Fusion shrinkage preparation method of core rod of optical fiber preform rod

Abstract

The invention relates to a fusion shrinkage preparation method for preparing a core rod of an optical fiber preform rod through fusion shrinkage of a doped quartz liner tube. According to the fusion shrinkage preparation method of the core rod of the optical fiber preform rod, the deposited doped quartz liner tube is mounted on a fusion shrinkage lathe. The fusion shrinkage preparation method of the core rod of the optical fiber preform rod is characterized by comprising the following steps: enabling the doped quartz liner tube to rotate at a rotation speed being 15-30rad/min, supplying a heat source for fusion shrinkage by taking a heating furnace sleeve as a heating device, heating at the temperature of 1900 to 2250 DEG C, enabling the heating furnace sleeve to move forth and back from one end to the other end of an axial liner tube of the doped quartz liner tube, carrying out gradual fusion shrinkage on the doped quartz liner tube and finally firing; and sealing two ends of the doped quartz liner tube and introducing mixed gas for corroding the inner wall of the liner tube in the fusion shrinkage process. By virtue of the fusion shrinkage preparation method of the core rod of the optical fiber preform rod, an F-containing compound high in reactivity is taken as the lining corrosion gas; the fusion shrinkage and corrosion are carried out synchronously, so that the reduction of a refractive index of a core layer can be effectively avoided, the time for producing the core rod of the preform rod can be greatly reduced, the processing efficiency and the efficiency of using the device can be improved, the production cost of the optical fiber preform rod can be reduced, and the stability of the optical fiber water peak can be guaranteed, therefore the quality of the optical fiber processing is improved.

Description

technical field [0001] The invention relates to a preparation method for melting and shrinking a doped quartz liner into an optical fiber prefabricated core rod, and belongs to the technical field of optical fiber manufacturing. Background technique [0002] Currently known manufacturing processes for optical fiber preforms typically include in-pipe vapor deposition processes, such as MCVD (modified chemical vapor deposition) and PCVD (plasma chemical vapor deposition) plasma-induced chemical vapor deposition methods, as well as tube External vapor deposition process, such as OVD (outside vapor deposition) external vapor deposition process and VAD (vapor axial deposition) external axial deposition process. [0003] The preparation of optical fiber preform rods (core rods) by the in-tube deposition method requires melting the deposited doped silica liner to obtain a solid rod. The process of melting and shrinking is carried out at a temperature higher than the softening temp...

AI Technical Summary

Problems solved by technology

This method can reduce the volatilization of dopants in the sintering pass due to the increase in the pore size of the preform tube, but because the pore size is small at this time and there is only one pass of corrosion, there is a risk of insufficient corrosion. The place where the furnace travels to the return point will be more obvious due to the faster moving speed of the heat source (to avoid repeated heating and burning).

At the same time, the lower amount of corrosion can easily make the mandrel water peak unstable

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