CN111830073A

CN111830073A - High-flux single-molecule magnetic resonance measuring device and measuring method

Info

Publication number: CN111830073A
Application number: CN201910324002.9A
Authority: CN
Inventors: 王鹏飞; 蔡明诚; 郭忠智; 石发展; 杜江峰
Original assignee: University of Science and Technology of China USTC
Current assignee: University of Science and Technology of China USTC
Priority date: 2019-04-22
Filing date: 2019-04-22
Publication date: 2020-10-27
Anticipated expiration: 2039-04-22
Also published as: CN111830073B

Abstract

The embodiment of the invention discloses a high-flux single-molecule magnetic resonance measuring device and a measuring method, wherein laser emitted by a laser generating element in the measuring device is multi-point exciting light, and the phases of the multi-point exciting light are not completely the same, so that when an NV color center in a diamond sample is excited, a plurality of NV color centers on a light path of the multi-point exciting light can be excited simultaneously, a plurality of NV color centers can be measured at one time, and the measuring efficiency is improved. In addition, the light spot formed by the excitation light of each point of the device is small, so that when a plurality of NV color centers in the diamond sample are excited, the area irradiated by the excitation light of each point is small, a single NV color center is used as a magnetic resonance sensing unit, the spatial resolution is high, and the signal measurement of a single molecule is further realized.

Description

High-flux single-molecule magnetic resonance measuring device and measuring method

Technical Field

The invention relates to the technical field of magnetic resonance measurement, in particular to a high-flux single-molecule magnetic resonance measurement device and a measurement method.

Background

Nitrogen-vacancy defect centers (NV centers for short) in diamond have proven to be a significant advantage in nanoscale magnetic field detection, such as: the electron spin freedom of the NV color center can be regulated and controlled by microwaves, and is initialized and read out by an optical means; the coherence time of the NV colour center at room temperature can be as long as milliseconds; the NV color center is a point defect in the diamond, the size of the NV color center is only in the angstrom level, and the positioning precision can reach the nanometer level under a confocal system.

In 2015, the magnetic resonance spectrum of the first single protein molecule was measured by NV color center in room temperature atmosphere environment (see Science 347, 1135(2015)) by stone development, sachi, royal pengfei and other people, and the measurement method thereof firstly realizes nano-scale single molecule magnetic resonance detection, and comprises the following steps: randomly throwing protein molecules on the surface of the diamond, wherein the protein molecules are stochastically close to NV color centers; and measuring a large amount of NV color center signals, wherein if the protein molecule to be detected happens to be in the NV color center range, the labels such as nitrogen-oxygen free radicals on the protein molecule to be detected and the NV color center generate dipole-dipole interaction, the population degree of the NV color center is changed, so that the signals of the protein molecule to be detected can be obtained by reading the population of the NV color center through fluorescence, and finally the magnetic resonance of the protein molecule close to the NV color center is measured. However, the conventional magnetic resonance spectrum measuring device based on the NV color center has low measuring efficiency.

Disclosure of Invention

In order to solve the above technical problems, embodiments of the present invention provide a high-throughput single-molecule magnetic resonance measurement apparatus and a measurement method, which can simultaneously measure signals of multiple NV color centers, and implement synchronous collection of fluorescence signals of multiple NV color centers, thereby improving measurement efficiency of the measurement apparatus.

In order to solve the above problems, the embodiments of the present invention provide the following technical solutions:

a high-throughput single-molecule magnetic resonance measurement apparatus, comprising:

a laser generating element that generates multi-point excitation light whose phases are not completely the same;

a sensing probe element comprising a diamond sample having a plurality of NV colour centers, the plurality of NV colour centers in the diamond sample producing a fluorescent signal under excitation by the excitation light;

the fluorescence collection element is used for collecting fluorescence signals generated by the plurality of NV color centers under the excitation of the excitation light and distinguishing the fluorescence signals corresponding to different NV color centers;

a position adjusting element for adjusting a position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element such that a color center plane of the diamond sample coincides with the multi-point excitation light plane and an optical path direction of fluorescence of the diamond sample is perpendicular to a light sensing plane of the fluorescence collecting element;

the microwave magnetic field generating element is used for generating a preset magnetic field and a preset microwave field, the magnetic field direction of the preset magnetic field is coincident with the NV axis of the diamond sample, and the preset microwave field is used for controlling the quantum state of the NV color center in the diamond sample.

Optionally, all NV colour centers in the diamond sample are distributed within a distance of 20 nm from the surface of the diamond sample.

Optionally, a distance between any two NV color centers in the plurality of NV color centers along a first direction is less than 10 nm, and a distance between any two NV color centers along a second direction is greater than an optical diffraction limit of the system, wherein the first direction is perpendicular to a surface of the diamond, and the second direction is parallel to the surface of the diamond.

Optionally, the laser generating element includes: the device comprises a laser, an optical isolator, a first polaroid, an acousto-optic modulator group, a beam expanding system, a spatial light modulator and a first lens system, wherein the laser is used for generating first exciting light; the optical isolator is used for blocking exciting light on one side of the optical isolator, which faces away from the laser, from entering the laser through reflection; the first polaroid is used for adjusting the polarization direction of the first exciting light to a first polarization direction; the acousto-optic modulator group is used for controlling the on-off of the first exciting light; the beam expanding system is used for amplifying the light spot of the first exciting light to form a first light spot, so that the first light spot covers the whole target surface of the spatial light modulator; the spatial light modulator is used for modulating the phase of the first exciting light to form second exciting light with a plurality of phases; the first lens system is used for generating the multi-point excitation light based on the second excitation light of a plurality of phases output by the spatial light modulator.

Optionally, the acousto-optic modulator group includes: a plurality of acousto-optic modulators to control switching of the first excitation light.

Optionally, the first lens system includes: the first lens is used for converging the second excitation light with multiple phases, the light filtering structure is located on a focal plane of the first lens and used for blocking zero-order diffraction light in emergent light of the first lens and filtering out the zero-order diffraction light in the converged second excitation light to form third excitation light, the second lens is used for converting the third excitation light into parallel fourth excitation light to be emitted, the dichroic mirror is used for changing the transmission direction of the fourth excitation light to enable the fourth excitation light to enter the objective lens, and the objective lens is used for forming multi-point excitation light to be emitted based on the fourth excitation light.

Optionally, the method for determining the positions of all NV color centers in the diamond sample within the current visual field range comprises:

dividing the current visual field range into n areas with the same shape and size, and generating n laser light spots by using the spatial light modulator, wherein each area is provided with only one laser light spot, and the relative positions of the light spots in the respective areas are the same; and changing the phase of the spatial light modulator to enable the laser spot in each area to simultaneously scan the respective area, marking and outputting when an NV color center is scanned in the scanning process, and recording the position of the NV color center to obtain the position of each NV color center in the current view field.

Optionally, the position adjusting element comprises at least one of a first position adjusting element, a second position adjusting element and a third position adjusting element, wherein the first position adjusting element is used for adjusting at least one of the position and the angle of the sensing probe element in a preset coordinate system, the second position adjusting element is used for adjusting at least one of the position and the angle of the laser generating element in the preset coordinate system, and the third position adjusting element is used for adjusting at least one of the position and the angle of the fluorescence collecting element in the preset coordinate system; wherein the first position adjustment element comprises: the angle adjusting element comprises an angle adjusting knob and a rotary bearing plate used for fixing the angle adjusting knob, and the spatial position adjusting element is fixed on the rotary bearing plate and used for adjusting the position of the sensing probe element in the preset coordinate system along the direction X, Y, Z, and the angle adjusting knob is used for adjusting the angle of the sensing probe element in the preset coordinate system.

A high-throughput single-molecule magnetic resonance measurement method is applied to any one of the high-throughput single-molecule magnetic resonance measurement devices, and comprises the following steps:

fixing a sensing probe element carrying a molecule to be measured on a position adjustment element, the sensing probe element comprising a diamond sample having a plurality of NV colour centers;

controlling a laser generating element to generate multi-point exciting light, wherein the phases of the multi-point exciting light are not completely the same;

adjusting the position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element so that the color center plane of the diamond sample coincides with the multi-point excitation light plane and the optical path direction of the fluorescence signal of the diamond sample is perpendicular to the light sensing plane of the fluorescence collecting element;

controlling a microwave magnetic field generating element to generate a preset magnetic field and a preset microwave field, enabling the magnetic field direction of the preset magnetic field to be coincident with the NV axis of the diamond sample, and controlling the quantum state of the NV color center in the diamond sample by using the preset microwave field;

performing at least once a measurement data collection step, the measurement data collection step comprising: forming multi-point exciting light by using the laser generating element and emitting the multi-point exciting light to the sensing probe element, wherein a plurality of NV color centers in the diamond sample generate fluorescent signals under the excitation of the exciting light; and collecting fluorescence signals generated by the plurality of NV color centers under the excitation of the exciting light by using the fluorescence collecting element, and distinguishing the fluorescence signals corresponding to different NV color centers to obtain experimental data.

Optionally, the measurement method includes:

under a third preset condition, judging whether the NV color center count collected by the fluorescence collecting element is less than a preset number;

if the fluorescence count of the NV color center acquired by the fluorescence collecting element is smaller than a preset count, adjusting the position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element until the fluorescence count of the NV color center acquired by the fluorescence collecting element is not smaller than the preset count;

and if the fluorescence count of the NV color center acquired by the fluorescence collecting element is not less than the preset count, continuing to execute the step of acquiring the measured data.

Optionally, the adjusting the position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element until the fluorescence count of the NV color center acquired by the fluorescence collecting element is not less than a preset count includes:

taking the position of the NV color center recorded by NV color center scanning as a center, changing the phase of the spatial light modulator, moving an excitation light point, scanning two mutually perpendicular directions in sequence, and recording the sum of fluorescence counts of the NV color center obtained on the fluorescence collection element after each movement;

after scanning is finished, adjusting the phase of the spatial light modulator to a phase corresponding to the maximum fluorescence counting sum of the NV color center;

repeating the above process for several times until the fluorescence count of the NV color center meets a first preset condition, and completing the phase drift calibration of the spatial light modulator and the calibration of the thermal drift in the horizontal direction;

and/or the presence of a gas in the gas,

controlling the first position adjustment element to move the sensing probe element in a vertical direction to calibrate thermal drift in the vertical direction, the first position adjustment element reading a sum of fluorescence counts of all NV color centers via the fluorescence collection element once per movement;

and moving the first position adjusting element to a position where the sum of the fluorescence counts of all the NV color centers is maximum, repeating the process for a plurality of times until the fluorescence counts of the NV color centers meet a second preset condition, and finishing the calibration of the thermal drift in the vertical direction.

Compared with the prior art, the technical scheme has the following advantages:

according to the high-flux single-molecule magnetic resonance measuring device provided by the embodiment of the invention, the laser emitted by the laser generating element is the multi-point exciting light, and the phases of the multi-point exciting light are not completely the same, so that when the NV color centers in the diamond sample are excited, a plurality of NV color centers on the light path of the multi-point exciting light can be excited simultaneously, a plurality of NV color centers can be measured at one time, and the measuring efficiency is improved.

In addition, in the measuring device provided by the embodiment of the invention, the laser emitted by the laser generating element is multi-point excitation light, and the light spot formed by each point of excitation light is small, so that when a plurality of NV color centers in the diamond sample are excited, the area irradiated by each point of excitation light is small, a single NV color center is used as a magnetic resonance sensing unit, the spatial resolution is high, and the signal of a single molecule is measured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a high-throughput single-molecule magnetic resonance measurement apparatus according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a laser generating device according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a first lens system based on a spatial light modulator for generating multi-point excitation light according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the division of regions within the current field of view and their internal color center locations;

FIG. 5 is a schematic diagram illustrating calibration of NV color center positions for regions within a current field of view;

FIG. 6 is a schematic structural diagram of a fluorescence collection element according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a first position adjustment element according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a microwave magnetic field generating element according to an embodiment of the present invention;

FIG. 9 is a schematic diagram illustrating the position of a sensing probe element and a uniform radiation structure according to an embodiment of the present invention;

FIG. 10 is a flow chart of a high throughput single molecule MR measurement method according to an embodiment of the present invention;

FIG. 11 is a flowchart illustrating a step of performing at least one measurement data acquisition according to an embodiment of the present invention;

fig. 12 is a schematic diagram of a square wave sequencer controlling the combination of the acousto-optic modulator in the laser generating element, the fluorescence detector in the fluorescence collecting element, and the microwave switch structure in the microwave magnetic field generating element according to the embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

As described in the background section, the conventional NV-color-center-based magnetic resonance spectrum measuring apparatus has low measurement efficiency.

The inventor researches and discovers that the existing magnetic resonance spectrum measuring device based on the NV color center is based on a traditional optical detection magnetic resonance confocal system, excitation light of 532 nanometers is converged on the single NV color center, fluorescence generated by the NV color center is filtered through a rear end pinhole and then collected by an avalanche breakdown diode.

Moreover, since the signal of a single molecule is weak, a single measurement (i.e., measurement of a single NV color center) requires a day or more to obtain an accurate magnetic resonance spectrum, which also makes the conventional NV color center-based magnetic resonance spectrum measurement apparatus inefficient.

In addition, when the protein molecules are randomly thrown to the surface of the diamond and are stochastically close to the NV color center, the single protein molecule cannot be accurately bound to the vicinity of the single NV color center, so that most of NV color centers are usually free of molecules to be detected in an effective detection range, meaningless measurement is caused, and further the measurement efficiency is low.

What is worse, in the measurement process, because the protein molecules to be measured are positioned on the surface of the diamond and are separated from the environment of the salt buffer solution, the shelf life of the protein molecules to be measured is greatly shortened, the protein molecules to be measured generally deteriorate for about two weeks, and the measurement signals disappear, so that the conventional measurement device can only measure signals of a plurality of NV color centers in the shelf life of the protein to be measured, and the measurement efficiency is further reduced.

The inventor finds that, in 2018, a high-flux NV color center-based magnetic resonance measurement device is used in Nature volume555, pages 351-354 (15March2018), the magnetic resonance measurement device adopts a total internal reflection path, an ensemble NV color center is used as a sensing probe element, laser with the diameter of 10 microns is used as excitation light for exciting the NV color center, fluorescence generated by the NV color center is collected by a photomultiplier tube, a sample to be measured is combined on the surface of a diamond during a specific experiment, the NV color center of a combination area of the diamond and the sample to be measured is initialized and read by the excitation light with a wide field, and polarization signals or fluctuation signals of nuclei such as hydrogen nuclei in the sample can be measured by a specific sequence. The device gives full play to the advantages of strong fluorescence signal and high detection sensitivity of the ensemble NV probe, and can rapidly measure the magnetic resonance spectrum of the molecules to be measured on the surface of the diamond sample. However, the spatial excitation scale of the excitation and collection optical path in the device is in the micrometer scale, so that all NV color centers in the micrometer scale are excited simultaneously, and when the NV color centers in the micrometer scale are used as the magnetic resonance sensing unit, the spatial resolution is in the micrometer scale, and the signal of a single molecule cannot be measured.

In view of this, the embodiment of the present invention provides a high-throughput single-molecule magnetic resonance measurement apparatus. As shown in fig. 1, the measuring apparatus for high-throughput single-molecule magnetic resonance comprises:

a laser generating element 100 that generates multi-spot excitation light whose phases are not completely the same or even completely different;

a sensing probe element 200 comprising a diamond sample having a plurality of NV colour centers, the plurality of NV colour centers in the diamond sample producing a fluorescent signal upon excitation by the excitation light;

a fluorescence collecting element 300, configured to collect fluorescence signals generated by the plurality of NV color centers under excitation of the excitation light, and distinguish fluorescence signals corresponding to different NV color centers;

a position adjusting element 400 for adjusting a position of at least one of the laser generating element 100, the sensing probe element 200 and the fluorescence collecting element 300 such that a color center plane of the diamond sample coincides with the multi-point excitation light plane and an optical path direction of fluorescence of the diamond sample is perpendicular to a light sensing plane of the fluorescence collecting element 300;

the microwave magnetic field generating element 500 is used for generating a preset magnetic field and a preset microwave field, the magnetic field direction of the preset magnetic field is coincident with the NV axis of the diamond sample, and the preset microwave field is used for controlling the quantum state of the NV color center in the diamond sample, wherein the quantum state of the NV color center comprises a ground state and an excited state.

It should be noted that, in the embodiment of the present invention, the plurality of NV color centers in the diamond sample are not necessarily all on the same plane, if the plurality of NV color centers in the diamond sample are distributed on different planes, the color center plane is a plane including the largest number of NV color centers in the diamond sample, and if the plurality of NV color centers in the diamond sample are distributed on the same plane, the color center plane is a plane where the plurality of NV color centers in the diamond sample are located.

It should be further noted that, in the embodiment of the present invention, the NV axis direction of the diamond sample is fixed, and therefore, in an embodiment of the present invention, one way of achieving the coincidence between the magnetic field direction of the preset magnetic field and the NV axis of the diamond sample includes: and adjusting the preset magnetic field to scan the continuous wave spectrum, wherein if two peaks of the continuous wave spectrum are symmetrical about 2870MHz, the magnetic field direction of the preset magnetic field is coincided with the NV axis of the diamond sample at the moment.

In specific operation, the electron energy level of the NV color center in the diamond sample is excited to an excited state from a ground state by multi-point excitation light generated by the laser generating element, and due to the excited state energy level structure specific to the NV color center, fluorescence corresponding to the layout number of the ground state energy levels is emitted when the electron energy level of the NV color center falls back to the ground state from the excited state.

As can be seen from the above, in the measuring device provided in the embodiment of the present invention, the laser emitted by the laser generating element is the multi-point excitation light, and the phases of the multi-point excitation light are not completely the same, so that when the NV color centers in the diamond sample are excited, the NV color centers located on the optical path of the multi-point excitation light can be excited simultaneously, a plurality of NV color centers can be measured at one time, and the measurement efficiency is improved.

On the basis of any of the above embodiments, in one embodiment of the present invention, as shown in fig. 2, the laser generating element includes: the device comprises a laser 111, an optical isolator 112, a first polarizer 113, an acousto-optic modulator group 114, a beam expanding system 115, a spatial light modulator 116 and a first lens system 117, wherein the laser 117 can be selected from high-power lasers and is used for generating first excitation light; the optical isolator 112 is used for blocking excitation light on the side, away from the laser 111, of the optical isolator 112 from entering the laser 111, so that the laser 111 is damaged; the first polarizer 113 is configured to adjust the polarization direction of the first excitation light to a first polarization direction; the acousto-optic modulator group 114 is used for controlling the switch of the first exciting light; the beam expanding system 115 is configured to amplify the light spot of the first excitation light to form a first light spot, so that the first light spot covers the entire target surface of the spatial light modulator 116; the spatial light modulator 116 is configured to modulate a phase of the first excitation light to form a second excitation light having a plurality of phases; the first lens system 117 is configured to generate multi-point excitation light based on the second excitation light with multiple phases output by the spatial light modulator 116, and the phases of the multi-point excitation light are not completely the same.

Therefore, in the measurement apparatus provided by the embodiment of the present invention, the second excitation light with multiple phases formed by the spatial light modulator passes through the first lens system (i.e., undergoes fourier transform) to form multiple multi-point excitation lights with smaller light spots, so that when multiple NV color centers in the diamond sample are excited, an area irradiated by each point of the excitation light is smaller, a single NV color center is used as a magnetic resonance sensing unit, spatial resolution is higher, and thus, measurement of a signal of a single molecule is achieved.

Optionally, the laser is a high-power laser capable of generating first excitation light of 1 watt level, specifically, the first excitation light is laser light of 532 nm wavelength, in other embodiments of the present invention, the first excitation light may also be laser light of other wavelengths, and as the case may be, the present invention is not limited to this specifically.

Optionally, the first polarizer is a half-wave plate, the half-wave plate adjusts the polarization direction of the first excitation light emitted to the first polarizer to a first polarization direction, the first polarization direction is the most suitable direction of the acousto-optic modulator group, that is, the most sensitive direction of the acousto-optic modulator group, for example, when the acousto-optic modulator group is sensitive to the polarization direction of light, generally, when the first polarization direction is the vertical direction, the utilization efficiency of the acousto-optic modulator group on the first excitation light is the highest, and when the acousto-optic modulator is not sensitive to the polarization direction of light, the preset direction is determined according to the actual situation.

It should be noted that the utilization efficiency of the first laser light generated by the laser light generating element by the measuring device is mainly determined by the efficiencies of the acousto-optic modulator group and the spatial light modulator. In the embodiment of the invention, the measuring device utilizes a high-efficiency mode that the spatial light modulator generates a plurality of excitation light points based on parallel excitation light, and the utilization efficiency of laser can approach or reach 50%.

Specifically, on the basis of the above embodiment, in an embodiment of the present invention, the acousto-optic modulator group includes: a plurality of acousto-optic modulators, thereby controlling the on-off of the first excitation light by adopting the plurality of acousto-optic modulators to improve the on-off ratio of the first excitation light, and optionally, the on-off ratio of the acousto-optic modulator group is more than or equal to 10⁷:1. It should be noted that the on-off ratio refers to a ratio of the transmission light intensity in the on state to the transmission light intensity in the off state, and a larger ratio indicates a better switching performance of the aom group. In addition, it should be noted that the switching ratios of different acousto-optic modulator groups are different, and the acousto-optic modulator groups includeThe larger the number of acousto-optic modulators, the larger the on-off ratio.

In the embodiment of the present invention, the incident light of the first acousto-optic modulator in the plurality of acousto-optic modulators is the first excitation light having the first polarization direction emitted by the first polarizer, and the incident lights of the other acousto-optic modulators along the optical path direction of the first excitation light all use the first order diffracted light generated by the previous adjacent acousto-optic modulator as the incident light.

Specifically, in an embodiment of the present invention, the set of acousto-optic modulators 114 includes 3 acousto-optic modulators, which are respectively a first acousto-optic modulator, a second acousto-optic modulator and a third acousto-optic modulator, where incident light of the first acousto-optic modulator is first excitation light with a first polarization direction emitted from a first polarizer, incident light of the second acousto-optic modulator is first-order diffracted light generated by the first acousto-optic modulator, and incident light of the third acousto-optic modulator is first-order diffracted light generated by the second acousto-optic modulator, so as to implement greater than 10⁷On-off ratio of 1.

It should be noted that, in the above embodiment, the operating state of each acousto-optic modulator in the acousto-optic modulator group may be controlled by an external square wave generator, or a square wave generator may be provided in the measuring apparatus and controlled by an internal square wave generator, which is not limited in this respect, and is determined as the case may be.

It should also be noted that the delay between different acousto-optic modulators in the set of acousto-optic modulators can be calibrated by subsequent fluorescence collection elements.

On the basis of any of the above embodiments, in an embodiment of the present invention, the beam expanding system 115 may be a lens group, and in other embodiments of the present invention, the beam expanding system 115 may also be a beam expander, which is not limited in this respect, and is determined as the case may be. In the embodiment of the present invention, the specific amplification factor of the beam expanding system for the light spot of the first excitation light is determined by the light spot size of the first excitation light generated by the laser, the target surface of the spatial light modulator and the tolerance power of the spatial light modulator, so long as it is ensured that the first excitation light can cover the entire target surface of the spatial light modulator after passing through the beam expanding system, and the power density is less than the highest power density tolerated by the spatial light modulator.

On the basis of any of the above embodiments, the spatial light modulator modulates the phase of the first excitation light to generate second excitation light having a plurality of phases based on the first excitation light.

In addition to any of the above embodiments, in an embodiment of the present invention, as shown in fig. 2, the first lens system 117 includes: the excitation light source device comprises a first lens 1171, a light filtering structure 1172, a second lens 1173, a dichroic mirror 1174 and an objective lens 1175, wherein the first lens 1171 is used for converging second excitation light with multiple phases, the light filtering structure 1172 is located on a focal plane of the first lens 1171 and is used for blocking zero-order diffraction light in emergent light of the first lens 1171 and filtering out the zero-order diffraction light in the converged second excitation light to form third excitation light, the second lens 1173 is used for converting the third excitation light into parallel fourth excitation light to be emitted, the dichroic mirror 1174 is used for changing the transmission direction of the fourth excitation light to enable the fourth excitation light to enter the objective lens 1175, the objective lens 1175 is used for forming multi-point excitation light to be emitted based on the fourth excitation light, and the process is equivalent to that the fourth excitation light is subjected to one-time Fourier change. Note that the zero-order diffracted light in the second excitation light is generated by a spatial light modulator. Optionally, the filtering structure 1172 is a light barrier.

The objective lens 1175 in the above embodiment is located on the same plane as the first lens 1171, the filter structure 1172, the second lens 1173, and the dichroic mirror 1174.

In other embodiments of the present invention, when the objective lens 1175 is not in the same plane as the first lens 1171, the filtering structure 1172, the second lens 1173, and the dichroic mirror 1174, that is, the objective lens 1175 is perpendicular to the plane where the first lens 1171, the filtering structure 1172, the second lens 1173, and the dichroic mirror 1174 are located, at this time, the first lens system 117 further includes a reflecting mirror located between the dichroic mirror 1174 and the objective lens 1175, wherein the first lens 1171 is configured to converge the second excitation light with multiple phases, the filtering structure 1172 is located on the focal plane of the first lens 1171, and is configured to block the zero-order diffracted light in the light emitted from the first lens 1171, form third excitation light by filtering the zero-order diffracted light in the converged second excitation light, the second lens 1173 is configured to convert the third excitation light into parallel fourth excitation light, and the dichroic mirror 1174 is configured to change the transmission direction of the fourth excitation light, forming fifth excitation light, wherein the reflecting mirror is used for changing the transmission direction of the fifth excitation light to enable the fifth excitation light to enter an objective lens 1175, the objective lens 1175 is used for forming multi-point excitation light emission based on the fifth excitation light, and the process is equivalent to Fourier change of the fifth excitation light once. Note that the zero-order diffracted light in the second excitation light is generated by a spatial light modulator. Optionally, the filtering structure 1172 is a light barrier. The principle of the first lens system generating multi-point excitation light based on the second excitation light with multiple phases output by the spatial light modulator is described below with reference to an optical path diagram, where a plane of the multi-point excitation light is a focal plane of an objective lens in the first lens system.

Specifically, as shown in fig. 3, the plane where the coordinates (x, y) are located is the NV color center plane, i.e. the focal plane 301 of the objective lens, and the complex amplitude of the two laser spots located on the focal plane 301 of the objective lens is expressed as:

wherein x is₁X-axis coordinates representing laser spot 1 on objective focal plane 301; y is₁Y-axis coordinates representing laser spot 1 on objective focal plane 301; x is the number of₂X-axis coordinates representing the laser spot 2 on the objective focal plane 301; y is₂To representThe y-axis coordinate of the laser spot 2 on the objective focal plane 301;

represents the phase of the corresponding excitation light at excitation light point 1;

represents the phase of the corresponding excitation light at the excitation light point 2;

the light field at the pupil plane of objective 1175 should be the inverse fourier transform of g (x, y), which can be expressed as

Wherein u is₁X-axis coordinates representing a first pre-set point of the front focal plane of objective 1175; v. of₁Y-axis coordinates representing a first pre-set point of the front focal plane of objective 1175; f. of₃Represents the focal length of objective lens 1175; the first pre-set point is any point on the front focal plane of the objective 1175.

The light field at the front focal plane of the second lens 1173 should be F^-1The inverse Fourier transform of { g (x, y) }, which can be expressed as

Wherein u is₂X-axis coordinates representing a second preset point of the front focal plane of the second lens 1173; v. of₂Y-axis coordinates representing a second pre-set point of the front focal plane of the second lens 1173; f. of₂Denotes the focal length of the second lens; the second preset point is any point on the front focal plane of the second lens 1173;

the light field at the front focal plane of the first lens 1171 should be F^-1{F^-1An inverse Fourier transform of { g (x, y) } into

Wherein u is₃X-axis coordinate representing third pre-set point of front focal plane of first lens 1171Marking; v. of₃Y-axis coordinates representing a third pre-set point of the front focal plane of the first lens 1171; f. of₁Denotes the focal length of the first lens 1171; the third predetermined point is any point on the front focal plane of the first lens 1171.

As can be seen from the above formula, the transmitted (or reflected) optical field on the Spatial Light Modulator (SLM) 116 has two Spatial frequencies in both x and y directions, which are:

wherein k is_x1Indicating that excitation light point 1 corresponds to the phase in the x-axis direction on the spatial light modulator 116;

K_y1indicating that excitation light point 1 corresponds to the phase in the y-axis direction on the spatial light modulator 116;

K_x2indicating that excitation light point 2 corresponds to the phase in the x-axis direction on the spatial light modulator 116;

K_y2indicating that excitation light point 2 corresponds to the phase in the y-axis direction on the spatial light modulator 116;

the square of a represents the light intensity.

It should be noted that, in the actual optical path, a light-blocking plate is disposed on the confocal plane between the first lens and the second lens, and the light-blocking plate is used for blocking the zero-order diffracted light.

As can be seen from the above calculation, the multi-point excitation light of the NV color center plane corresponds to the second excitation light of multiple phases output by the spatial light modulator, and the spatial light modulator can adjust the phase of the multi-point excitation light by adjusting the phase of the first excitation light, so as to form multi-point excitation light having multiple phases, so as to generate multi-point excitation light matched with each NV color center.

It should be noted that, unlike single-molecule magnetic resonance devices and wide-field excitation devices with single-point excitation, the measurement device provided in the embodiment of the present invention needs to accurately find the respective positions of all NV color centers in the field of view before the experiment, so as to generate multi-point excitation light matched with each NV color center.

Specifically, in one embodiment of the present invention, the method for determining the positions of all NV color centers in the diamond sample within the current field of view comprises:

as shown in fig. 4, the current field of view is divided into n regions (e.g., n equal-sized square regions) with the same shape and size, and n laser spots are generated by using the spatial light modulator, wherein each region has one and only one laser spot, and the relative positions of the spots in the respective regions are the same; and changing the phase of the spatial light modulator to enable the laser spot in each area to simultaneously scan the respective area, marking and outputting when an NV color center is scanned in the scanning process, and recording the position of the NV color center to obtain the position of each NV color center in the current visual field range, so that the position of each single NV color center in the diamond is accurately positioned.

It can be known from the above method that the measuring device provided in the embodiment of the present invention can find the positions of all NV color centers in the current visual field range only by one scanning, and then input the positions of all NV color centers into the spatial light modulator, and encode the phase of the spatial light modulator, so as to generate multi-point excitation light matched with the NV color centers of the colors.

Specifically, in an embodiment of the present invention, after obtaining the positions of all NV color centers in the field of view, inputting the map recorded with the positions of all NV color centers into a spatial light modulator, where the spatial light modulator may generate a corresponding phase grayscale map through an algorithm, and after fourier transform, may generate a dot matrix (i.e., multi-point excitation light) that simultaneously excites all NV color centers, and then adjust the angles of the diamond sample and the spatial light modulator, and simultaneously observe the count of the NV color centers, and if the NV color center count reaches a maximum, it indicates that the NV color center plane and the multi-point excitation light plane coincide.

In the experimental process, the NV color center inevitably deviates from the corresponding excitation light spot due to thermal drift or phase shift of the spatial light modulator, so that the fluorescence count of the NV color center decreases. In addition, the measurement apparatus provided in the embodiment of the present invention may further calibrate a phase shift of a liquid crystal modulation unit of the spatial light modulator and a deviation phenomenon of an NV color center from an excitation light spot corresponding to the NV color center caused by a thermal shift of the measurement apparatus by changing a modulation phase of the spatial light modulator and/or a position of the sensing probe element, specifically, as shown in fig. 5, the calibration method includes:

taking the position of the NV color center recorded by NV color center scanning as a center, changing the phase (such as an additional phase) of the spatial light modulator, moving an excitation light point, scanning two mutually perpendicular directions in sequence, optionally, the total distance of movement in each direction is about 1 micrometer, the step length of single movement is 10 nanometers, recording the total sum of fluorescence counts of the NV color center obtained on a fluorescence collection element after each movement, optionally, the movement track is in a cross shape, for example, moving along a transverse line in the cross shape and then moving along a vertical line in the cross shape;

after the scanning is finished, adjusting the phase of the spatial light modulator to the phase corresponding to the maximum fluorescence counting sum of the NV color center;

the above process is repeated for several times until the fluorescence count of the NV color center meets a first preset condition, and then the phase drift calibration of the spatial light modulator and the thermal drift calibration in the horizontal direction can be completed.

On the basis of the above embodiment, in an embodiment of the present invention, the calibration method further includes:

after the calibration is completed, controlling the position adjusting element to move the sensing probe element in the vertical direction so as to calibrate the thermal drift in the vertical direction, and reading out the sum of the fluorescence counts of all NV color centers through the fluorescence collecting element once when controlling the position adjusting element to move; and finally, moving the control position adjusting element to the position where the number of the fluorescence counts of all the NV color centers is the maximum, repeating the process for a plurality of times until the number of the fluorescence counts of the NV color centers meets a second preset condition, and finishing the calibration of the thermal drift in the vertical direction.

It should be noted that each movement of the position adjustment element is controlled by one step, and the size of one step is determined according to the actual situation, for example, 40 steps in the vertical direction, and a total distance of 5um is moved, so that one step is 0.125 μm.

It should be noted that, in the above embodiment, the first preset condition and the second preset condition may be the same or different, and for example, both the first preset condition and the second preset condition may be that the fluorescence count of the NV color center returns to the initial value or satisfies a certain value, for example, the certain value is greater than or equal to 70% of the initial value. The present invention is not limited in this regard, as the case may be.

In one embodiment of the present invention, the diamond sample has a length of greater than or equal to 100 microns and a width of greater than or equal to 100 microns. Specifically, the length of the diamond sample is greater than or equal to 2 mm, and the width is greater than or equal to 2 mm, but the invention is not limited thereto, as the case may be. On the basis of the above embodiment, in an embodiment of the present invention, the distribution distance of all NV color centers in the diamond sample is within 20 nanometers of the surface of the diamond sample, so as to avoid weak dipole-dipole interaction between the NV color centers and the molecules to be measured, so that the measurement signal corresponding to a single molecule to be measured is too small, which results in a large amount of time required for obtaining the measurement signal, or even the measurement signal cannot be obtained. It should be noted that most of the NV colour centers in the diamond samples lie substantially in the same plane parallel to the diamond surface, and only a few of the diamond samples do not lie in this plane.

On the basis of the above embodiment, in an embodiment of the present invention, a distance between any two color centers of the NV color centers in the diamond sample along the first direction is less than 10 nanometers, and a distance between any two color centers along the second direction is greater than an optical diffraction limit of a system, so that when multiple points of excitation light emitted by the laser generating element excite multiple NV color centers in the diamond sample, each excitation point excites only one NV color center, and mutual interference between adjacent NV color centers is reduced. Wherein the first direction is perpendicular to the goldA surface of a diamond, the second direction being parallel to the diamond surface. The formula of the optical diffraction limit d is:

λ is the wavelength of the excitation light, and NA is the numerical aperture of the objective lens.

Optionally, the number of single NV color centers in the diamond sample may be from 1 to a maximum value allowed by the measurement device, where the maximum value of the number of color centers allowed by the measurement device is determined by a resolution of the spatial light modulator, for example, in an embodiment of the present invention, the spatial light modulator can achieve synchronous excitation of at most 1000 NV color centers, and then the maximum value allowed by the number of single NV color centers in the diamond sample is 1000, but the present invention is not limited thereto, and is determined by the resolution of the spatial light modulator.

On the basis of the above embodiments, in an embodiment of the present invention, the sensing probe element may include a diamond sample with a flat surface, and may also include a diamond sample with an optical waveguide structure on a surface, so as to improve fluorescence counting of NV color centers, amplify measurement signals, and shorten measurement time. The optical waveguide structure is obtained by micro-nano processing on the surface of a diamond sample, and specifically, the optical waveguide structure can be a diamond nano-column structure, which is not limited in the application and is specifically determined according to the situation.

Optionally, on the basis of the above embodiment, in an embodiment of the present invention, when the surface of the diamond sample is flat, the fluorescence count (i.e., the fluorescence count of a single NV color center) collected by the fluorescence detector after the single NV color center of the diamond sample is excited by the excitation light is greater than 10000 photons/second, and when the surface of the diamond sample has the diamond nanopillar, the fluorescence count (i.e., the fluorescence count of a single NV color center) collected by the fluorescence detector after the single NV color center of the diamond sample is excited by the excitation light is greater than 100000 photons/second.

On the basis of any of the above embodiments, in one embodiment of the present invention, as shown in fig. 6, the fluorescence collecting element includes: a second lens system 311, an imaging system 312, a multi-stage filter 313 and a fluorescence detector 314.

In specific operation, as shown in fig. 6, the fluorescence signal generated by the sensing probe element 200 is emitted to the objective 1175 in the laser generating element, is emitted to the dichroic mirror 1174 after being collected by the objective 1175, is emitted to the second lens system 311 of the fluorescence collecting element after being transmitted by the dichroic mirror 1174, and the second lens system 311 is used for blocking the fluorescence signal generated when the NV color center is initialized, and optionally includes a third lens 3111, an optical chopper 3112 and a fourth lens 3111, wherein the focal lengths of the third lens 3111 and the fourth lens 3113 are equal; the imaging system 312 is used for imaging based on the emergent light of the second lens system 311, and can be selected as an imaging lens; the multi-stage filter 313 is configured to filter excitation light of 532 nm in the emergent light of the second lens system 311 and a background fluorescence signal not in the NV color center fluorescence band, and optionally, the multi-stage filter sequentially includes a first filter 3131, a second filter 3132, and a third filter 3133 along a direction of a light path of 313 fluorescence, where the first filter 3131 is an 800nm short-pass filter, the second filter 3132 is a 635nm long-pass filter, and the third filter 3133 is a 532 nm green filter; the fluorescence detector 314 is configured to collect the fluorescence signals transmitted by the multistage optical filter 313, and optionally, the fluorescence detector 314 is a fluorescence detector 314 capable of spatially distinguishing fluorescence signals of different NV color centers, and a wavelength band of the fluorescence detector 314 covers 600 nm to 800nm, such as an electronic coupling Device (CCD), an avalanche breakdown diode array, a complementary metal oxide semiconductor structure, and the like, where the electronic coupling Device includes an electronic coupling camera.

On the basis of any one of the above embodiments, in one embodiment of the present invention, the position adjusting element includes at least one of a first position adjusting element for adjusting at least one of a position and an angle of the sensing probe element in a preset coordinate system, a second position adjusting element for adjusting at least one of a position and an angle of the laser generating element in a preset coordinate system, and a third position adjusting element for adjusting at least one of a position and an angle of the fluorescence collecting element in a preset coordinate system.

It should be noted that, in the above embodiments, the structures of the first position adjustment element, the second position adjustment element and the third position adjustment element may be the same or different, and the present invention is not limited to this, as the case may be. The structure of the position adjustment element will be described below by taking the first position adjustment element as an example.

It should be further noted that, since the laser generating element does not involve angle adjustment, in an embodiment of the present invention based on the above-mentioned embodiment, when the position adjusting element includes a first position adjusting element, a second position adjusting element and a third position adjusting element, optionally, the first position adjusting element and the third position adjusting element include a spatial position adjusting element and an angle adjusting element, and the second position adjusting element includes only the spatial position adjusting element and does not include the angle adjusting element.

In one embodiment of the present invention, as shown in fig. 7, the first position adjustment member includes: an angle adjusting element and a spatial position adjusting element 412 fixed on the angle adjusting element, the angle adjusting element comprises an angle adjusting knob 413 and a rotary bearing plate 411 for fixing the angle adjusting knob 413, the spatial position adjusting element 412 is fixed on the rotary bearing plate 411, wherein the spatial position adjusting element 412 is used for adjusting the position of the sensing probe element 200 in the direction X, Y, Z in the preset coordinate system, and the angle adjusting knob 413 is used for adjusting the angle of the sensing probe element 200 in the preset coordinate system. Optionally, the adjustment precision of the spatial position adjustment element 412 is in the nanometer level. Wherein the X-direction and the Y-direction are parallel to the surface of the diamond sample, i.e., parallel to the surface of the rotating load bearing plate, and the Z-direction is perpendicular to the surface of the diamond, i.e., perpendicular to the surface of the rotating load bearing plate.

In particular, and as further shown in fig. 7, in one embodiment of the present invention, the spatial position adjustment element 412 is an XYZ three-axis spatial displacement stage, and the angle adjustment element is rotatable along the X-axis and the Y-axis, optionally a coaxial two-dimensional rotary stage disposed below the XYZ three-axis spatial displacement device. Specifically, in an embodiment of the present invention, the angle adjusting knob 413 includes an X-axis angle adjusting knob 4131 and a Y-axis angle adjusting knob 4132, wherein the X-axis angle adjusting knob 4131 is configured to rotate the diamond sample along the X-axis, the Y-axis angle adjusting knob 4132 is configured to rotate the diamond sample around the Y-axis, and optionally, the angle adjusting knob 413 adjusts the angle of the sensing probe element 200 in the preset coordinate system by adjusting the angle of the rotating bearing plate 411 in the preset coordinate system, for example, the angle adjusting knob 413 drives the rotating bearing plate 411 to rotate around the X-axis and/or the Y-axis, so as to drive the spatial position adjusting element 412 fixedly connected to the rotating bearing plate 411 and the sensing probe element 200 to rotate correspondingly.

Optionally, the spatial position adjusting element includes a micro displacement stage and a nano displacement stage, in other embodiments of the present invention, the micro displacement stage is configured to adjust the position of the sensing probe element along the X-axis, the Y-axis, and the Z-axis, and the nano displacement stage is configured to adjust the position of the sensing probe element along the X-axis, the Y-axis, and the Z-axis, but the present invention is not limited thereto, and is specifically determined as the case may be.

It should be noted that, because the offset in the vertical direction is small during the operation of the measuring apparatus, in an embodiment of the present invention, the calibration of the thermal drift in the vertical direction is completed by adjusting the nano-displacement stage, so as to improve the calibration accuracy. Specifically, the position adjusting element is controlled to move in the vertical direction of the sensing probe element so as to calibrate the thermal drift in the vertical direction, and the fluorescence counting sum of all NV color centers is read out through the fluorescence collecting element once the position adjusting element is controlled to move; and finally, moving the control position adjusting element to the position with the largest number of the fluorometers of all the NV color centers, repeating the process for a plurality of times until the number of the fluorometers of the NV color centers meets a second preset condition, and finishing the calibration of the thermal drift in the vertical direction, wherein the calibration comprises the following steps: controlling the nanometer displacement table to perform the movement of the sensing probe element in the Z direction so as to calibrate the thermal drift in the Z direction, and controlling the fluorescence collection element to read out the sum of the fluorescence counts of all NV color centers once the nanometer displacement table moves; and finally, moving the control nano displacement table to the position with the largest number of the fluorescence counts of all the NV color centers, repeating the process for a plurality of times until the fluorescence counts of the NV color centers meet a second preset condition, and finishing the calibration of the thermal drift in the Z direction.

Alternatively, on the basis of the above embodiments, in one embodiment of the present invention, the sensing probe is fixed to a mount connected to the spatial position adjustment element and is symmetrical about the X-axis and the Y-axis, so that the angle adjustment knob rotates the diamond sample about the X-axis and/or the Y-axis, and the color center in the diamond sample does not deviate from the visual field when the angle of the diamond sample is adjusted, thereby facilitating the observation of the color center in the diamond sample while the angle of the diamond sample is adjusted.

On the basis of any one of the above embodiments, in an embodiment of the present invention, the radius range of the uniform magnetic field in the preset magnetic field is 1 mm magnitude, the strength can reach 1000 gauss magnitude at most, and the uniformity can reach more than 95%; the radius range of the uniform microwave field in the preset microwave field is 100 microns, the uniformity can reach more than 80%, and the intensity is determined according to specific test requirements.

Specifically, in one embodiment of the present invention, as shown in fig. 8, the microwave magnetic field generating element includes a microwave source 511, a microwave beam splitter 512, a microwave switch structure 513, a microwave combiner 514, a microwave amplifier 515, a magnetic field generating element 516, and an impedance matching element 517. Wherein the microwave switch structure 513 comprises a first microwave switch and a second microwave switch. The magnetic field generating element 516 includes a first magnetic field generating element 5161 and a second magnetic field generating element 5162.

Optionally, in an embodiment of the present invention, the first magnetic field generating element 5161 is a coil or a magnet, so as to generate a predetermined magnetic field; it should be noted that, in the embodiment of the present invention, when the first magnetic field generating element 5161 is a coil, a symmetric coil, such as a helmholtz coil, is preferable, and when the first magnetic field generating element 5161 is a magnet, a large-volume magnet is preferable, so as to provide a uniform external magnetic field along the NV color axis of the diamond sample; the second magnetic field generating element 5162 is a uniform radiation structure to generate a predetermined microwave field.

When the device works, the uniform radiation structure is fixed on a mounting seat connected with the spatial position adjusting element, and the sensing probe element is fixed on the surface of the uniform radiation structure; the microwave source is used for generating a pulse signal for controlling NV color center quantum states; the microwave beam splitter is used for splitting the pulse signal output by the microwave source into a first pulse signal and a second pulse signal with the phase difference of 90 degrees; the first pulse signal is transmitted to the microwave combiner through the first microwave switch, and the second pulse signal is transmitted to the microwave combiner through the second microwave switch, wherein the first microwave switch is used for controlling the length of the first pulse signal, and the second microwave switch is used for controlling the length of the second pulse signal; the microwave combiner combines the pulse signals output by the first microwave switch and the second microwave switch into one path; the microwave amplifier amplifies the pulse signals output by the microwave combiner and then couples the amplified pulse signals into the uniform radiation structure to generate a uniform microwave field so as to synchronously operate the quantum states of the multiple NV color centers, and finally the microwave amplifier is prevented from being damaged through the impedance matching element. The first pulse signal and the second pulse signal respectively correspond to a pulse signal in an X direction and a pulse signal in a Y direction.

Specifically, in one embodiment of the present invention, as shown in fig. 9, the sensing probe element 200 is fixed to the surface of the uniform radiating structure 5162 by an adhesive. Optionally, the adhesive is an optical curing adhesive which is non-fluorescent within 635nm to 800nm, but the invention is not limited thereto, and in other embodiments of the invention, the diamond sample may be fixed on the surface of the uniform radiation structure by oil absorption or mechanical fixing, as the case may be.

As further shown in fig. 9, in an embodiment of the present invention, the uniform radiation structure 5162 includes a bottom plate 903, and wiring structures 901 and microwave traces 902 located on the bottom plate and between the wiring structures 901, wherein the sensing probe element 200 is fixed on the bottom plate 903, and the wiring structures are used to electrically connect other devices and the microwave traces 902 to form a microwave field; wherein, the uniform microwave field generated by the uniform radiation structure 5162 completely covers the region to be measured on the sensing probe element 200.

On the basis of the above embodiments, in an embodiment of the present invention, the microwave magnetic field generating element further includes a square wave pulse generator, and the square wave pulse generator is configured to control the operating states of the first microwave switch and the second microwave switch, where the operating states of the first microwave switch and the second microwave switch include on and off; however, the present invention is not limited to this, and in other embodiments of the present invention, the first microwave switch and the second microwave switch may also be controlled by an external square wave pulse generator, as the case may be.

Correspondingly, an embodiment of the present invention further provides a high-throughput single-molecule magnetic resonance measurement method, which is applied to the high-throughput single-molecule magnetic resonance measurement apparatus provided in any of the above embodiments, as shown in fig. 10, the measurement method includes:

adjusting the position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element, so that the color center plane of the diamond sample included by the sensing probe element is coincident with the multi-point excitation light plane and the optical path direction of the fluorescence signal of the diamond sample is vertical to the light sensing plane of the fluorescence collecting element;

controlling the microwave magnetic field generating element to generate a preset magnetic field and a preset microwave field, enabling the magnetic field direction of the preset magnetic field to coincide with the NV axis of the diamond sample, and controlling the quantum state of the NV color center in the diamond sample by using the preset microwave field;

It should be noted that, in an actual measurement process, the high-flux single-molecule magnetic resonance measurement apparatus inevitably has a situation that the NV color center deviates from the corresponding excitation light spot due to factors such as thermal drift or phase shift of the spatial light modulator, so that the fluorescence count of the NV color center is reduced, and the high-flux single-molecule magnetic resonance measurement apparatus does not meet experimental requirements. Therefore, on the basis of any one of the above embodiments, in an embodiment of the present invention, the measurement method further includes:

On the basis of the foregoing embodiment, in an embodiment of the present invention, the determining, under the third preset condition, whether the NV color center count collected by the fluorescence collecting element is less than a preset number includes at least one of the following steps:

based on the stability of the high-flux single-molecule magnetic resonance measuring device, judging whether the NV color center count collected by the fluorescence collecting element is less than a preset number at preset intervals in the process of at least one step of collecting measured data;

before the step of collecting the measurement data is executed at least once, judging whether the NV color center count collected by the fluorescence collecting element is smaller than a preset number;

and after the step of collecting the measurement data is performed at least once, judging whether the NV color center count collected by the fluorescence collecting element is less than a preset number.

It should be noted that, in other embodiments of the present invention, the third preset condition may further include other conditions, so that at other time points or under other conditions, it is determined whether the NV color center count acquired by the fluorescence collecting element is smaller than a preset number, so that the high-flux single-molecule magnetic resonance measurement apparatus meets the experimental requirements, and the accuracy of the experimental data is improved.

The following describes the measurement method by taking as an example the case where, during the step of acquiring measurement data at least once, it is determined whether the NV color center count acquired by the fluorescence collecting element is less than a preset number at every preset time. Specifically, as shown in fig. 11, the measurement method includes:

performing the step of collecting the measurement data at least once;

in the process of performing the step of acquiring measurement data at least once, determining whether the NV color center count acquired by the fluorescence collecting element is less than a preset number every preset time until the measurement of the diamond sample is completed, optionally, the preset time is the time taken for performing the step of acquiring measurement data once, that is, after performing the step of acquiring measurement data once each time, determining whether the NV color center count acquired by the fluorescence collecting element is less than the preset number, but the present invention is not limited thereto, and in other embodiments of the present invention, the preset time may also be the time taken for performing the step of acquiring measurement data twice or other times, as the case may be;

and if the fluorescence count of the NV color center acquired by the fluorescence collecting element is not less than the preset count, continuing to execute the step of acquiring the measured data. Optionally, on the basis of the foregoing embodiment, in an embodiment of the present invention, the preset count is 70% of an initial value of the fluorescence count of the NV color center, but the present invention is not limited to this, which is determined as the case may be.

On the basis of the above embodiment, in a specific embodiment of the present invention, the measurement method includes:

if the execution times of the collected measurement data reach preset times, the measurement of the diamond sample is finished, and the measurement is finished;

if the execution times of the collected measurement data do not reach the preset times and if the fluorescence count of the NV color center collected by the fluorescence collecting element is smaller than the preset count, adjusting the position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element until the fluorescence count of the NV color center collected by the fluorescence collecting element is not smaller than the preset count, so that the high-flux single-molecule magnetic resonance measurement device meets the experimental requirements;

and if the execution times of the collected measurement data does not reach the preset times and if the fluorescence count of the NV color center collected by the fluorescence collection element is not less than the preset count, indicating that the high-flux monomolecular magnetic resonance measurement device meets the experimental requirements, continuing to execute the step of collecting the measurement data.

On the basis of the foregoing embodiment, in an embodiment of the present invention, the number of times of performing the step of acquiring measurement data is greater than 1, so as to improve the signal-to-noise ratio of the measurement signal, but the present invention is not limited thereto, as the case may be.

Specifically, on the basis of the above-described embodiments, in one embodiment of the present invention, controlling the laser generating element to generate the multi-spot excitation light includes:

dividing the current visual field range into n areas (such as n equal-sized square areas) with the same shape and size, and generating n laser light spots by using a spatial light modulator, wherein each area has one or more laser light spots, and the relative positions of the light spots in the respective areas are the same; changing the phase of the spatial light modulator to enable the laser light spots in each area to simultaneously scan the respective area, marking and outputting when NV color centers are scanned in the scanning process, and recording the positions of the NV color centers to obtain the positions of the NV color centers in the current view range;

the position of each NV color center is input to a spatial light modulator, and the phase of the spatial light modulator is encoded to generate multi-spot excitation light matched with each NV color center.

In one embodiment of the present invention, the inputting of the position of each NV color center into the spatial light modulator, and the encoding of the phase of the spatial light modulator to generate the multi-spot excitation light matched with each NV color center comprises:

after obtaining the positions of all the NV color centers in the visual field range, inputting the image recorded with the positions of all the NV color centers into a spatial light modulator, wherein the spatial light modulator can generate a corresponding phase gray scale image through an algorithm, and can generate a dot matrix (namely multi-point exciting light) for simultaneously exciting multi-point exciting light of all the NV color centers after Fourier change.

On the basis of any one of the above embodiments, in an embodiment of the present invention, a method for adjusting coincidence of the NV color center plane and the multi-point excitation light plane includes:

and after the laser generating element is controlled to generate the multi-point exciting light, adjusting the angles of the diamond sample and the spatial light modulator, and simultaneously observing the fluorescence count of the NV color center, wherein when the fluorescence count of the NV color center reaches the maximum, the NV color center plane is coincided with the multi-point exciting light plane.

On the basis of any of the above embodiments, in an embodiment of the present invention, as shown in fig. 12, the measuring method uses a computer to control a square wave sequence generator 611 as a clock source, and simultaneously control an acousto-optic modulator in the laser generating element 100 to perform laser switching, a fluorescence detector in the fluorescence collecting element 300 to perform fluorescence collection, and a microwave switching structure in the microwave magnetic field generating element 500 to output a microwave pulse signal to control a quantum state of an NV color center, so that the three are combined at a certain time sequence, and a magnetic field signal 612 is measured through the NV color center, optionally, the acousto-optic modulator in the laser generating element 100, the fluorescence detector in the fluorescence collecting element 300, and the microwave switching structure in the microwave magnetic field generating element 500 are controlled at a time sequence according to XY-8 or CPMG sequence, so as to measure a magnetic field signal, and the detailed measuring method can be seen in Science 347, 1135, (2015), the present invention is not described in detail herein.

It should be noted that, the adjusting of the position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element is performed until the fluorescence count of the NV color center collected by the fluorescence collecting element is not less than the preset count, and this step is used to calibrate the phenomenon that the NV color center deviates from the corresponding excitation light spot due to the phase drift of the laser generating element and the thermal drift of the measuring device.

Specifically, in an embodiment of the present invention, the adjusting the position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element until the fluorescence count of the NV color center acquired by the fluorescence collecting element is not less than a preset count includes:

taking the position of the NV color center recorded by NV color center scanning as a center, changing the additional phase of the spatial light modulator, moving an excitation light point, scanning two mutually perpendicular directions in sequence, optionally, the total moving distance in each direction is about 1 micrometer, the step length of single movement is 10 nanometer magnitude, and recording the sum of fluorescence counts of the NV color center obtained on a fluorescence collection element after each movement;

on the basis of any one of the foregoing embodiments, in an embodiment of the present invention, the adjusting the position of at least one of the laser generating element, the sensing probe element and the fluorescence collecting element until the fluorescence count of NV color centers collected by the fluorescence collecting element is not less than a preset count includes:

controlling a first position adjusting element to move the sensing probe element in the vertical direction to calibrate thermal drift in the vertical direction, wherein the fluorescence counting sum of all NV color centers is read out by a fluorescence collecting element once the first position adjusting element moves;

and moving the first position adjusting element to the position where the number of the fluorometers of all the NV color centers is the maximum, repeating the process for a plurality of times until the number of the fluorometers of the NV color centers meets a second preset condition, and finishing the calibration of the thermal drift in the vertical direction.

In summary, the measurement device and the measurement method provided by the embodiment of the invention can simultaneously collect signals of all single NV color centers in a visual field, solve the problem of low magnetic resonance spectrum test efficiency caused by factors such as short shelf life of protein molecules and slow test rate, and overcome the defects of low spatial resolution and incapability of measuring single molecule signals.

In addition, in the embodiment of the invention, the fluorescence detector adopts an electronic coupling device, the device has the advantages of low noise and high sensitivity, and the NV color center is sensitive to the detection of magnetism, so that the measuring device in the invention also has the advantages of low noise and high sensitivity.

In addition, the NV color center property in the diamond sample is stable, so that the whole sensing probe element comprising the NV color center is stable, and the measuring device disclosed by the invention has the advantage of high stability.

In the description, each part is described in a progressive manner, each part is emphasized to be different from other parts, and the same and similar parts among the parts are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-throughput single-molecule magnetic resonance measurement apparatus, comprising:

2. The measurement device of claim 1, wherein all NV colour centers in the diamond sample are distributed over a distance of 20 nm from the surface of the diamond sample.

3. The measurement device of claim 1, wherein a distance between any two NV color centers in the plurality of NV color centers along a first direction perpendicular to the surface of the diamond is less than 10 nanometers, and a distance along a second direction parallel to the surface of the diamond is greater than an optical diffraction limit of the system.

4. The measurement device of claim 1, wherein the laser generating element comprises: the device comprises a laser, an optical isolator, a first polaroid, an acousto-optic modulator group, a beam expanding system, a spatial light modulator and a first lens system, wherein the laser is used for generating first exciting light; the optical isolator is used for blocking exciting light on one side of the optical isolator, which faces away from the laser, from entering the laser through reflection; the first polaroid is used for adjusting the polarization direction of the first exciting light to a first polarization direction; the acousto-optic modulator group is used for controlling the on-off of the first exciting light; the beam expanding system is used for amplifying the light spot of the first exciting light to form a first light spot, so that the first light spot covers the whole target surface of the spatial light modulator; the spatial light modulator is used for modulating the phase of the first exciting light to form second exciting light with a plurality of phases; the first lens system is used for generating the multi-point excitation light based on the second excitation light of a plurality of phases output by the spatial light modulator.

5. The measurement device according to claim 4, wherein the set of acousto-optic modulators comprises: a plurality of acousto-optic modulators to control switching of the first excitation light.

6. A measuring device according to claim 4, wherein the first lens system comprises: the first lens is used for converging the second excitation light with multiple phases, the light filtering structure is located on a focal plane of the first lens and used for blocking zero-order diffraction light in emergent light of the first lens and filtering out the zero-order diffraction light in the converged second excitation light to form third excitation light, the second lens is used for converting the third excitation light into parallel fourth excitation light to be emitted, the dichroic mirror is used for changing the transmission direction of the fourth excitation light to enable the fourth excitation light to enter the objective lens, and the objective lens is used for forming multi-point excitation light to be emitted based on the fourth excitation light.

7. A measuring device according to claim 4, wherein the method of determining the location of all NV colour centres in the diamond sample within the current field of view comprises:

8. The measurement device of claim 1, wherein the position adjustment element comprises at least one of a first position adjustment element for adjusting at least one of a position and an angle of the sensing probe element in a preset coordinate system, a second position adjustment element for adjusting at least one of a position and an angle of the laser generating element in the preset coordinate system, and a third position adjustment element for adjusting at least one of a position and an angle of the fluorescence collecting element in the preset coordinate system; wherein the first position adjustment element comprises: the angle adjusting element comprises an angle adjusting knob and a rotary bearing plate used for fixing the angle adjusting knob, and the spatial position adjusting element is fixed on the rotary bearing plate and used for adjusting the position of the sensing probe element in the preset coordinate system along the direction X, Y, Z, and the angle adjusting knob is used for adjusting the angle of the sensing probe element in the preset coordinate system.

9. A high-throughput single-molecule magnetic resonance measurement method, which is applied to the high-throughput single-molecule magnetic resonance measurement apparatus according to claims 1 to 8, and comprises:

10. The measurement method according to claim 9, characterized in that the measurement method further comprises:

11. The method of measuring of claim 10, wherein the adjusting the position of at least one of the laser generating element, the sensing probe element, and the fluorescence collecting element until the fluorescence count of NV color centers collected by the fluorescence collecting element is not less than a preset count comprises:

and/or the presence of a gas in the gas,