An optical fiber preform dehydration process and an optical fiber

Abstract

The invention provides an optical fiber preformed rod dehydrating technology. The technology comprises the following steps: A) producing a core rod loose body sequentially comprising a core layer loose body, a silica barrier layer and a cladding layer loose body from inside to outside through adopting a VAD method with a hollow glass tube as a target rod, wherein the hollow glass tube comprises a hollow tube body and an open deposition tip in communication with the end of the hollow tube body, and the core layer loose body is connected with the deposition tip; B) allowing dehydrating atmosphere to go through the hollow glass tube, enter the core layer loose body and penetrate inward from the outside of the cladding layer loose body to dehydrate the core rod loose body in order to obtain a dehydrated core rod loose body; and C) sequentially carrying out sintering, extension and etch washing on the dehydrated core rod loose body, and forming an outer cladding layer on the surface to obtain the preformed rod.

Description

technical field [0001] The invention belongs to the field of optical fiber technology, and in particular relates to a dehydration process of an optical fiber preform rod and an optical fiber. Background technique [0002] The characteristic of VAD method to produce optical fiber core rod is that the core cladding layer is formed at one time. 2 , the cladding needs to be doped with F elements for reducing the cladding refractive index. However, the F element doped into the cladding is extremely active, and it is likely to diffuse into the core layer during deposition or sintering, so the purpose of producing ultra-low attenuation optical fibers cannot be achieved. In order to prevent the diffusion of cladding F to the core layer during deposition, a layer of SiO with higher density is artificially added at the core-clad interface. 2 The barrier layer prevents the diffusion of F into the core layer. A qualified ultra-low attenuation optical fiber core rod is obtained by deh...

AI Technical Summary

Problems solved by technology

However, when the loose body enters the dehydration and sintering process, it is also because the density of the barrier layer is too high, and the dehydration atmosphere cannot pass through, resulting in insufficient dehydration atmosphere in the loose body of the core layer, and the -OH in the loose body of the core layer cannot be removed. The obtained optical fiber has an attenuation loss of 2dB / km at 1383nm, which is much higher than the loss of 0.3dB / km at 1383nm for conventional G.652D optical fiber

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