Method for preparing an optical fibre, optical fibre and use of such

US7171093B2 · kind B2 · utility

Assignee

• OPTOPLAN AS · NO

Inventors

• Jon Thomas Kringlebotn · Trondheim, NO
• Audun Hordvik · Trondheim, NO

Key dates

• Filing date: Jun 11, 2002
• Grant date: Jan 30, 2007
• Expiry date: Dec 19, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B6/02395
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Methods for coating an optical fiber with optical fiber Bragg grating (FBG) with a hermetic coating, particularly a coating of carbon, are employed to avoid ingress of gases, vapors or fluids in the ambient environment. This ingress can be from water or hydrogen, which can diffuse in the fiber glass and cause deviation/drift in the measured Bragg measurements. Bragg gratings that maintain the grating strength at temperatures in excess of 1000° C. are used and can be formed by heating the fiber above 1000° C. in a chamber with a reactive gas that produces deposition of carbon.