Process of making rare earth doped optical fibre

Abstract

The present invention discloses a method for manufacturing rare earth (RE) doped optical fibers by using silica nanoparticles coated with rare earth oxides as a precursor material. More specifically, the method of the present invention includes the following steps: A stable dispersion (sol) of silica nanoparticles coated with a rare earth oxide is prepared at ambient temperature; the inner surface of a silica glass tube is coated with the silica nanoparticles using a dip coating technique or any other conventional method. A thin coating of silica sol containing appropriate dopants selected from Ge, Al, P, etc.; then using MCVD technology to make a preform of optical fiber, and then forming an optical fiber of desired shape. The novelty of the present invention is that when forming the fiber core, the step of forming a loose powder layer at high temperature in the fused silica glass tube in the CVD process is omitted, and the introduction of rare earth ions into the loose powder layer by solution doping technology or other methods is omitted. The step in the powder layer, the direct addition of rare earth oxides in the sol avoids the formation of rare earth ion crystallites and clusters, and prevents compositional changes including changes in the concentration of rare earths in the core, thereby greatly increasing the process reproducibility and reliability, in addition, at ambient temperature the Ge(OET) 4 The addition of silica sol above reduces the GeCl required to achieve the desired numerical aperture at high temperature 4 amount.

Description

technical field [0001] The invention relates to a method of manufacturing rare earth doped optical fiber. Background technique [0002] Optical fibers based on high-purity silica have been identified as the most efficient interconnection media for optical telecommunication networks. Such optical fibers can be used as passive transmission media to guide the long-distance transmission of optical signals. However, if rare earth (RE) ions are doped into the core of such fibers, the fibers are optically active because the rare earths are pumped at appropriate wavelengths to produce characteristic emissions. Because of the aforementioned properties, rare earth-doped fibers show great potential as active devices for photonic devices such as optical amplifiers and fiber lasers at various wavelengths. It has also been found that such fibers are expected to be used as sensors for monitoring temperature and radiation dose, among other things. [0003] Erbium-doped fiber is the activ...

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Problems solved by technology

[0025] 3. It is difficult to control the porosity of the deposited green layer because it is particularly sensitive to the deposition temperature, the speed at which the burner moves back and forth, and the flow of reaction raw materials

[0033] 11. Since the process is sensitive to parameters during various processing stages such as deposition, solution doping, drying and sintering, it is not reliable and reproducible

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