# US 10,120,039 B2 · Apparatus and method for closed loop processing for a magnetic detection system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,120,039 B2 - Document ID: US10120039B2 - Status: Granted - Kind: B2 - Application number: 15/003,519 - Filed: 2016-01-21 - Published: 2017-05-25 - Granted: 2018-11-06 - Earliest claimed: 2015-11-20 - Assignees: Lockheed Martin Corporation - Applicants: Lockheed Martin Corporation - Inventors: John B. Stetson, Jr.; Jeff D. Cammerata - Web page: https://patentgrep.com/patent/US10120039B2 ## CPC - G01R 33/032: using magneto-optic devices, e.g. Faraday {or Cotton-Mouton effect} - G01R 33/0017: {Means for compensating offset magnetic fields or the magnetic flux to be measured; Means for generating calibration magnetic fields} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## 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 ### Claim 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. ### Claim 2 (depends on 1) The system for magnetic detection of claim 1, wherein the compensatory magnetic field is the inverse of the external magnetic field. ### Claim 3 (depends on 1) 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. ### Claim 4 (depends on 3) 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. ### Claim 5 (depends on 1) The system for magnetic detection of claim 1, wherein the optical signal is based on hyperfine states of the NV diamond material. ### Claim 6 (depends on 5) 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. ### Claim 7 (depends on 6) 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. ### Claim 8 A system for magnetic detection, comprising: a magneto-optical defect center material comprising a plurality of magneto-optical defect centers; means for generating a compensatory magnetic field applied to the magneto-optical defect center material; means for providing radio frequency (RF) excitation to the magneto-optical defect center material; means for detecting an optical signal emitted by the magneto-optical defect center material; means for receiving the optical signal emitted by the magneto-optical defect center material; and means for computing 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, wherein the compensatory magnetic field is generated to offset a shift in the optical signal emitted by the magneto-optical defect center material caused by an external magnetic field. ### Claim 9 (depends on 8) The system of claim 8, wherein the optical signal is based on hyperfine states of the magneto-optical defect center material. ### Claim 10 (depends on 9) 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 magneto-optical defect center material. ### Claim 11 (depends on 9) 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 magneto-optical defect center material for a plurality of magneto-optical defect center orientations. ### Claim 12 A system for magnetic detection, comprising: a magneto-optical defect center material comprising a plurality of magneto-optical defect centers; a first magnetic field generator configured to generate a bias magnetic field that is applied to the magneto-optical defect center material; a second magnetic field generator configured to generate a compensatory 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; detect a shift in the optical signal emitted by the magneto-optical defect center 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 magneto-optical defect center material caused by the external magnetic field. ### Claim 13 (depends on 12) The system for magnetic detection of claim 12, wherein the compensatory magnetic field is the inverse of the external magnetic field. ### Claim 14 (depends on 12) 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. ### Claim 15 (depends on 14) 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. ### Claim 16 (depends on 12) The system for magnetic detection of claim 12, wherein the first magnetic field generator is a permanent magnet. ### Claim 17 (depends on 12) The system for magnetic detection of claim 12, wherein the optical signal is based on hyperfine states of the magneto-optical defect center material. ### Claim 18 (depends on 17) 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 magneto-optical defect center material. ### Claim 19 A method for magnetic detection using a magneto-optical defect center material comprising a plurality of magneto-optical defect centers, comprising: providing radio frequency (RF) excitation to the magneto-optical defect center material; providing optical excitation to the magneto-optical defect center material; receiving an optical signal emitted by the magneto-optical defect center material; computing 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; detecting a shift in the optical signal emitted by the magneto-optical defect center 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 magneto-optical defect center material caused by the external magnetic field. ### Claim 20 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; 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, wherein the optical signal is based on hyperfine states of 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 a point of the largest gradient of the hyperfine states of the magneto-optical defect center material; detect a shift of the optical signal emitted by the magneto-optical defect center 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 magneto-optical defect center material caused by the external magnetic field. ### Claim 21 (depends on 20) 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 magneto-optical defect center material for a plurality of magneto-optical defect center orientations. ### Claim 22 A method for magnetic detection using magneto-optical defect center material comprising a plurality of magneto-optical defect centers, comprising: providing radio frequency (RF) excitation to the magneto-optical defect center material; providing optical excitation to the magneto-optical defect center material; receiving an optical signal emitted by the magneto-optical defect center material; computing 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 generating 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. ### Claim 23 (depends on 22) The method of claim 22, wherein the optical signal is based on hyperfine states of the magneto-optical defect center material and wherein the method further comprises detecting a gradient of the optical signal based on the hyperfine states of the magneto-optical defect center material. ### Claim 24 (depends on 22) The method of claim 22, wherein a point of the largest gradient of the optical signal is detected. ### Claim 25 A system for magnetic detection, comprising: a magneto-optical defect center material comprising a plurality of magneto-optical defect centers; 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, wherein the optical signal is based on hyperfine states of the magneto-optical defect center 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 magneto-optical defect center material for a plurality of magneto-optical defect center 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 magneto-optical defect center material based on a point of the largest gradient of the optical signal based on the hyperfine states of the magneto-optical defect center material for the plurality of magneto-optical defect center orientations; detect a shift of the optical signal emitted by the magneto-optical defect center 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 magneto-optical defect center material caused by the external magnetic field. ### Claim 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. ### Claim 27 (depends on 26) The system for magnetic detection of claim 26, wherein the compensatory magnetic field is the inverse of the external magnetic field. ### Claim 28 (depends on 26) The system for magnetic detection of claim 26, wherein the magnetic field generator comprises a plurality of coils configured to generate a magnetic field having a plurality of predetermined directions. ### Claim 29 (depends on 28) The system for magnetic detection of claim 28, 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. ### Claim 30 (depends on 26) The system for magnetic detection of claim 26, wherein the optical signal is based on hyperfine states of the magneto-optical defect center material. ### Claim 31 (depends on 30) The system for magnetic detection of claim 30, wherein the controller is configured to detect a gradient of the optical signal based on the hyperfine states of the magneto-optical defect center material. ### Claim 32 (depends on 31) The system for magnetic detection of claim 31, wherein the controller is configured to detect a point of the largest gradient of the optical signal. ### Claim 33 (depends on 8) The system for magnetic detection of claim 8, wherein the magneto-optical defect center material is a nitrogen vacancy diamond material. ### Claim 34 (depends on 12) The system for magnetic detection of claim 12, wherein the magneto-optical defect center material is a nitrogen vacancy diamond material. ### Claim 35 (depends on 19) The method for magnetic detection of claim 19, wherein the magneto-optical defect center material is a nitrogen vacancy diamond material. ### Claim 36 (depends on 20) The system for magnetic detection of claim 20, wherein the magneto-optical defect center material is a nitrogen vacancy diamond material. ### Claim 37 (depends on 22) The method for magnetic detection of claim 22, wherein the magneto-optical defect center material is a nitrogen vacancy diamond material. ### Claim 38 (depends on 25) The system for magnetic detection of claim 25, wherein the magneto-optical defect center material is a nitrogen vacancy diamond material.