Method for manufacturing polarization-preserving optical fiber

Abstract

The invention discloses a method for manufacturing a polarization-preserving optical fiber, which relates to the field of manufacturing of optical fibers. The method comprises the following steps of: S1, manufacturing a polarization-preserving core rod and two boron-doped stress rods by adopting a PCVD (Plasma Chemical Vapor Deposition) process, wherein the polarization-preserving rod is provided with a core and a coating layer; S2, melting the polarization-preserving rod by using a quartz casing at the high temperature of 2,000-2,200 DEG C, and finely drawing to obtain a polarization-preserving parent rod; S3, longitudinally processing a pair of symmetrical circular holes in both sides of the central line of the polarization-preserving parent rod, wherein the central lines of the circular holes and the central line of the polarization-preserving parent rod are parallel to each other and are positioned in the same plane; S4, embedding the two boron-doped stress rods into the two circular holes to construct a polarization-preserving optical fiber prefabricated rod; and S5, drawing the polarization-preserving optical fiber prefabricated rod into a polarization-preserving optical fiber in a molten state, wherein in the polarization-preserving optical fiber, the ratio of the distance between the inner edge of each boron-doped stress rod close to the core and the center of the core to the radius of the core is 2.0-4.0. The method has the advantages of simple and convenient process, low manufacturing cost, high axial uniformity and contribution to mass production.

Description

technical field [0001] The invention relates to the field of optical fiber preparation, in particular to a method for preparing a polarization-maintaining optical fiber. Background technique [0002] Polarization Maintaining Optical Fiber (Polarization Maintaining Optical Fiber) is referred to as polarization maintaining fiber (PMF). Due to the introduction of birefringence into the fiber, the difference in the propagation constants of the merged HEx11 and HEy11 two orthogonal modes increases, and the coupling probability of the two modes decreases. Therefore, the linearly polarized light can maintain its polarization state for transmission in the optical fiber. With the in-depth development of amplitude modulation to phase and polarization state modulation in optical communication systems and optical fiber sensing, fiber optic technology has made progress. The linear polarization-maintaining ability of polarization-maintaining fiber makes polarization-maintaining fiber val...

AI Technical Summary

Problems solved by technology

[0005] First: Because the hardness of the quartz glass preform is very high, the depth and diameter of the hole are limited. The hole depth is generally about 150mm, and high-precision mechanical finishing is required, which is costly and will also have some impact on the strength of the optical fiber. influences

[0006] Second: limited by the size of boron-doped stress rods and holes, the diameter of generally perforated combined optical fiber preforms is relatively small, and the production length of a single optical rod is less than 40km, which is unfavorable for large-scale production

[0007] Third: Affected by the processing accuracy, the double holes processed by the traditional drilling method need to be polished to meet the downstream process requirements, which increases the process cost

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