APPARATUS AND METHOD FOR CLOSED LOOP PROCESSING FOR A MAGNETIC DETECTION SYSTEM

• US 20170146616A1
• Filed: 01/21/2016
• Published: 05/25/2017
• Est. Priority Date: 11/20/2015
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: STETSON, JR., John B., CAMMERATA, Jeff D.
• Granted Patent: US 10,120,039 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 33/0017 Means for compensating offset magnetic fields or the magnetic flux to be measured; Means for generating calibration magnetic fields
• CPC Class Codes: G01R 33/032 using magneto-optic devices, e.g. Faraday or Cotton-Mouton effect

Abstract

A system for magnetic detection includes a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers, a magnetic field generator that generates a magnetic field that is applied to the NV diamond material, a radio frequency (RF) excitation source that provides RF excitation to the NV diamond material, an optical excitation source that provides optical excitation to the NV diamond material, an optical detector that receives an optical signal emitted by the NV diamond material, and a controller. The controller is configured to compute a total incident magnetic field at the NV diamond material based on the optical signal emitted by the NV diamond material, and drive the magnetic field generator to generate a compensatory magnetic field, the generated compensatory magnetic field being set to offset a shift in the optical signal emitted by the NV diamond material caused by an external magnetic field.

Claims

1. A system for magnetic detection, comprising:

a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers;

a magnetic field generator configured to generate a magnetic field that is applied to the NV diamond material;

a radio frequency (RF) excitation source configured to provide RF excitation to the NV diamond material;

an optical excitation source configured to provide optical excitation to the NV diamond material;

an optical detector configured to receive an optical signal emitted by the NV diamond material; and

a controller configured to;

compute a total incident magnetic field at the NV diamond material based on the optical signal emitted by the NV diamond material; and

drive the magnetic field generator to generate a compensatory magnetic field, the generated compensatory magnetic field being set to offset a shift in the optical signal emitted by the NV diamond material caused by an external magnetic field.

2. The system for magnetic detection of claim 1, wherein the compensatory magnetic field is the inverse of the external magnetic field.

3. The system for magnetic detection of claim 1, wherein the magnetic field generator comprises a plurality of coils configured to generate a magnetic field having a plurality of predetermined directions.

4. The system for magnetic detection of claim 3, wherein the plurality of coils is configured to generate a magnetic field having three predetermined directions, wherein each of the predetermined directions are orthogonal to one another.

5. The system for magnetic detection of claim 1, wherein the optical signal is based on hyperfine states of the NV diamond material.

6. The system for magnetic detection of claim 5, wherein the controller is configured to detect a gradient of the optical signal based on the hyperfine states of the NV diamond material.

7. The system for magnetic detection of claim 6, wherein the controller is configured to detect a point of the largest gradient of the optical signal.

8. A system for magnetic detection, comprising:

a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers;

means for generating a compensatory magnetic field applied to the NV diamond material;

means for providing radio frequency (RF) excitation to the NV diamond material;

means for detecting an optical signal emitted by the NV diamond material;

means for receiving the optical signal emitted by the NV diamond material; and

means for computing a total incident magnetic field at the NV diamond material based on the optical signal emitted by the NV diamond material,

wherein the compensatory magnetic field is generated to offset a shift in the optical signal emitted by the NV diamond material caused by an external magnetic field.

9. The system of claim 8, wherein the optical signal is based on hyperfine states of the NV diamond material.

10. The system of claim 9, further comprising means for detecting a point of the largest gradient of the optical signal based on the hyperfine states of the NV diamond material.

11. The system of claim 9, further comprising means for generating a bias magnetic field, and means for detecting a plurality of points of the largest gradients of the optical signal based on the hyperfine states of the NV diamond material for a plurality of NV diamond orientations.

12. A system for magnetic detection, comprising:

a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers;

a first magnetic field generator configured to generate a bias magnetic field that is applied to the NV diamond material;

a second magnetic field generator configured to generate a compensatory magnetic field that is applied to the NV diamond material;

a radio frequency (RF) excitation source configured to provide RF excitation to the NV diamond material;

an optical excitation source configured to provide optical excitation to the NV diamond material;

an optical detector configured to receive an optical signal emitted by the NV diamond material; and

a controller configured to;

compute a total incident magnetic field at the NV diamond material based on the optical signal emitted by the NV diamond material;

detect a shift in the optical signal emitted by the NV diamond material due to an external magnetic field; and

drive the second magnetic field generator to generate the compensatory magnetic field to offset the shift in the optical signal emitted by the NV diamond material caused by the external magnetic field.

13. The system for magnetic detection of claim 12, wherein the compensatory magnetic field is the inverse of the external magnetic field.

14. The system for magnetic detection of claim 12, wherein the second magnetic field generator comprises a plurality of coils configured to generate a magnetic field having a plurality of predetermined directions.

15. The system for magnetic detection of claim 14, wherein the plurality of coils is configured to generate a magnetic field having three predetermined directions, wherein each of the predetermined directions are orthogonal to one another.

16. The system for magnetic detection of claim 12, wherein the first magnetic field generator is a permanent magnet.

17. The system for magnetic detection of claim 12, wherein the optical signal is based on hyperfine states of the NV diamond material.

18. The system for magnetic detection of claim 17, wherein the controller is configured to detect a point of the largest gradient of the optical signal based on the hyperfine states of the NV diamond material.

19. A method for magnetic detection using a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers, comprising:

providing radio frequency (RF) excitation to the NV diamond material;

providing optical excitation to the NV diamond material;

receiving an optical signal emitted by the NV diamond material;

computing a total incident magnetic field at the NV diamond material based on the optical signal emitted by the NV diamond material;

detecting a shift in the optical signal emitted by the NV diamond material due to an external magnetic field; and

generating a compensatory magnetic field, the generated compensatory magnetic field being set to offset the shift in the optical signal emitted by the NV diamond material caused by the external magnetic field.

20. A system for magnetic detection, comprising:

a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers;

a magnetic field generator configured to generate a magnetic field;

a radio frequency (RF) excitation source configured to provide RF excitation to the NV diamond material;

an optical excitation source configured to provide optical excitation to the NV diamond material;

an optical detector configured to receive an optical signal emitted by the NV diamond material, wherein the optical signal is based on hyperfine states of the NV diamond material; and

a controller configured to;

compute a total incident magnetic field at the NV diamond material based on a point of the largest gradient of the hyperfine states of the NV diamond material;

detect a shift of the optical signal emitted by the NV diamond material due to an external magnetic field; and

drive the magnetic field generator to generate a compensatory magnetic field, the generated compensatory magnetic field being set to offset the shift in the optical signal emitted by the NV diamond material caused by the external magnetic field.

21. The system for magnetic detection of claim 20, wherein the controller is further configured to drive the magnetic field generator to generate a bias magnetic field, the bias magnetic field being configured to separate the optical signal based on the hyperfine states of the NV diamond material for a plurality of NV diamond orientations.

22. A method for magnetic detection using a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers, comprising:

providing radio frequency (RF) excitation to the NV diamond material;

providing optical excitation to the NV diamond material;

receiving an optical signal emitted by the NV diamond material;

computing a total incident magnetic field at the NV diamond material based on the optical signal emitted by the NV diamond material; and

generating a compensatory magnetic field, the generated compensatory magnetic field being set to offset a shift in the optical signal emitted by the NV diamond material caused by an external magnetic field.

23. The method of claim 22, wherein the optical signal is based on hyperfine states of the NV diamond material and wherein the method further comprises detecting a gradient of the optical signal based on the hyperfine states of the NV diamond material.

24. The method of claim 22, wherein a point of the largest gradient of the optical signal is detected.

25. A system for magnetic detection, comprising:

a nitrogen vacancy (NV) diamond material comprising a plurality of NV centers;

a radio frequency (RF) excitation source configured to provide RF excitation to the NV diamond material;

an optical excitation source configured to provide optical excitation to the NV diamond material;

an optical detector configured to receive an optical signal emitted by the NV diamond material, wherein the optical signal is based on hyperfine states of the NV diamond material;

a first magnetic field generator configured to generate a bias magnetic field, the bias magnetic field being configured to separate the optical signal based on the hyperfine states of the NV diamond material for a plurality of NV diamond orientations;

a second magnetic field generator configured to generate a compensatory magnetic field; and

a controller configured to;

compute a total incident magnetic field at the NV diamond material based on a point of the largest gradient of the optical signal based on the hyperfine states of the NV diamond material for the plurality of NV diamond orientations;

detect a shift of the optical signal emitted by the NV diamond material due to an external magnetic field; and

drive the magnetic field generator to generate a compensatory magnetic field, the generated compensatory magnetic field being set to offset the shift in the optical signal emitted by the NV diamond material caused by the external magnetic field.

26. A system for magnetic detection, comprising:

a magneto-optical defect center material comprising a plurality of magneto-optical defect centers;

a magnetic field generator configured to generate a magnetic field that is applied to the magneto-optical defect center material;

a radio frequency (RF) excitation source configured to provide RF excitation to the magneto-optical defect center material;

an optical excitation source configured to provide optical excitation to the magneto-optical defect center material;

an optical detector configured to receive an optical signal emitted by the magneto-optical defect center material; and

a controller configured to;

compute a total incident magnetic field at the magneto-optical defect center material based on the optical signal emitted by the magneto-optical defect center material; and

drive the magnetic field generator to generate a compensatory magnetic field, the generated compensatory magnetic field being set to offset a shift in the optical signal emitted by the magneto-optical defect center material caused by an external magnetic field.