Optical network configuration with intrinsic delay for swept-wavelength interferometry systems
AssigneeBaker Hughes Incorporated
InventorsRoger Glen Duncan, Brooks A. Childers
Life of this patent
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Abstract
A method, apparatus and optical network for obtaining a signal from a sensor in a fiber optic cable at a downhole location is disclosed. A reference signal is propagated through the fiber optic cable. A beam of light is received from the fiber optic cable, wherein the beam of light includes the propagated reference signal and the signal from the sensor generated from an interaction of the sensor and the reference signal. The propagated reference signal is obtained from the received beam of light. The signal from the sensors is obtained by sampling the received beam of light using the obtained propagated reference signal.
Claims17
A method of obtaining a signal from a sensor in a fiber optic cable at a downhole location, comprising:
- propagating a reference signal through the fiber optic cable;
- receiving from the fiber optic cable a beam of light that includes the propagated reference signal and the signal generated from an interaction of the sensor and the reference signal;
- obtaining the propagated reference signal from the received beam of light from the fiber optic cable;
- generating a trigger signal from the reference signal obtained from the fiber optic cable;
- and
- obtaining the signal from the sensor by sampling the received beam of light using the generated trigger signal.
An apparatus for obtaining a signal from a sensor in a fiber optic cable, comprising:
- a light source configured to propagate a reference signal through the fiber optic cable;
- a trigger circuit configured to:
- receive a beam of light from the fiber optic cable that includes the reference signal after it has propagated through the fiber optic cable and a signal from the sensor responsive to the reference signal,
- obtain the reference signal after it has propagated through the fiber optic cable from the received beam of light, and
- generate a trigger signal from the obtained reference signal;
- and a sampling circuit configured to obtain the signal from the sensor from the received beam of light by sampling the received beam of light using the generated trigger signal.
An optical network, comprising:
- a fiber optic cable including a sensor configured to provide signals relating to a parameter of interest;
- a light source configured to propagate a reference signal through the fiber optic cable at a plurality of wavelengths;
- a splitter configured to split a light beam received from the fiber optic cable into a first light beam and a second light beam, each such light beam including the reference signal having an intrinsic delay after it has propagated through the fiber optic cable and a sensor signal obtained from the sensor in response to the reference signal propagated by the light source interacting with the sensor;
- a trigger circuit configured to generate a trigger signal corresponding to the reference signal having the intrinsic delay, the trigger signal corresponding to a wavelength in the plurality of wavelengths;
- and
- a sampling circuit configured to sample the first light beam in response to receiving the trigger signal generated at the trigger circuit.
Dependencies are inferred from the claim text.