High speed sequential cancellation for pulsed mode

• US 10,274,550 B2
• Filed: 03/24/2017
• Issued: 04/30/2019
• Est. Priority Date: 03/24/2017
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Bruce, Gregory Scott, Kaup, Peter G., Manickam, Arul
• Primary Examiner(s): Fuller, Rodney E
• Application Number:
  US15/468,397
• Publication Number:
  US 20180275223A1
• Time in Patent Office: 767 Days
• Field of Search: 324301
• CPC Class Codes: G01N 24/10 by using electron paramagnetic resonance G01N24/12 takes precedence
• CPC Class Codes: G01R 33/032 using magneto-optic devices, e.g. Faraday or Cotton-Mouton effect
• CPC Class Codes: G01R 33/26 using optical pumping
• CPC Class Codes: G01R 33/60 using electron paramagnetic resonance G01R33/24, G01R33/62 take precedence

Abstract

Magnetometers with high bandwidth acquisition of data with increased sensitivity are described herein. Increased bandwidth and sensitivity may be achieved by eliminating a reference signal for full repolarization of the magneto-optical defect center material prior to acquisition. Elimination of the reference signal eliminates the time needed to repolarize the magneto-optical defect center material and the acquisition time for the reference signal. A radiofrequency (RF) pulse sequence may be activate to apply an RF field to the magneto-optical defect center material and a magnetic field measurement may be acquired using the magneto-optical defect center material. The magnetic field measurement may be acquired independent of a reference magnetic field measurement.

Claims

1. A system comprising:

a magnetometer including;

a magneto-optical defect center material,

an optical excitation source,

a radiofrequency (RF) excitation source, and

an optical sensor; and

a controller, the controller configured to;

repetitively activate a radiofrequency (RF) pulse sequence for the RF excitation source to apply a RF field to the magneto-optical defect center material,

repetitively activate an optical pulse sequence for the optical excitation source to apply a laser pulse to the magneto-optical defect center material, and

repetitively acquire in conjunction with the optical pulse sequence a repetitive magnetic field measurement from the magneto-optical defect center material using the optical sensor, wherein the magnetic field measurement and the optical pulse sequence are performed repetitively in a continuous cycle independent of a reference magnetic field measurement.

2. The system of claim 1, wherein acquiring the repetitive magnetic field measurement comprises a polarization pulse length.

3. The system of claim 1, wherein the controller processes the repetitive magnetic field measurement directly to obtain magnetometry measurements.

4. The system of claim 1, wherein the controller is further configured to determine a vector of the repetitive magnetic field measurement.

5. The system of claim 1, wherein the controller uses a fixed system rail photo measurement as a nominal reference value.

6. The system of claim 1, wherein the magneto-optical defect center material is a diamond having nitrogen vacancies.

7. The system of claim 1, wherein the controller is further configured to process the magnetic field measurement.

8. A method for operating a magnetometer having a magneto-optical defect center material, the method comprising:

activating a radiofrequency (RF) pulse sequence to apply an RF field to the magneto-optical defect center material;

acquiring a nominal ground reference signal for the magneto-optical defect center material; and

acquiring a magnetic field measurement using the magneto-optical defect center material, wherein the magnetic field measurement is acquired independent of a reference magnetic field measurement.

9. The method of claim 8, wherein acquiring the magnetic field measurement comprises a polarization pulse length.

10. The method of claim 8, wherein acquiring a magnetic field measurement comprises processing the magnetic field measurement directly to obtain magnetometry measurements.

11. The method of claim 8 further comprising determining a vector of the repetitive magnetic field measurement.

12. The method of claim 8, wherein acquiring a magnetic field measurement comprises using a fixed system rail photo measurement as a nominal reference value.

13. The method of claim 8, wherein the magneto-optical defect center material is a diamond having nitrogen vacancies.

14. The method of claim 8 further comprising processing, using a controller, the magnetic field measurement.

15. A sensor comprising:

a magneto-optical defect center material;

a radiofrequency (RF) excitation source; and

a controller configured to;

activate a radiofrequency (RF) pulse sequence for the RF excitation source to apply a RF field to the magneto-optical defect center material,

acquire a nominal ground reference signal for the magneto-optical defect center material, and

acquire a magnetic field measurement from the magneto-optical defect center material, wherein the magnetic field measurement is acquired independent of a reference magnetic field measurement.

16. The sensor of claim 15, wherein acquiring the magnetic field measurement comprises a polarization pulse length.

17. The sensor of claim 15, wherein the controller processes the magnetic field measurement directly to obtain magnetometry measurements.

18. The sensor of claim 15, wherein the controller is further configured to determine a vector of the magnetic field measurement.

19. The sensor of claim 15, wherein the controller uses a fixed system rail photo measurement as a nominal reference value.

20. The sensor of claim 15, wherein the magneto-optical defect center material is a diamond having nitrogen vacancies.