Plasma deposition process for producing an optical preform with a cladding glass layer of fluorine-doped quartz glass

US9487429B2 · kind B2 · utility

Assignee

• HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

• Andreas Schultheis · Langenselbold, DE
• Karsten Bräuer · Bruchköbel, DE
• Richard Schmidt · Hammersbach, DE

Key dates

• Filing date: Jul 26, 2012
• Grant date: Nov 8, 2016
• Expiry date: Mar 27, 2033

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03B2207/66
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

In plasma deposition processes for producing an optical preform according to the POD method, a cladding glass layer composed of fluorine-doped quartz glass is produced by means of a plasma torch on a cylindrical substrate body composed of quartz glass, said substrate body rotating about the longitudinal axis thereof. In this case, the plasma torch performs a reversing relative movement between two turning points (A; B) along the substrate body. In order, proceeding therefrom, to achieve a high fluorine doping in conjunction with a dopant distribution that is as uniform as possible axially, the invention proposes that a heat element has a heating effect on the region of one turning point (A; B) when the plasma torch is situated in the region of the other turning point (B; A).