Patent ID: 9085481
Filing Date: 2015-07-21
Classification: C03B,C03C,G02B,Y10T

Abstract:
1. A method for producing an optical fiber, said method comprising: providing a quartz glass preform or a coaxial assembly of quartz glass components; and elongating said preform or coaxial assembly so as to form the optical fiber; the fiber comprising wherein the preform or coaxial assembly includes the quartz glass of the ring zone in the form of a ring zone tube consisting of quartz glass with a mean fluorine content of at least 6000 wt. ppm, said ring zone tube having a wall defined by an inner tube surface and an outer tube surface, the ring zone tube wall having a radial fluorine concentration profile over a radial thickness of the ring zone tube wall, said profile having an inner fluorine depletion layer with a layer thickness of at least 1 μm and not more than 10 μm, the inner fluorine depletion layer having a near-surface region with a thickness of 1 μm near the inner tube surface, and the inner fluorine depletion layer having a fluorine content that decreases towards the inner tube surface and is not more than 3000 wt, ppm in said near-surface region.