Stress-focusing shaft-alignment panda polarization-maintaining fiber and shaft alignment method thereof

Abstract

The invention relates to a stress-focusing shaft-alignment panda polarization-maintaining fiber and a shaft alignment method thereof. The fiber comprises a fiber core coated at the center of a cladding layer; stress regions are arranged at the cladding layer and are symmetrically arranged at the two sides of the fiber core symmetrically; focusing light-transmission circles are arranged at centers of the stress regions; and the refractive index of the focusing light-transmission circle is higher than that of the stress region. The diameter D1 of the fiber core belongs to (3 micros, 5 microns), the diameter D2 of the cladding layer belongs to (58 microns, 81 microns), the diameter D3 of the stress region belongs to (10 microns, 30 microns), and the diameter D4 of the focusing light-transmission circle at the center of the stress region belongs to (2 microns, 8 microns). According to the fiber and the shaft alignment method thereof, the focusing light-transmission circles will form a bright line at a field of view during spotting, focusing, and alignment process at the side and the bright line can be used for precise alignment.

Description

technical field [0001] The present invention relates to a panda-type polarization-maintaining optical fiber and its alignment method, in particular to a narrow-diameter panda-type polarization-maintaining optical fiber that can accurately and quickly realize alignment with high birefringence performance in the process of fusion splicing and docking of the panda polarization-maintaining optical fiber. An optical fiber and an axis alignment method thereof belong to the technical field of optical fiber. Background technique [0002] Polarization-maintaining fiber, that is, polarization-maintaining fiber, is used to transmit linearly polarized light and is widely used in various fields of national economy such as aerospace, aviation, navigation, industrial manufacturing technology and communication. In the interferometric fiber sensor based on optical coherent detection, The use of polarization-maintaining fiber can ensure that the direction of linear polarization remains unchan...

AI Technical Summary

Problems solved by technology

[0005] The cladding diameters of currently used polarization-maintaining fibers are generally 125 μm and 80 μm. When using panda-type polarization-maintaining fibers in the system, fiber fusion splicing is required to complete the fixed connection of pigtails of different devices. During the fusion splicing process, It is necessary to correspond to the circular stress zones symmetrically distributed on both sides of the fiber core, so as to prevent the polarization crosstalk caused by the crossing of the stress axis and reduce the birefringence consistency of the polarization maintaining fiber; but the refraction of the symmetrical stress zone of the panda-type polarization The efficiency is lower than that of the quartz cladding, so when light is injected from the end face or side for alignment, the stress zone will block the incoming alignment light, affect the field of view of the alignment, and reduce the efficiency and accuracy of the alignment; at the same time When the optical fiber is fused without accurate alignment, the performance deteriorates and needs to be re-spliced, and the end faces of the two optical fibers need to be precisely cut flat, which is very inefficient.

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