Accession Number : ADD011830

Title :   Fiber Optic System for Measuring Electric Fields.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Bobb,L C

Report Date : 18 Jun 1985

Pagination or Media Count : 5

Abstract : A fiber optic sensor system and associated technique is disclosed for measuring an electric field wherein a sensor arm of optical fiber cable is wound about a core member of piezoelectric material. A reference arm of optical fiber cable substantially equal in optical path length to the sensor arm is isolated and connected in parallel to the sensor arm so that coherent light generated by a single model laser source may be split through the fiber-optic arms and recombined after passage there-through for phase comparison. When subjected to a local electric field, the core member of piezoelectric material varies in dimensions and thereby causes a change in the stain in the optical fiber cable of the sensor arm. Relative phase changes in the coherent light caused by the resulting optical path length change of the strained homodyne demodulator and deterministive of the value of the local electric field. A vane-type shield is adapted to be rotated about the core member for periodically reducing the local electric field to near zero thereby providing a reference level for field measurement.

Descriptors :   *PATENTS, *INSTRUMENTATION, *OPTICAL INTERFEROMETERS, *MEASUREMENT, *ELECTRIC FIELDS, *FIBER OPTICS, DEMODULATORS, LASER BEAMS, TRANSDUCERS, COHERENT OPTICAL RADIATION, PIEZOELECTRIC MATERIALS, LIGHT SOURCES, OPTICAL WAVEGUIDES, CABLES, SOURCES, LENGTH, MODELS, OPTICS, LASERS, OPTICAL EQUIPMENT, INVENTIONS, PATHS

Subject Categories : Lasers and Masers
      Test Facilities, Equipment and Methods
      Electricity and Magnetism
      Fiber Optics and Integrated Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE