BILLET FOR ULTRA-LOW LOSS FIBER AND FIBER OBTAINED BY A VAPOR PHASE AXIAL DEPOSITION METHOD Russian patent published in 2020 - IPC C03B37/02 

FIELD: manufacturing technology.

SUBSTANCE: present invention discloses ultra-low loss fibers. Viscosity of the core layer can be reduced by introducing an alkali metal in the axial deposition from the vapor phase (VPAD) such that the core layer is better aligned with the inner shell and the outer shell, wherein inner voltage is also reduced; as a result, it becomes possible to obtain a fiber with ultra-low losses and low transmission attenuation. Method of producing ultra-low loss fibers according to the present invention is a conventional VPAD deposition process; common deposition process is not significantly affected by low content of alloying alkali metal and low air flow during deposition; doping with alkali metal during precipitation is carried out so as not to increase duration of production and, thus, to ensure stable production in simple production process, which can be used for mass production.

EFFECT: according to the present invention, attenuation in the fiber can be optimized according to the ultra-low loss standard so that a number of relay stations can be reduced, costs can be reduced and quality of transmission can be improved during high-speed transmission over long distances with low attenuation.

10 cl, 3 dwg