Optically detected magnetic resonance imaging with an electromagnetic field resonator

Patent metadata

Field	Value
Publication number	US-10359480-B2
Application number	US-201515117796-A
Country	US
Kind code	B2
Filing date	Feb 13, 2015
Priority date	Feb 13, 2014
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

Measuring a sample includes providing a magnetic field at the sample using an electromagnetic field resonator. The electromagnetic field resonator includes two or more resonant structures at least partially contained within dielectric material of a substrate, at least a first resonant structure configured to provide the magnetic field at the sample positioned in proximity to the first resonant structure. The sample is characterized by an electron spin resonance frequency. A size of an inner area of the first resonant structure and a number of resonant structures included in the electromagnetic field resonator at least partially determine a range of an operating resonance frequency of the electromagnetic field resonator that includes the electron spin resonance frequency. Measuring the sample also includes receiving an output optical signal from the sample generated based at least in part on a magnetic field generated by the electromagnetic field resonator.

First claim

What is claimed is:

1. An apparatus comprising:
a substrate that includes a dielectric material;
an electromagnetic-field resonator that includes two or more resonant structures at least partially contained within the dielectric material, at least a first resonant-structure being configured to provide a magnetic field at a sample positioned in proximity to the first resonant structure, the sample being characterized by an electron-spin resonance-frequency, wherein a size of an inner area of the first resonant-structure and a number of resonant structures included in the electromagnetic-field resonator at least partially determine a range of an operating resonance-frequency of the electromagnetic-field resonator that includes the electron-spin resonance-frequency; and
an optical coupler positioned in proximity to the first resonant-structure and configured to receive an output optical-signal from the sample, the output optical-signal being generated based at least in part on a magnetic field generated by the electromagnetic-field resonator,
wherein the first resonant structure is configured to provide a magnetic field at the sample positioned in proximity to a first side of the electromagnetic-field resonator and
wherein the optical coupler is positioned in proximity to a second side of the electromagnetic-field resonator and is configured to receive the output optical-signal from the sample through an opening defined by the first resonant-structure.

2. The apparatus of claim 1 , further comprising a tuning element configured to tune the operating resonance-frequency of the electromagnetic-field resonator within the range.

3. The apparatus of claim 2 , wherein the first resonant-structure is configured to at least partially surround the sample within the inner area of the first resonant-structure.

4. The apparatus of claim 1 , wherein the range of the operating resonance-frequency includes at least some microwave frequencies.

5. The apparatus of claim 1 , wherein the size of the inner area provides a uniformity of the magnetic field generated by the electromagnetic-field resonator within about 10% or less over an area of the sample of about one square millimeter or more.

6. The apparatus of claim 1 , wherein the two or more resonant structures comprise two or more split rings.

7. The apparatus of claim 1 , wherein the substrate comprises a printed circuit board.

8. The apparatus of claim 1 , further comprising an optical coupler configured to receive an output optical-signal from the sample, the output optical-signal being generated based at least in part on a magnetic field generated by the electromagnetic-field resonator.

9. The apparatus of claim 8 , wherein the optical coupler is further configured to provide an input optical-signal to the sample.

10. The apparatus of claim 1 , further including a microwave coupler configured to couple a microwave signal into the electromagnetic-field resonator.

11. The apparatus of claim 10 , further including a microwave source configured to provide a pulsed microwave-signal to the microwave coupler, with a bandwidth of the pulsed microwave signal being within a bandwidth of the electromagnetic-field resonator.

12. The apparatus of claim 11 , further comprising a tuning element configured to tune the bandwidth of the electromagnetic-field resonator.

13. The apparatus of claim 12 , wherein the tuning element comprises a material that changes a quality factor of the electromagnetic-field resonator.

14. The apparatus of claim 1 , wherein the sample comprises diamond and wherein the electron-spin resonance-frequency is based on nitrogen-vacancy centers in the diamond.

15. The apparatus of claim 1 , wherein the sample comprises a thin-film material.

16. The apparatus of claim 1 , wherein the sample is positioned within a cryogenic chamber.

17. A method for measuring a sample, the method comprising:
providing a magnetic field at the sample using an electromagnetic-field resonator including two or more resonant structures at least partially contained within dielectric material of a substrate, at least a first resonant structure configured to provide the magnetic field at the sample positioned in proximity to the first resonant structure, the sample being characterized by an electron-spin resonance-frequency, wherein a size of an inner area of the first resonant structure and a number of resonant structures included in the electromagnetic-field resonator at least partially determine a range of an operating resonance frequency of the electromagnetic-field resonator that includes the electron-spin resonance frequency; and
receiving an output optical signal from the sample using an optical coupler positioned in proximity to the first resonant structure, the output optical signal being generated based at least in part on a magnetic field generated by the electromagnetic-field resonator,
wherein the first resonant-structure is configured to provide a magnetic field at the sample positioned in proximity to a first side of the electromagnetic-field resonator and
wherein the optical coupler is positioned in proximity to a second side of the electromagnetic-field resonator and is configured to receive the output optical-signal from the sample through an opening defined by the first resonant-structure.

18. The method of claim 17 , further comprising positioning the sample within a cryogenic chamber.

Assignees

• Harvard College
• Presidents And Fellows Of Harvard College

Inventors

• Bayat Khadijeh
• Loncar Marko

Classifications

• G01R33/62

  using double resonance (G01R33/24 takes precedence) · CPC title

• G01N1/00

  Sampling; Preparing specimens for investigation · CPC title

• G01N2201/00

  Features of devices classified in G01N21/00 · CPC title

• G01R33/323 Primary

  Detection of MR without the use of RF or microwaves, e.g. force-detected MR, thermally detected MR, MR detection via electrical conductivity, optically detected MR · CPC title

• G02B1/00

  Optical elements characterised by the material of which they are made; Optical coatings for optical elements · CPC title