Device and method for suppressing polarization error of y-waveguide loop of optical fiber current transformer

Abstract

The invention provides a polarization error suppression device and method for a Y waveguide loop of an optical fiber current transformer, belonging to the technical field of optical fiber sensing. The Y waveguide loop is realized through the Y waveguide phase modulator and the polarization beam splitter. The two output pigtails of the Y waveguide phase modulator are respectively connected to the two input pigtails of the polarization beam splitter through melting point 1 and melting point 2, and are connected through melting point 1. The two pigtails and the two pigtails connected by the melting point 2 respectively constitute the two arms of the Y waveguide loop. The two arms of the Y waveguide loop are not equal in length, and the arm length difference is △L. The input pigtail of the Y waveguide phase modulator is connected with the circulator, and the output pigtail of the polarization beam splitter is connected with the polarization maintaining delay fiber ring. The invention can further reduce the optical path loss, reduce the shot noise of the detector, and improve the small current measurement accuracy of the transformer; by suppressing the polarization error of the Y waveguide loop, the stability of the small current measurement accuracy can be further improved.

Description

technical field [0001] The invention relates to a polarization error suppression device and method for a Y waveguide loop of an optical fiber current transformer, and belongs to the technical field of optical fiber sensing. Background technique [0002] The all-fiber optic current transformer based on the Faraday effect is recognized as a substitute for the traditional electromagnetic induction current transformer due to its principle advantages. Under the background of the country's vigorous development of UHV and smart grids, optical fiber current transformers, as a symbolic component of smart grids, have been equipped and applied on a small scale. Constrained by factors such as optical path noise and digital quantization noise, the accuracy and stability of small current measurement It is difficult to meet the needs of metrology applications, which has become the main technical bottleneck restricting its application in the field of metrology equipment. [0003] The mains...

AI Technical Summary

Problems solved by technology

The reason is: the Y-waveguide loop formed by the Y-waveguide phase modulator and the coupler input pigtail can be equivalent to an M-Z interferometer or a Sagnac interferometer, which is sensitive to vibration and rotation effects and affects the stability of the measurement accuracy of the transformer

[0014] b) The polarization error of the Y waveguide loop has a great influence on the measurement accuracy of the transformer

[0015] At present, there is no research on the polarization characteristics and suppression technology of the Y-waveguide loop of the fiber optic current transformer

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