Apparatus and method for measuring strain in optical fibers using rayleigh scatter

US6545760B1 · kind B1 · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Mark E. Froggatt · Blacksburg, US
• Jason P. Moore · Vancouver, US

Key dates

• Filing date: Mar 24, 2000
• Grant date: Apr 8, 2003
• Expiry date: Mar 24, 2020

Classification

• Technology area (CPC G): Physics
• CPC primary: G01K11/32
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An apparatus and method for measuring strain in an optical fiber using the spectral shift of Rayleigh scattered light. The interference pattern produced by an air gap reflector and backscattered radiation is measured. Using Fourier Transforms, the spectrum of any section of fiber can be extracted. Cross correlation with an unstrained measurement produces a correlation peak. The location of the correlation peak indicates the strain level in the selected portion of optical fiber.