A kind of manufacturing method of pure silicon core low loss optical fiber

Abstract

The invention discloses a making method of pure silica core low-loss optical fibers. The method comprises the steps that etching is conducted on the inner wall of a fluorine-doped sedimentation tube; silicon dioxide is deposited in the fluorine-doped sedimentation tube, vitrification is conducted, and a silica core layer is formed; the fluorine-doped sedimentation tube provided with the silica core layer is subjected to melting contraction to obtain a solid core rod, wherein the fluorine-doped sedimentation tube forms inner cladding; silica is deposited outside the core rod to form outer cladding, and a pure silica core optical fiber preform rod is made; the pure silica core optical fiber preform rod is subjected to wire drawing, and the pure silica core low-loss optical fibers are made. According to the making method of the pure silica core low-loss optical fibers, fluorine can be prevented from being dispersed into the core layer, the OH<-> content of the core layer can be prevented from exceeding the standard, and the performance of drawing optical fibers is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of optical fiber manufacturing, in particular to a method for manufacturing a pure silicon core low-loss optical fiber. Background technique [0002] Optical fiber preforms are the raw materials for drawing optical fibers, including a core layer and a cladding layer with a lower refractive index. Among them, SiO 2 It is the main glass former used to make optical fiber preforms, and its refractive index can be changed by doping to form a waveguide structure. In the prior art, GeO is generally doped into the core layer 2 , so that the refractive index of the core layer is higher than that of the cladding pure silica glass. The relative difference between the refractive index of the core layer and the cladding layer is expressed by the relative refractive index difference Δ, and the refractive indices of the core layer and the cladding layer are respectively n 1 and n 2 , the value of the relative refracti...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the loose body in the dehydration and doping process is hollow, and the OH- produced by the hydrolysis reaction and the fluorine element in the fluorine doping process are more likely to enter the hollow in the middle of the loose body, and then diffuse into the core layer, causing the fluorine element Doping failure; after the end of vitrification, the central hole must be sealed by longitudinal equipment, which will also cause OH in the core layer - The content exceeds the standard, which will further affect the performance of the fiber after drawing

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