Low insertion loss high temperature stable fiber Bragg grating sensor and method for producing same

US11359939B2 · kind B2 · utility

Assignee

• National Research Council of Canada · CA

Inventors

• Dan Grobnic · Ottawa, CA
• Stephen J. Mihailov · Gatineau, CA
• Robert B. Walker · Paradise, US
• Ping Lu · Ottawa, CA
• Huimin Ding · Ottawa, CA
• David COULAS · Ottawa, CA
• Cyril Hnatovsky · Ottawa, CA

Key dates

• Filing date: Nov 19, 2020
• Grant date: Jun 14, 2022
• Expiry date: Nov 19, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B6/34
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Provided is an optical waveguide with an inscribed Bragg grating, where the Bragg grating is stable at high temperature, has low scattering loss and high reflectivity. Also provided is a method for inscribing a Bragg grating in an optical waveguide, the method comprising irradiating the optical waveguide with electromagnetic radiation from an ultrashort pulse duration laser of sufficient intensity to cause a permanent change in an index of refraction within a core of the optical waveguide, where the irradiating step is terminated prior to erasure of a Bragg resonance, and heating the optical waveguide to a temperature and for a duration sufficient to substantially remove a non-permanent grating formed in the optical waveguide by the irradiating step.