SYSTEMS AND METHODS FOR DETERMINISTIC EMITTER SWITCH MICROSCOPY

• US 20160161429A1
• Filed: 03/27/2014
• Published: 06/09/2016
• Est. Priority Date: 10/19/2011
• Status: Active Grant

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Englund, Dirk R., Chen, Edward H., Gaathon, Ophir
• Granted Patent: US 9,632,045 B2
• Time in Patent Office: Days
• CPC Class Codes: G01N 21/6402 Atomic fluorescence; Laser induced fluorescence
• CPC Class Codes: G01N 21/6458 Fluorescence microscopy fluorescence microscopes per se G02B21/0076 and G02B21/16
• CPC Class Codes: G01N 24/006 using optical pumping magnetometers using optical pumping G01R33/26, optical pumping of lasers H01S3/091
• CPC Class Codes: G01N 24/10 by using electron paramagnetic resonance G01N24/12 takes precedence
• CPC Class Codes: G01R 33/323 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

Abstract

Techniques for deterministic switch microscopy include resolving at least one nitrogen vacancy center in a diamond structure. A magnetic field can be applied across the diamond structure and the nitrogen vacancy centers can be optically excited. The nitrogen vacancy centers can be switched from a dark state to a bright state or a bright state by a dark state by applying at least one microwave pulse. A fluorescent response of each nitrogen vacancy center can be detected and a nitrogen vacancy center can be resolved based on the fluorescent response of each nitrogen vacancy center as it corresponds to the orientation of the nitrogen vacancy center relative to the applied magnetic field.

Claims

1. A method for resolving at least one nitrogen vacancy center, comprising:

providing at least one diamond structure with one or more nitrogen vacancy centers within a focal location, each being in either a dark state or a bright state;

applying a magnetic field across the at least one diamond structure;

optically exciting the one or more nitrogen vacancy centers;

switching at least one nitrogen vacancy center from the dark state to the bright state or from the bright state to the dark state by applying at least one microwave pulse to the one or more nitrogen vacancy centers;

detecting a fluorescent response of each nitrogen vacancy center; and

resolving at least one of the nitrogen vacancy centers based on the fluorescent response of each nitrogen vacancy center, the fluorescent response of each nitrogen vacancy center corresponding to its orientation relative to the magnetic field.

2. The method of claim 1, wherein the optically exciting includes directing a continuous wave of pump light at approximately 532 nm to the nitrogen vacancy center.

3. The method of claim 1, wherein the optically exciting includes applying a pulse of pump light at approximately 532 nm to the nitrogen vacancy center prior to applying the at least one microwave pulse, and applying a pulse of pump light at approximately 532 nm to the nitrogen vacancy center subsequent to applying the at least one microwave pulse.

4. The method of claim 1, wherein the providing at least one diamond structure with one or more nitrogen vacancy centers further comprises providing a plurality of nitrogen vacancy centers, at least some having differing orientations with respect to the magnetic field, whereby a spin sublevel of each nitrogen vacancy center experiences a Zeeman splitting corresponding to the orientation of the nitrogen vacancy center with respect to the magnetic field.

5. The method of claim 4, wherein applying at least one microwave pulse further comprises tuning a first microwave pulse to a field splitting frequency of a first one of the nitrogen vacancy centers, thereby modulating the fluorescent response of the first one of the nitrogen vacancy centers.

6. The method of claim 5, wherein applying at least one microwave pulse further comprises tuning at least a second microwave pulse to a field splitting frequency of a second one of the nitrogen vacancy centers, thereby modulating the fluorescent response of the second one of the nitrogen vacancy centers.

7. The method of claim 6, wherein applying at least one microwave pulse further comprises:

applying the first microwave pulse at a first frequency, the first frequency tuned to the field splitting frequency of the first one of the nitrogen vacancy centers;

applying the second microwave pulse at a second frequency, the second frequency tuned to the field splitting frequency of the second one of the nitrogen vacancy centers; and

applying at least a third microwave pulse at a third frequency, the third frequency tuned a frequency not corresponding to a field splitting frequency of either the first or the second one of the nitrogen vacancy centers.

8. The method of claim 6, wherein detecting the fluorescent response of each nitrogen vacancy center further comprises:

generating a first intensity plot of a first fluorescent response corresponding to the first frequency;

generating a second intensity plot of a second fluorescent response corresponding to the second frequency; and

generating at least a third intensity plot of a third fluorescent response corresponding to the third frequency.

9. The method of claim 8, wherein resolving the at least one nitrogen vacancy center includes determining the position of the first one of the nitrogen vacancy centers by subtracting the first and third intensity plots from the second intensity plot.

10. The method of claim 1, wherein applying at least one microwave pulse further includes continuously varying a frequency of a microwave emission.

11. The method of claim 1, wherein the switching at least one nitrogen vacancy center and the detecting a florescent response further comprises applying a plurality of microwave pulses and detecting a plurality of fluorescent responses, corresponding to the plurality of microwave pulses, to obtain a full electron spin resonance spectrum for a plurality of locations of a sample;

and wherein resolving at least one nitrogen vacancy center further comprises;

fitting the electronic spin resonance spectrum with a sum of Lorentzian dips;

generating an intensity map for the nitrogen vacancy center using contrasts from the fitted electron spin resonance spectrum.

12. The method of claim 11, wherein at least one of the Lorentzian dips at least partially overlaps at least one other of the Lorentzian dips.

13. The method of claim 1, wherein the focal location is a diffraction-limited area.

14. The method of claim 1, wherein the focal location is a wide field of view.

15. The method of claim 1, wherein the focal location is at least one diffraction-limited area selected from a wide field of view, the selected at least one diffraction-limited area having a fluorescent response with an intensity above a threshold.

16. The method of claim 1, wherein the focal location is a confocal scan area.

17. The method of claim 1, further comprising:

providing at least one fluorophore having an emission spectrum at least partially overlapping with an emission spectrum of the one or more nitrogen vacancy centers, wherein a fluorescent response of one of the nitrogen vacancy centers optically excites the fluorophore if the one of the nitrogen vacancy centers is within a threshold distance of fluorophore; and

detecting a fluorescent response of the fluorophore corresponding to the optical excitation of the one of the nitrogen vacancy centers.

18. The method of claim 17, further comprising determining a distance of one of the nitrogen vacancy centers from the fluorophore based on at least the fluorescent response of the one of the nitrogen vacancy centers and the fluorescent response of the fluorophore.

19. The method of claim 17, further comprising determining an orientation of a magnetic dipole of a molecule, the fluorophore coupled to the molecule, based on at least the fluorescent response of the one of the nitrogen vacancy centers and the fluorescent response of the fluorophore.

20. The method of claim 1, wherein the at least one diamond structure is exposed to an environment, wherein applying at least one microwave pulse includes applying two or more microwave pulses, each microwave pulse having a different frequency, and wherein detecting the fluorescent response of each nitrogen vacancy center includes detecting a fluorescent response corresponding to each microwave pulse, the method further comprising determining, based on the fluorescent response of each nitrogen vacancy center, a characteristic of the environment.

21. The method of claim 20, wherein the characteristic of the environment includes local magnetic field, local electric field, or pH.

22. The method of claim 1, further comprising determining the location of a particle corresponding to the resolved at least one of the nitrogen vacancy centers.

29. The method of claim 1, wherein the focal location includes a confocal scan area, and wherein the array of pixels corresponds to at least the confocal scan area.

23. A system for resolving at least one nitrogen vacancy center within a focal location using an applied magnetic field, comprising:

a light source, operatively configured to excite the at least one nitrogen vacancy center in the presence of the applied magnetic field, thereby inducing the at least one nitrogen vacancy center to produce a fluorescent response;

a photodetector arranged to detect the fluorescent response, if any;

a tunable microwave emitter arranged to apply at least one microwave pulse to the at least one nitrogen vacancy center; and

a control unit, coupled to the photodetector and the tunable microwave emitter, configured to adjust the frequency of the tunable microwave emitter, and configured to resolve the at least one nitrogen vacancy center based on the fluorescent response, the fluorescent response corresponding to its orientation relative to the magnetic field.

24. The system of claim 23, wherein the photodetector includes an array of pixels, and wherein the photodetector is further arranged to detect an intensity map of the fluorescent response across the array of pixels.

25. The system of claim 24, further comprising far-field optics to direct the fluorescent response to the photodetector.

26. The system of claim 25, wherein the focal location includes a diffraction-limited area, and wherein the array of pixels corresponds to at least the diffraction-limited area.

27. The system of claim 25, wherein the focal location includes a wide field of view, and wherein the array of pixels corresponds to at least the wide field of view.

28. The system of claim 25, wherein the focal location includes at least one diffraction-limited area selected from a wide field of view, the selected at least one diffraction-limited area having a fluorescent response with an intensity above a threshold, and wherein the array of pixels corresponds to at least the wide field of view.

30. The system of claim 26, wherein the control unit is further configured to:

adjust the frequency of the tunable microwave emitter to a first frequency, the first frequency corresponding to an m_s=+1 spin sublevel field splitting frequency of the at least one nitrogen vacancy center;

adjust the frequency of the tunable microwave emitter to a second frequency, the second frequency corresponding to a zero field splitting frequency of the at least one nitrogen vacancy center; and

adjust the frequency of the tunable microwave emitter to at least a third frequency, the third frequency corresponding to an m_s=−

1 spin sublevel field splitting frequency of the at least one nitrogen vacancy center.

31. The system of claim 30, wherein the control unit is further configured to:

receive from the photodetector a first intensity plot of a first fluorescent response corresponding to the first frequency;

receive from the photodetector a second intensity plot of a second fluorescent response corresponding to the second frequency; and

receive from the photodetector at least a third intensity plot of a third fluorescent response corresponding to the third frequency; and

wherein the first, second, and third intensity plots include a measurement of intensity of the fluorescent response over the array of pixels.

32. The system of claim 31, wherein the control unit is further configured to resolve the at least one nitrogen vacancy center based on by subtracting the first and third intensity plots from the second intensity plot.

33. The system of claim 23, wherein the light source includes a laser adapted to continuously irradiate the at least one nitrogen vacancy center with approximately 532 nm light.

34. The system of claim 23, wherein the light source is coupled to the control unit, and wherein the light source includes a laser adapted to apply a pulse of pump light at approximately 532 nm to the at least one nitrogen vacancy center prior to application of the at least one microwave pulse, and adapted to apply a pulse of pump light at approximately 532 nm to the nitrogen vacancy center subsequent to application of the at least one microwave pulse.

35. A method for resolving at least one deterministic emitter, comprising:

providing at least one structure with one or more deterministic emitters within a focal location, each being in either a dark state or a bright state;

applying a magnetic field across the at least one structure;

optically exciting the one or more deterministic emitters;

switching at least one deterministic emitter from the dark state to the bright state or from the bright state to the dark state by applying at least one microwave pulse to the one or more deterministic emitters;

detecting a fluorescent response of each deterministic emitter; and

resolving at least one of the deterministic emitters based on the fluorescent response of each deterministic emitter, the fluorescent response of each deterministic emitter corresponding to its orientation relative to the magnetic field.

36. The method of claim 35, wherein the at least one structure comprises at least one diamond structure and the one or more deterministic emitters comprises one or more nitrogen vacancy centers.

37. The method of claim 35, wherein the at least one structure comprises at least one silicon carbide structure and the one or more deterministic emitters comprises one or more silicon defects.