OPTICAL FIBER AND METHOD OF ITS PRODUCTION Russian patent published in 2020 - IPC C03B37/18 

FIELD: manufacturing technology.

SUBSTANCE: present invention provides a method of making optical fiber. In present invention, when depositing unbound mass of core layer and unbound mass of shell layer, hydrogen-oxygen flame is used to increase temperature of interface between core layer and layer of shell, as a result of which the silicon dioxide at the interface is appropriately compacted to form an insulation layer with a relatively high density, and wherein the insulation layer can effectively prevent diffusion of the element F from the layer of the shell into the unbound mass of the core, such that the difference between the refractive index of the core layer and the refractive index of the layer of the shell complies with the requirement to thereby ensure the production of an ultra-low attenuation optical fiber. Besides, in the present invention, the hollow glass tube is used as a seed rod, and at that, the hollow glass tube, which is a seeding rod, is directly connected to the unbound mass of the core layer. During the subsequent dehydration, the dehydration medium not only penetrates from the outside into the unbound mass of the shell layer from the outside, but also the medium for dehydration directly enters the core layer through the hollow glass tube. Thus, even if the external medium for dehydration can not penetrate into the core layer, hydroxyl groups in the core layer can be removed to thereby reduce the water peak.

EFFECT: invention discloses an optical fiber and a method for production thereof.

15 cl, 6 dwg, 2 tbl