Preparation method of optical fiber preform

Abstract

The invention discloses a preparation method of an optical fiber preform. The method comprises the following steps: (1) adopting the vapor axial deposition (VAD) technology to prepare an optical fibre mandrel, adopting the plasma chemical vapor deposition (PCVD) to prepare a fluorine-doped sunken coating; (2) using the optical fibre mandrel and fluorine-doped sunken coating prepared in the step (1) to perform melt polycondensation and obtain an optical fibre mandrel preform; and (3) installing the optical fibre mandrel preform on an outside vapor deposition (OVD) lathe to perform the deposition of an outside coating, and sintering to obtain a transparent optical fiber preform after the deposition. By adopting the method of the invention, the manufacturing efficiency of the bending insensitive single mode fiber preform can be greatly increased, the production cost can be reduced, the large-scale production is easy to popularize and the requirements of the high-speed broadband access network on the development of the bending insensitive single mode fiber can be met; and the deposition efficiency of fluorine can be increased, the sinking depth of the fluorine deposition coating can be increased and the bending resistance of optical fibre can be significantly increased.

Description

technical field [0001] The invention relates to the field of optical fiber communication, in particular to a method for manufacturing an optical fiber preform. Background technique [0002] In contemporary communication networks, client-oriented access technology has always been a difficulty that limits the rapid development of high-bandwidth services. This is the so-called last mile problem in communication networks. After massive information reaches the access network via transmission equipment, Must be broken down into a trickle of streams to be interconnected with end users. For the optical fiber communication network that has accounted for more than 80% of the global information flow, the optical fiber access technology is a natural means to solve this problem. Using the massive bandwidth of optical fiber, through a series of technical means, the "fiber opticization" of the entire information network will be realized, which will fully support the explosive growth of ne...

AI Technical Summary

Problems solved by technology

[0024] In summary, in the process of manufacturing this bend-insensitive curved single-mode optical fiber preform, the conventional process has the following defects: the conventional VAD (axial vapor deposition) process, OVD (outside vapor deposition) process and APVD ( Plasma-enhanced vapor deposition) process, when manufacturing optical fiber preforms, during the deposition process, the deposition efficiency of quartz glass doped with fluorine is very low, the doping concentration of fluorine is between 2% and 2.5%, and the fluorine-doped quartz The relative refractive index difference between the glass composite material and the pure quartz glass material at the wavelength of 633nm is within 0%~-0.35%

This low refractive index depressed fiber waveguide cannot provide better photoelectric magnetic field confinement ability, and the bending resistance of the fiber is poor; at the same time, the low fluorine deposition efficiency not only causes waste of fiber raw materials, but also improves The manufacturing cost of optical fiber preform makes the performance of optical fiber not guaranteed

Using the PCVD (Plasma Chemical Vapor Deposition) process, fluorine doping has a high deposition efficiency, but the deposition rate of the optical fiber core rod manufactured by the PCVD process is too low, and the current maximum rate is between 2.5g / min and 4.5g / min, and The PCVD process belongs to the in-tube deposition process. The size of the deposited fiber core rod is limited by the cavity. The diameter of the fiber core rod is small, the production efficiency is low, the manufacturing cost is high, and it does not have the competitiveness of large-scale production.

Images