Optical sensor device having creep-resistant optical fiber attachments

US6768825B2 · kind B2 · utility

Assignee

• Weatherford/Lamb, Inc. · US

Inventors

• Robert J. Maron · Cromwell, US
• Guy A. Daigle · Plainville, US
• James Dunphy · South Glastonbury, US
• Thomas Engel · Munich, DE
• John J. Grunbeck · Northford, US
• Mark R. Fernald · Enfield, US

Key dates

• Filing date: Jun 1, 2001
• Grant date: Jul 27, 2004
• Expiry date: Dec 8, 2021

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B6/3854
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A method and device for pressure sensing using an optical fiber having a core, a cladding and a Bragg grating imparted in the core for at least partially reflecting an optical signal at a characteristic wavelength. The cladding has two variation regions located on opposite sides of the Bragg grating to allow attachment mechanisms to be disposed against the optical fiber. The attachment mechanisms are mounted to a pressure sensitive structure so as to allow the characteristic wavelength to change according to pressure in an environment. In particular, the variation region has a diameter different from the cladding diameter, and the attachment mechanism comprises a ferrule including a front portion having a profile substantially corresponding to at least a portion of the diameter of the variation region and a butting mechanism which holds the ferrule against the optical fiber.