Method for preparing optical fiber preform rod

Abstract

The invention relates to a method for preparing optical fiber preform rod, which comprises the following steps: directly coating a uniform quartz loose body on an external surface of a core rod by using silane or siloxane as a raw material through an external vapor deposition method so as to form a loose-body preform rod, slowing heating the loose-body preform rod at a high temperature for dehydration, and sintering the loose-body preform rod to obtain a transparent optical fiber preform rod. The invention adopts clean silane or siloxane as a raw material for forming the quartz coating, does not generate a lot of harmful hydrogen chloride, overcomes the disadvantage that chlorine-containing raw material introduces single bonds which can block atomic bonds into the coating, increases the purity and strength of the preform rod material, and improves the mechanical strength of optical fibers.

Description

technical field [0001] The invention relates to a method for preparing an optical fiber prefabricated rod. The method comprises using silane or siloxane as a raw material to directly coat a uniform quartz soot body on the outer surface of a core rod by an external vapor deposition method to form a soot body prefabricated rod, and then Slowly heating the soot preform at high temperature for dehydration and sintering into a transparent optical fiber preform. Background technique [0002] For more than 30 years, the fiber optic manufacturing process has been continuously evolving. Optical fiber preform manufacturing technology is the core technology of the optical fiber industry. At present, the production of commercial preforms generally adopts a "two-step" manufacturing process, that is, the first step is the manufacture of mandrels; the second step is the manufacture and formation of outsourced parts. Among them, the manufacturing process of the core rod typically has an i...

AI Technical Summary

Problems solved by technology

However, this casing method has the following disadvantages: the large-sized casing requires high geometric accuracy, the manufacturing process is complicated, and the material loss during the casing processing leads to an increase in cost.

However, in order to prepare large preforms with low water peaks, the technical route of the extra-tube method + Soot direct outsourcing method also has the following shortcomings: As we all know, the extra-tube method is difficult to achieve complex refractive index profiles and Ge / F co-doping process and other aspects are obviously insufficient compared with the in-tube method, so the process stability is facing a huge challenge

[0007] The vapor deposition method in the prior art all uses SiCl 4 As raw material, SiCl 4 The vapor deposition method will produce highly corrosive and toxic chlorine and hydrogen chloride, the purification process is expensive, and the residual SiCl that does not participate in the reaction 4 It is difficult to recycle by hydrogenation, once it enters the environment, it will have a bad impact, and the polluted land will become barren

[0008] SiCl 4 Depositing quartz glass as a raw material will introduce Si-Cl bonds into the quartz glass material, destroying the original Si-O space network structure, causing the Si-O atomic chain to break, and macroscopically showing that the viscosity of the quartz melt is reduced and the mechanical strength of the optical fiber, which increases the probability of fiber breakage

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