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 means 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 infra-red, visible or ultra-violet 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