×

Microbending of optical fibers for remote force measurement

  • US 4,459,477 A
  • Filed: 08/27/1981
  • Issued: 07/10/1984
  • Est. Priority Date: 08/27/1981
  • Status: Expired due to Term
First Claim
Patent Images

1. A system for monitoring forces acting upon a structure, comprising:

  • a plurality of optical fibers extending along the structure;

    a plurality of sets of force transducers wherein each of said sets is operatively associated with a respective one of said fibers and wherein each of said transducers is mounted on the structure for movement in response to a localized force acting upon the structure to induce microbending of its associated fiber wherein light passing through each of said fibers is abruptly attenuated at each microbend therein;

    means for launching a pulsed optical signal into said fibers for passage therethrough and for substantially continuous reflection along the lengths of said fibers of a portion of said signal back through said fibers as backscattered light; and

    means for detecting the intensity of said backscattered light from each of said fibers as a function of time of reflection whereby each microbend along each fiber is indicated by an abrupt attenuation in said detected intensity and the time of detection is indicative of the location of the microbend along said fiber;

    said signal launching means and said detecting means being positioned at a common monitoring station, said signal launching means comprising a light source and said detecting means comprising a photodetector, and including optical means positioned generally adjacent one end of said fibers for direction of said pulsed optical signal into said fibers and for direction of said backscattered light to said photodetector.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×