A polarization non-reciprocal error elimination method in dual polarization fiber optic gyroscope and dual polarization fiber optic gyroscope

Abstract

The invention discloses a polarization non-reciprocal error elimination method in a dual-polarization fiber optic gyroscope and a dual-polarization fiber optic gyroscope. The method is as follows: respectively input the light source into two Y waveguides through a circulator, and input the signal modulated by the Y waveguide into a polarization beam splitting end of two polarization beam splitting beam combiners at the two output ends of each Y waveguide; The polarization beam combining ends of the two polarization beam splitters and beam combiners are connected through a polarization maintaining fiber ring; each of the circulators is connected to a photodetector for collecting the interference signal output by the Y waveguide; wherein, The phases of the modulation signals applied on the two Y waveguides are opposite; the interference signals collected by the two photodetectors are demodulated by using the harmonic demodulation method in the open-loop gyroscope. Based on the structure of the existing dual-polarization fiber optic gyroscope, the invention can greatly reduce the non-reciprocal error caused by polarization cross-coupling, so that both polarization states of the dual-polarization fiber optic gyroscope can be used.

Description

technical field [0001] The invention belongs to the technical field of gyroscopes, and in particular relates to a method for eliminating polarization non-reciprocal errors in a dual-polarization optical fiber gyroscope. Background technique [0002] A gyroscope is a rotational sensor used to measure the rotational angular velocity of the carrier on which it is mounted. Gyroscopes are widely used in the guidance of aircraft and weapons, precision measurement in industry and military, and other fields. The early gyroscopes were mechanical gyroscopes. Mechanical gyroscopes are directional devices manufactured using the physical principle that the rotating shaft of a high-speed rotating body has a tendency to maintain its direction. Since the mechanical gyroscope contains moving parts (such as a high-speed rotor), its structure is complex, its process requirements are high, and its accuracy is restricted in many ways. [0003] In the 1960s, with the advent of lasers, the resea...

AI Technical Summary

Problems solved by technology

The difference between this fiber optic gyroscope and the traditional fiber optic gyroscope is that the optical compensation effect of the two polarization states in the fiber optic ring is used for measurement. Polarization state, there will be a large polarization cross-coupling. Therefore, the polarization non-reciprocity error in the dual-polarization fiber optic gyro is much larger than that of the traditional single-polarization minimum reciprocity structure fiber optic gyroscope. How to reduce the polarization non-reciprocity has become a dual-polarization fiber optic gyroscope. One of the main challenges of the gyroscope

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