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Title: Optical fiber sensor technique for strain measurement

Laser light from a common source is split and conveyed through two similar optical fibers and emitted at their respective ends to form an interference pattern, one of the optical fibers having a portion thereof subjected to a strain. Changes in the strain cause changes in the optical path length of the strain fiber, and generate corresponding changes in the interference pattern. The interference pattern is received and transduced into signals representative of fringe shifts corresponding to changes in the strain experienced by the strained one of the optical fibers. These signals are then processed to evaluate strain as a function of time, typical examples of the application of the apparatus including electrodeposition of a metallic film on a conductive surface provided on the outside of the optical fiber being strained, so that strains generated in the optical fiber during the course of the electrodeposition are measurable as a function of time. In one aspect of the invention, signals relating to the fringe shift are stored for subsequent processing and analysis, whereas in another aspect of the invention the signals are processed for real-time display of the strain changes under study.
Authors:
 [1] ;  [1]
  1. (Albuquerque, NM)
Publication Date:
OSTI Identifier:
867015
Report Number(s):
US 4841778
DOE Contract Number:
AC04-76DP00789
Resource Type:
Patent
Research Org:
AT & T CORP
Country of Publication:
United States
Language:
English
Subject:
optical; fiber; sensor; technique; strain; measurement; laser; light; common; source; split; conveyed; similar; optical; fibers; emitted; respective; form; interference; pattern; optical; fibers; portion; subjected; strain; changes; strain; changes; optical; path; length; strain; fiber; generate; corresponding; changes; interference; pattern; interference; pattern; received; transduced; signals; representative; fringe; shifts; corresponding; changes; strain; experienced; strained; optical; fibers; signals; processed; evaluate; strain; function; time; typical; examples; application; apparatus; including; electrodeposition; metallic; film; conductive; surface; provided; outside; optical; fiber; strained; strains; generated; optical; fiber; course; electrodeposition; measurable; function; time; aspect; signals; relating; fringe; shift; stored; subsequent; processing; analysis; aspect; signals; processed; real-time; display; strain; changes; study; signals representative; interference pattern; interference pattern; interference pattern; path length; optical fibers; optical fibers; optical fibers; optical fiber; optical fiber; optical fiber; optical fiber; optical fiber; optical fiber; laser light; optical path; apparatus including; common source; corresponding change; similar optical; subsequent process; metallic film; conductive surface; fiber sensor; rate corresponding /73/204/