Optical fiber preform and manufacture method thereof

Abstract

The invention provides a manufacture method of an optical fiber preform, comprising the steps: providing a core layer, and precipitating a first inner coating layer and a second inner coating layer sequentially on the surface of the core layer; soaking the core layer with the first and second inner coating layers in a heating zone in suspended manner, and carrying out dehydroxylation and vitrification sintering to form a quartz glass rod; forming an outer coating layer on the surface of the quartz glass rod to obtain the optical fiber preform. The optical fiber preform herein has large size and good fluorine-doping control precision for a recessed layer, has bending performance under small radius R of < / =5 mm, has low fiber attenuation and good color dispersion, has zero-color-dispersion wavelength of < / =1320 nm and low hydroxy content, and meets the indicator of ITU-TG657B3 and higher.

Description

technical field [0001] The invention belongs to optical communication technology, and in particular relates to an optical fiber preform rod and a manufacturing method thereof. Background technique [0002] With the continuous development of optical fiber transmission technology, fiber-to-the-home has become an important direction of communication access network construction. In the actual laying of FTTx optical fiber lines, it is often necessary to carry out optical fiber laying operations in small or narrow spaces, especially the invisible optical cables and FTTD (fiber to the table) that have appeared in recent years. At this time, the optical fiber should have a high bending resistance in a small bending radius. Therefore, it is necessary to design, develop and manufacture bend-insensitive optical fibers with better performance to meet the requirements of FTTx network construction and device miniaturization. According to the ITU-T G.657 optical fiber standard that is no...

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Problems solved by technology

[0006] 1. The in-tube deposition method (MCVD, PCVD) is limited by the process conditions and size, the water peak absorption attenuation is large, and the manufacturing cost is high, and the size of the preform is small, so it cannot be scaled up;

[0007] 2. In the currently used VAD manufacturing core rod process, the known patents CN2010106090.0, CN201210243973.9, US5032001, US7043125b2, CN176680, CN104991306 patents improve the macrobending performance of the optical fiber to a certain extent by realizing the design of the lower concave layer , when the bending radius is less than or equal to 10mm, the macrobending performance cannot meet the requirements of G.657.B3; at the same time, it is found that the depth and width of the concave layer will affect the macrobending performance, fiber cut-off wavelength and dispersion performance, so The width and depth of the recessed fluorine-doped layer prepared by traditional VAD cannot be precisely controlled

[0008] 3. In patent CN201310300024.4, the core layer component is SiO 2 -GeO 2 -F-Cl, according to the Rayleigh scattering principle of optical fiber silica glass, the more the core layer is doped, it is not conducive to ensuring the uniformity and consistency of the material, and the attenuation value of the optical fiber is also greater

Although it meets the G.657.B3 attenuation index, it cannot meet the existing market demand. It not only meets the G.657.B3 macrobend, but also meets the G652D attenuation and dispersion index.

At the same time, in the methods disclosed in patents CN201310300024.4, ZL200910062855.6, and CN104991306, only the design method is mentioned, but the manufacturing method of the optical fiber preform is not specifically mentioned. difficult to implement

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