Super resolution and fast surface B-field imaging using an NV-diamond
View Patent ↗The present invention is directed to devices and systems for rapidly producing high resolution images of magnetic fields in a sample. The devices and systems employ diamond chips with color centers that fluoresce in the presence of magnetic fields. The high resolution is due to the use of one of three excitation methods. The first method employs modulation of an acoustic surface wave, which increases/decreases the sensitivity of the color centers to magnetic fields. The second and third methods employ arrays of magnetic field coils and electrode pairs, respectively, which again increase/decrease the sensitivity of the color centers to magnetic fields. The color centers are preferably nitrogen vacancies in the diamond chips.
1. A magnetic field imaging system, comprising:
a pump laser adapted to emit a pumping light beam having a pumping light beam wavelength;
a diamond chip, the diamond chip including:
a plurality of color centers, the plurality of color centers adapted to fluoresce in response to the pumping light beam and a magnetic field thereby creating fluorescence light; and
means for modulating a sensitivity of the plurality of color centers to the magnetic field, the sensitivity being modulated in two orthogonal directions, the means for modulating including two or more acoustic modulators, each acoustic modulator adapted to generate a corresponding acoustic standing wave in the diamond chip;
a photodetector adapted to receive the fluorescence light and to produce data corresponding to the fluorescence light; and
a signal processor adapted to receive the data and to convert the data into a corresponding magnetic-field image.
2. The magnetic field imaging system of claim 1 , wherein the pumping light beam wavelength is shorter than approximately 600 nm.
3. The magnetic field imaging system of claim 1 , wherein the diamond chip is formed on a substrate.
4. The magnetic field imaging system of claim 3 , wherein the substrate includes one of silicon, quartz, a metal, or a carbide.
5. The magnetic field imaging system of claim 1 , wherein the plurality of color centers includes a plurality of nitrogen vacancy centers.
6. The magnetic field imaging system of claim 1 , wherein the fluorescence light has a wavelength longer than approximately 650 nm.
7. The magnetic field imaging system of claim 1 , wherein each of the two or more acoustic modulators is a piezo transducer or a surface-acoustic-wave modulator.
8. The magnetic field imaging system of claim 1 , wherein the acoustic standing waves are one of longitudinal waves or transverse waves.
9. The magnetic field imaging system of claim 1 , wherein the means for modulating further includes a two-dimensional array of coils, each coil adapted to generate a corresponding submicron or nano-scale control magnetic field in the diamond chip.
10. The magnetic field imaging system of claim 1 , wherein the means for modulating further includes a two-dimensional array of electrode pairs, each electrode pair adapted to generate a corresponding pixelized control electric field in the diamond chip.
11. The magnetic field imaging system of claim 1 , wherein a ratio of a width of the photodetector to a distance between the diamond chip and the photodetector is between approximately 15 and approximately 25.
12. The magnetic field imaging system of claim 1 , further comprising a microwave source adapted to generate signals for driving the means for modulating.
13. The magnetic field imaging system of claim 1 , further comprising a long-pass filter located between the diamond chip and the photodetector, the long-pass filter adapted to pass the fluorescence light and block scattered pumping light beam.