Fiber optic sensor system
AssigneeHalliburton Energy Services, Inc.
InventorJohn Berthold
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Abstract
A method and apparatus for detecting seismic vibrations using a series of MEMS units, with each MEMS unit including an interferometer is described. The interferometers on the MEMS units receive and modulate light from two differing wavelengths by way of a multiplexing scheme involving the use of Bragg gratings and light circulators, and an optoelectronic processor receives and processes the modulated light to discern vibrational movement of the system, which in turn allows for monitoring and calculation of a specified environmental parameter, such as seismic activity, temperature or pressure.
Claims18
A multiplexed fiber optic sensor system comprising:
- a source of broadband light;
- a plurality of interferometers which modulate light received from the source;
- a plurality of circulators associated with each interferometer, each of said circulators including at least one Bragg grating;
- an optoelectronic processor which receives modulated light and produces a signal indicative of an environmental parameter, said optoelectronic processor having a cross-correlator;
- and
- means for delivering light between the light source, the interferometers, the circulators and the optoelectronic processor.
A fiber optic sensor system comprising:
- a source of light;
- at least one MEMS device which modulates light received from the source, said MEMS device having an interferometer and a cantilever;
- an optoelectronic processor which receives the modulated light and produces a signal indicative of an environmental parameter;
- and
- means for delivering the light between the light source, the MEMS device and the optoelectronic processor.
A method of monitoring an environmental parameter comprising:
- circulating a broadband light source to a plurality of interferometers so that each of said interferometers receives a unique wavelength band from the broadband light source, each of said interferometers modulating the light provided thereto;
- providing the modulated light from each of said interferometers to an optoelectronic processor;
- and
- cross-correlating the modulated light to produce a signal indicative of an environmental parameter.
Dependencies are inferred from the claim text.