OPTICAL INTERROGATOR FOR PERFORMING INTERFEROMETRY USING FIBER BRAGG GRATINGS

Register USPTO Patent
Application Number 17521052
Status Pending
Filing Date 2021-11-08
First Publication Date 2022-02-24
Publication Date 2022-02-24
Owner Hifi Engineering Inc. (Canada)
Inventor
  • Moore, Brian H.
  • Shakespeare, Walter Jeffrey
  • Wallace, Phillip William
  • Hoang, Viet
  • Henrikson, Chris
  • Sandhu, Ajay
  • Dumitru, Adrian
  • Clement, Thomas
  • Huang, Dongliang
  • Jalilian, Seyed Ehsan

Abstract

There is described a method for interrogating optical fiber comprising fiber Bragg gratings (“FBGs”), using an optical fiber interrogator. The method comprises (a) generating an initial light pulse from phase coherent light emitted from a light source, wherein the initial light pulse is generated by modulating the intensity of the light; (b) splitting the initial light pulse into a pair of light pulses; (c) causing one of the light pulses to be delayed relative to the other of the light pulses; (d) transmitting the light pulses along the optical fiber; (e) receiving reflections of the light pulses off the FBGs; and (f) determining whether an optical path length between the FBGs has changed from an interference pattern resulting from the reflections of the light pulses.

IPC Classes  ?

  • G01B 11/16 - Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
  • G01D 5/353 - Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
  • G01H 9/00 - Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
  • G01K 11/3206 - Measuring temperature based on physical or chemical changes not covered by group , , , or using changes in transmittance, scattering or luminescence in optical fibres at discrete locations in the fibre, e.g. using Bragg scattering
  • G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis