METHOD FOR RESOLVING NATURAL SENSOR AMBIGUITY FOR DNV DIRECTION FINDING APPLICATIONS

• US 20170212183A1
• Filed: 01/21/2016
• Published: 07/27/2017
• Est. Priority Date: 01/21/2016
• Status: Abandoned Application

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Egan, Laird Nicholas, Stockman, Emanuel Solomon
• Application Number:
  US15/003,678
• Publication Number:
  US 20170212183A1
• Time in Patent Office: Days
• CPC Class Codes: G01R 33/032 using magneto-optic devices, e.g. Faraday or Cotton-Mouton effect

Abstract

A system for unambiguously determines a signed magnetic field vector from a magneto-optical defect center magnetic field sensor. The magneto-optical magnetic field sensor may include a diamond nitrogen vacancy material.

Claims

1. A system comprising:

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

a magnetic field source;

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;

determine a first equilibration time for a first peak of a Lorentzian pair based on a received light detection signal from the optical detector,

determine a second equilibration time for a second peak of the Lorentzian pair based on a received light detection signal from the optical detector, and

determine a sign of the magnetic field vector at the NV diamond material based on the first equilibration time and the second equilibration time.

2. The system of claim 1, wherein the controller is configured to assign a positive spin state to the peak of the Lorentzian pair with the longer equilibration time.

3. The system of claim 1, wherein the first equilibration time and the second equilibration time are determined by measuring the time to reach 60% of a normalized equilibrium intensity after the beginning of an RF pulse, wherein the normalized equilibrium intensity is determined based on the intensity in the absence of the RF pulse and the equilibrium intensity in the presence of the RF pulse.

4. A system, comprising:

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

a magnetic field source;

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;

control the RF excitation source to provide pulsed RF excitation to the NV diamond material, and

determine a sign of the magnetic field vector at the NV diamond material based on a received light detection signal from the optical detector.

5. The system of claim 4, wherein the controller is configured to control the optical excitation source to provide continuous wave optical excitation to the NV diamond.

6. The system of claim 4, wherein the controller is further configured to identify Lorentzian peaks in a received light detection signal from the optical detector as a function of RF excitation frequency.

7. The system of claim 6, wherein the controller is configured to determine a sign of the magnetic field vector based on an equilibration time for a pair of the identified Lorentzian peaks.

8. A system, comprising:

a magneto-optical defect center material;

a magnetic field source;

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;

control the RF excitation source to provide pulsed RF excitation to the magneto-optical defect center material,

control the optical excitation source to provide optical excitation to the magneto-optical defect center material, and

determine a sign of the magnetic field vector at the magneto-optical defect center material based on a received light detection signal from the optical detector.

9. The system of claim 8, wherein the controller is configured to control the optical excitation source to provide continuous wave optical excitation to the magneto-optical defect center material.

10. The system of claim 8, wherein the controller is further configured to identify Lorentzian peaks in a received light detection signal from the optical detector as a function of RF excitation frequency.

11. The system of claim 10, wherein the controller is configured to determine a sign of the magnetic field vector based on an equilibration time for a pair of the identified Lorentzian peaks.