Polarization-preserving fiber axis fixing method based on spatial diffraction light

Abstract

The invention discloses a polarization-preserving fiber axis fixing method based on spatial diffraction light, which comprises the following steps: (1) vertically irradiating laser beams to polarization-preserving fibers to form a back diffraction image; (2) clearly shooting part of the diffraction image with obviously strong light intensity in the diffraction image by using a CCD camera with a lens, and transmitting the part of the diffraction image to an image processor; (3) acquiring symmetric coefficients of the diffraction image; (4) rotating the polarization-preserving fibers to acquirethe diffraction images corresponding to different azimuth angles of the polarization-preserving fibers and acquire a corresponding relation curve of the azimuth angles of the polarization-preserving fibers and the symmetric coefficients; and (5) selecting two wave crests of the curve of which symmetric coefficient is more than 0.96 and of which azimuth angle is adjacent 90 degrees, and judging the wave crests and the azimuth angles corresponding to a quick axis and a slow axis according to the diversity of the diffraction images of the quick axis and the slow axis of the polarization-preserving fibers so as to achieve axis fixation, wherein one wave crest corresponds to the quick axis, and the other wave crest corresponds to the slow axis. The method does not need to establish a standard curve, and is quick to fix the axis.

Description

technical field [0001] The invention relates to a method for fixing an axis of a polarization-maintaining optical fiber. Background technique [0002] The existing polarization-maintaining optical fiber axis fixing method mainly uses image processing technology to obtain the characteristic curve and characteristic map of any azimuth angle, and then interacts the curve or characteristic map with the standard curve library or the curve or pattern in the standard library. Correlation, the angle corresponding to the maximum value of the cross-correlation is the azimuth angle of the polarization axis to be obtained. [0003] Chinese invention patent ZL200610122819.0 discloses a polarization-maintaining optical fiber axis fixation method based on spatially diffracted light, which collects the back diffraction image of spatially diffracted light to solve the axis-fixing problem of polarization-maintaining optical fiber, and based on the image feature quantity or The feature quanti...

AI Technical Summary

Problems solved by technology

In practice, it is difficult to establish a standard curve, which limits the promotion of this axis-fixing method

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