes. Background technique [0002] As a new type of inertial angular velocity sensor that is developing extremely rapidly, fiber optic gyroscope has its unique technical and performance advantages, such as all-solid-state structure, high reliability, long life; fast start-up speed, short response time; large measurement range and wide dynamic range ; Anti-shock, vibration, chemical corrosion resistance; small size, light weight, low cost; suitable for mass production, etc., have been widely used in various fields. [0003] The commonly used form of fiber optic gyroscope in the world is the single interference type, that is,...

AI Technical Summary

Problems solved by technology

At present, the differential dual-interference fiber optic gyroscope adopts an open-loop scheme, and the phase difference between the light waves output by each interferometer is very large, so it is necessary to use a laser with good coherence characteristics as a light source to achieve the interference between these light waves. But this leads to interference between various spurious waves, so the open-loop differential dual-interferometric fiber optic gyroscope is noisy and difficult to suppress

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