Polarization crosstalk estimation and symmetry estimation method of optical fiber ring

Abstract

The invention discloses a polarization crosstalk estimation and symmetry estimation method of an optical fiber ring. Polarization coupling strength distribution data of a polarization maintaining optical fiber are obtained by using a coherent domain polarization detection technology, double refraction dispersion coefficients of an optical fiber to be measured are obtained by using a wavelength scanning method, a polarization crosstalk estimation model is established, a method for judging a midpoint of the optical fiber ring is provided, polarization crosstalk data of the left and right sides of the midpoint are obtained, the polarization crosstalk of the left and right sides of the midpoint is respectively determined, and the symmetry of the optical fiber to be measured is analyzed. The polarization crosstalk estimation and symmetry estimation method of the optical fiber ring is simple in design structure, high in comprehensiveness, high in measuring accuracy and high in reliability, the polarization crosstalk of the optical fiber ring can be measured during measurement of the polarization coupling strength distribution of the optical fiber ring, and a polarization crosstalk value serves as a reference index for evaluating ring symmetry. The method can be widely applied to measurement of various polarization maintaining optical fibers and a novel photonic crystal optical fiber, optical fibers for a gyroscope can be optimally selected, and the method plays an important role in evaluation and guidance optimization of the temperature performance of an optical fiber gyroscope.

Description

technical field [0001] The invention relates to the detection technology of an optical fiber ring for a polarization-maintaining optical fiber gyroscope, and proposes a model for estimating the polarization crosstalk of the optical fiber ring by using the polarization coupling intensity distribution data measured by white light interferometry, and especially proposes a symmetry evaluation scheme of the optical fiber ring. Background technique [0002] Fiber optic gyroscope is a high-precision inertial instrument that uses the Sagnac effect to measure angular velocity. It has a simple structure, can adapt to different precision requirements, and has good environmental adaptability. It is a new type of all-solid-state inertial device and will become the main instrument in the inertial navigation and strategic application fields. [0003] The use of polarization-maintaining fiber reduces the influence of parasitic birefringence caused by external factors such as environmental c...

AI Technical Summary

Problems solved by technology

During winding, it is necessary to detect and correct some defects such as fiber stacking and crossover in time, otherwise it will seriously affect the performance of the fiber ring, and the methods of online detection of winding are mainly video monitoring, tension monitoring and other means, which can only indirectly reflect the winding quality, unable to directly monitor the impact of the winding process on fiber performance

Using distributed sensing to detect the fiber ring, the more traditional method is to use the Brillouin Optical Time Domain Reflectometer (BOTDR) to detect the stress of the fiber ring, but the spatial resolution and sensing sensitivity of this method are low, and it is difficult to accurately monitor the fiber online. ring quality

Existing methods are also difficult to realize the thermal stress detection of finished products after optical fiber wrapping

[0005] A white light interferometer can be used to measure the polarization coupling intensity with high precision, but at present, the distribution can only be observed intuitively, and there is a lack of a quantitative evaluation method to analyze the symmetry of the fiber ring, and it is also lacking in the analysis of the full temperature characteristics of the ring. Valid Evaluation Criteria

Moreover, the traditional optical fiber ring extinction ratio tester needs precise alignment operation, which is only used as an auxiliary part of the white light interferometry analysis, and at the same time, it cannot quantitatively measure the polarization crosstalk of a certain part of the fiber ring according to the specific conditions of the ring-wrapping process.

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