Method, device and system for acquiring ODMR spectral line resonance frequency based on wide-field imaging

Abstract

The present invention provides a method, device and system for acquiring the resonance frequency of an ODMR spectrum line based on wide-field imaging, wherein the acquisition method is to first acquire the mean ODMR spectrum line of a fluorescence image, perform smooth fitting on it, determine its resonance frequency as a reference frequency, and determine the extreme value type corresponding to the reference frequency. Then, the ODMR spectrum line of a single pixel point or block is acquired, and the candidate frequency corresponding to the same extreme value type is acquired from the spectrum line, and the candidate frequency whose deviation is within the threshold range is matched for each reference frequency one by one, and there is no identical candidate frequency in the candidate frequencies matched by every two adjacent reference frequencies; when there is one matched candidate frequency, this candidate frequency is used as the resonance frequency; when there are multiple matched candidate frequencies, the candidate frequency with the highest peak height is selected as the resonance frequency. The resonance frequency of each pixel point or block can be determined more quickly and accurately, and the resonance frequency can also be efficiently determined for the ODMR spectrum line containing noise peaks.

Description

Technical Field

[0001] The invention relates to quantum sensing, and in particular to a method, a device and a system for acquiring the resonance frequency of an ODMR spectrum line based on wide-field imaging. Background Art

[0002] The magnetic measurement technology based on solid-state spin color centers is an emerging quantum technology. It uses the characteristics of spin color centers to produce energy level splitting under the action of a magnetic field, and combines it with quantum manipulation and other means to achieve the measurement of weak magnetic fields. For example, nanoscale diamond NV color centers have the advantages of being able to work at room temperature, having a short startup time, being easier to miniaturize and integrate, and are used in weak magnetic field detection. In combination with microscopic imaging technology, ultra-high-resolution imaging can be achieved, further expanding its application scenarios. In addition, quantum sensing technology based on solid-state spin color centers can also be used to measure other physical quantities, such as temperature, current, stress, etc.

[0003] Quantum measurement technology based on solid-state spin color centers mostly uses ODMR (light detection magnetic resonance) technology, which mainly irradiates excitation light to the solid-state spin color center and radiates microwaves to the solid-state spin color center at the same time. By scanning the microwave frequency, the ODMR spectrum line in which the fluorescence signal intensity changes with the microwave frequency can be obtained. The magnetic field or temperature can be calculated using the resonance frequency in the spectrum line. By combining ODMR technology with imaging technology, wide-field imaging can be achieved to measure the magnetic field or temperature distribution. When performing wide-field imaging, it is necessary to fit and draw the ODMR spectrum line for each pixel point, and after drawing, it is necessary to find and determine the resonance frequency at the resonance peak. When the number of pixels is small or the ODMR spectrum line for each pixel point is basically the same, the determination of the resonance frequency can be completed by finding the extreme point or assisting manual recognition.

[0004] However, in the actual processing process, each frame of the image contains hundreds of pixels. Due to the influence of noise, some pixels will have non-resonant peaks in the ODMR spectrum. Only extreme value search will cause errors in finding non-resonant peaks. When detecting the same magnetic field, for example, due to the influence of noise, or the magnetic field distribution is not absolutely completely uniform, there are slight differences, which causes slight differences in the ODMR spectrum of each pixel or pixel block, and the resonance frequency is also different. If the mean value of a single frame image is used to replace all pixels, it cannot truly reflect the magnetic field distribution of each pixel. How to more quickly and accurately determine the resonance frequency on the ODMR spectrum corresponding to each pixel or block has become a problem that needs to be solved. Summary of the invention

[0005] In view of the shortcomings of the prior art described above, an object of the present invention is to provide a method, device and system for acquiring the resonance frequency of ODMR spectral lines based on wide-field imaging, so as to solve the problem of how to quickly and accurately determine the resonance frequency on the ODMR spectral line corresponding to each pixel point or block in wide-field imaging.

[0006] To achieve the above objectives and other related objectives, the present invention provides a method for acquiring the resonance frequency of an ODMR spectrum line based on wide-field imaging, the method comprising:

[0007] S1, obtaining the detection value of each pixel point according to the fluorescence image data of the solid spin color center at each microwave frequency point, wherein the detection value is a value characterizing the fluorescence intensity, performing mean processing on the detection values ​​of all pixel points at the same microwave frequency to obtain the detection mean of the corresponding microwave frequency, drawing the mean ODMR spectrum line with the microwave frequency and its corresponding detection mean as the horizontal and vertical coordinates, and performing smooth fitting on the mean ODMR spectrum line, determining the resonance frequency from the resonance peak in the fitted spectrum line, and taking it as the reference frequency; and determining the extreme value type of the resonance peak;

[0008] S2, using the microwave frequency and the detection value of each pixel point corresponding to it or the detection mean value of a block composed of multiple pixel points as the horizontal and vertical coordinates, plotting the ODMR spectrum line of each pixel point or block, and performing smooth fitting on the ODMR spectrum line; then executing step S3 on the ODMR spectrum line after smooth fitting of one pixel point or one block;

[0009] S3, obtaining all extreme value points of the same extreme value type as that determined in step S1 in the smooth fitting spectrum, and determining whether the number of extreme value points is not less than n, where n is an integer and is the number of reference frequencies; if so, obtaining the microwave frequency corresponding to each extreme value point, taking it as a candidate frequency, and executing step S4; if not, executing step S5;

[0010] S4, matching candidate frequencies whose deviations are within a threshold range for each reference frequency one by one, and there is no identical candidate frequency among the candidate frequencies matched by every two adjacent reference frequencies; when there is only one matching candidate frequency, using this candidate frequency as the resonance frequency; when there are multiple matching candidate frequencies, selecting the candidate frequency with the highest peak height as the resonance frequency; and then executing step S6;

[0011] S5, taking the reference frequency as the resonance frequency of the pixel point or block; and then executing step S6;

[0012] S6, determining whether there are pixels or blocks with undetermined resonance frequencies, if so, selecting one of the pixels or blocks with undetermined resonance frequencies, and executing step S3 for the smoothed ODMR spectrum; if not, ending.

[0013] Further, step S4 includes the following steps:

[0014] S41, matching each reference frequency with a candidate frequency whose deviation is within a threshold range one by one to form a corresponding matching group, and obtaining the number of matched candidate frequencies in each matching group as the number of matches; executing step S42;

[0015] S42, determine whether there is a matching group with a matching number of 0, if yes, execute step S45, if not, execute step S43;

[0016] S43, determining whether there are two adjacent reference frequency matching groups with the same candidate frequency, if so, retaining the same candidate frequency only in the matching group corresponding to the reference frequency with the smallest deviation therefrom, and executing step S42 for each newly formed matching group, if not, executing step S44 for all matching groups;

[0017] S44, when there is only one matching candidate frequency, use the candidate frequency as the resonance frequency; when there are multiple matching candidate frequencies, select the candidate frequency with the highest peak height as the resonance frequency;

[0018] S45, determining whether the threshold reaches a preset maximum threshold range, if not, increasing the threshold range and executing step S41, if yes, executing step S5.

[0019] Furthermore, the detection value is a grayscale value of the image.

[0020] Furthermore, the solid-state spin color center is one of a diamond nitrogen vacancy color center, a diamond germanium vacancy color center, a diamond silicon vacancy color center, a silicon carbide divacancy color center, a silicon carbide silicon vacancy color center, and a hexagonal boron nitride boron vacancy color center.

[0021] To achieve the above-mentioned purpose and other related purposes, the present invention provides a measurement method based on solid-state spin color centers, comprising: in a test environment, irradiating excitation light and radiating microwaves to the solid-state spin color centers, scanning the microwave frequency, collecting and imaging the fluorescence generated by the solid-state spin color centers, and obtaining fluorescence image data;

[0022] According to the fluorescence image data, the resonance frequency of each pixel point or block is obtained by using any of the above methods for obtaining the resonance frequency of the ODMR spectrum line based on wide-field imaging;

[0023] The magnetic field intensity at each pixel point or block is calculated according to the resonance frequency of each pixel point or block, or the temperature value at each pixel point or block is calculated.

[0024] Furthermore, a bias magnetic field is applied to the solid-state spin color center.

[0025] To achieve the above-mentioned and other related purposes, the present invention provides an acquisition device for ODMR spectral line resonance frequency for wide-field imaging, comprising:

[0026] one or more processors;

[0027] A memory for storing one or more programs;

[0028] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for acquiring the resonance frequency of the ODMR spectrum line based on wide-field imaging as described above.

[0029] To achieve the above-mentioned purpose and other related purposes, the present invention provides a computer-readable storage medium: a computer program is stored on the storage medium; when the computer program is executed by a processor, the method for acquiring the resonance frequency of the ODMR spectral line based on wide-field imaging as described above is implemented.

[0030] To achieve the above-mentioned and other related purposes, the present invention provides a wide-field imaging system based on solid-state spin color centers, comprising: a probe, an optical detection unit, a microwave unit, and an acquisition device for the resonance frequency of the ODMR spectrum line for wide-field imaging as described above, wherein the probe comprises a solid-state spin color center;

[0031] The microwave unit is used to radiate microwaves to the probe

[0032] The optical detection unit is used to irradiate the probe with excitation light, collect and image the fluorescence generated by the probe, obtain fluorescence image data, and transmit it to the acquisition device;

[0033] The acquisition device acquires the resonance frequency of each pixel point or block according to the fluorescence image data.

[0034] Furthermore, it also includes a bias magnetic field unit for applying a bias magnetic field to the probe.

[0035] As described above, the method, device and system for acquiring the resonance frequency of the ODMR spectrum line based on wide-field imaging of the present invention have the following beneficial effects: first, the mean ODMR spectrum line of the image is acquired, smoothed and fitted, and its resonance frequency is determined as the reference frequency for the subsequent determination of the resonance frequency of a single pixel point or block. Then, the ODMR spectrum line of a single pixel point or block is acquired, and the candidate frequency corresponding to the extreme point is obtained from the spectrum line, and the candidate frequency whose deviation is within the threshold range is matched for each reference frequency one by one, and there is no identical candidate frequency in the candidate frequencies matched by every two adjacent reference frequencies; when there is one matched candidate frequency, this candidate frequency is used as the resonance frequency; when there are multiple matched candidate frequencies, the candidate frequency with the highest peak height is selected as the resonance frequency. The resonance frequency of each pixel point or block can be determined more quickly and accurately, and the resonance frequency can also be efficiently determined for the ODMR spectrum line containing noise peaks. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Shown is a schematic flow chart of a method for obtaining the resonance frequency of an ODMR spectrum line of the present invention;

[0037] Figure 2 It is a schematic flow chart of a method for obtaining a resonance frequency by matching within a threshold range according to the present invention;

[0038] Figure 3 Shown is a schematic diagram of the mean ODMR spectrum of the present invention;

[0039] Figure 4 The present invention is shown Figure 3 Schematic diagram of block ODMR spectrum lines with one-to-one matching of resonance peaks in;

[0040] Figure 5 Shown is a schematic diagram of a block ODMR spectrum line containing a noise peak according to the present invention;

[0041] Figure 6 Shown is a schematic structural diagram of a wide-field imaging system based on a solid-state spin color center according to the present invention;

[0042] Figure 7 Shown is an exemplary diagram of a wide-field imaging system based on solid-state spin color centers according to the present invention.

[0043] Component number explanation: 1—probe; 2—optical detection unit; 21—excitation light source; 22—beam expander; 23—objective lens; 24—filter; 25—imaging camera; 26—dichroic plate; 3—microwave unit; 31—microwave source; 32—microwave amplifier; 33—microwave circulator; 34—microwave antenna; 4—magnet; 5—pulse control unit; 100—equipment for acquiring the resonance frequency of the ODMR spectral line for wide-field imaging. DETAILED DESCRIPTION

[0044] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0045] It should be noted that the illustrations provided in the following embodiments are only used to illustrate the basic concept of the present invention in a schematic manner, and thus the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0046] Embodiment 1: Figure 1 As shown, this embodiment provides a method for acquiring the resonance frequency of an ODMR spectrum line based on wide-field imaging, comprising:

[0047] S1, according to the fluorescence image data of the solid spin color center at each microwave frequency point, obtain the detection value of each pixel point, the detection value is a value characterizing the fluorescence intensity, the detection values ​​of all pixel points under the same microwave frequency are averaged to obtain the detection mean of the corresponding microwave frequency, the microwave frequency and its corresponding detection mean are used as the horizontal and vertical coordinates, the mean ODMR spectrum line is drawn, and the mean ODMR spectrum line is smoothly fitted, and the resonance frequency is determined from the resonance peak in the fitted spectrum line, which is used as the reference frequency; and the extreme value type of the resonance peak is determined;

[0048] S2, using the microwave frequency and the detection value of each pixel point corresponding to it or the detection mean value of a block composed of multiple pixel points as the horizontal and vertical coordinates, plotting the ODMR spectrum line of each pixel point or block, and performing smooth fitting on the ODMR spectrum line; then executing step S3 on the ODMR spectrum line after smooth fitting of one pixel point or one block;

[0049] S3, obtaining all extreme value points of the same extreme value type as that determined in step S1 in the smooth fitting spectrum, and determining whether the number of extreme value points is not less than n, where n is an integer and is the number of reference frequencies; if so, obtaining the microwave frequency corresponding to each extreme value point, taking it as a candidate frequency, and executing step S4; if not, executing step S5;

[0050] S4, matching candidate frequencies whose deviations are within a threshold range for each reference frequency one by one, and there is no identical candidate frequency among the candidate frequencies matched by every two adjacent reference frequencies; when there is only one matching candidate frequency, using this candidate frequency as the resonance frequency; when there are multiple matching candidate frequencies, selecting the candidate frequency with the highest peak height as the resonance frequency; and then executing step S6;

[0051] S5, taking the reference frequency as the resonance frequency of the pixel point or block; and then executing step S6;

[0052] S6, determining whether there are pixels or blocks with undetermined resonance frequencies, if so, selecting one of the pixels or blocks with undetermined resonance frequencies, and executing step S3 for the smoothed ODMR spectrum; if not, ending.

[0053] In this embodiment, the fluorescence image data is obtained by imaging the fluorescence of the solid spin color center, and at least includes the detection value at each pixel at each frequency, and the detection value is represented by the gray value of the image. In step S1, the mean ODMR spectrum of the image is first obtained, and smoothed fitting is performed on it, such as Figure 3 The smooth curve shown in FIG. 1 is used to determine the resonance frequency from the resonance peak, which is used as a reference for determining the resonance frequency of a subsequent single pixel or block. The resonance peak in the mean ODMR spectrum can be determined by extreme value search combined with manual judgment. The types of extreme values ​​include maximum and minimum. The drawn ODMR spectrum can be as follows: Figure 3 As shown, the resonance frequency is the horizontal coordinate of the resonance peak, and the extreme value type is the minimum value; due to phase or data processing reasons, there may also be Figure 3 The resonance peak is symmetrical up and down. At this time, the resonance peak is the maximum value. Determine the extreme value type in this step to facilitate the determination of the same type of extreme value in step S3. In step S2, the ODMR spectrum is drawn and smoothed for the single pixel point or block. In step S3, when the extreme value point is less than n, it means that there is a large error in the data of this pixel point or block. The reference frequency is used as the resonance frequency of this pixel point or block. For color centers with high and uniform concentrations, the probability of this situation is small. Generally, the number of resonance peaks of pixels or blocks is consistent with the average of the entire image. See Figure 3-Figure 4 The ODMR spectrum of the diamond nitrogen vacancy color center shown in the figure exemplifies the case where there are 8 resonance peaks. Depending on the angle between the magnetic field and the axis of the color center, the number of resonance peaks can be 2, 4, 6, or 8, which are the possible values ​​of n.

[0054] Since the reference frequency has made a preliminary estimate of the to-be-measured value in the environment, such as magnetic field, temperature, etc., by matching different candidate frequencies for each reference frequency based on the threshold range in step S4, such as Figure 4As shown, it is the ODMR spectrum of a multi-pixel block composed of multiple pixels. The resonance frequency in the figure is relative to Figure 3 There is an offset in the reference frequency, within a threshold range Δf, for example (-5, +5), in units of MHz, to achieve a one-to-one match.

[0055] When there is a noise peak, the noise peak will appear in a one-to-many match, because if the one-to-one match is a noise peak, the deviation between the noise peak and the corresponding reference frequency needs to be small enough, and the threshold range must also be small enough, which may make other reference frequencies unable to match the candidate frequency. Therefore, the noise peak will appear in a one-to-many match. For a one-to-many match, since the peak height of the noise peak is generally lower than the peak height of the resonance peak when the measurement signal-to-noise ratio is constant, the candidate frequency with the highest peak height is selected as the resonance frequency. In this way, the interference of the noise peak can be reduced and the accuracy of the resonance frequency determination can be improved.

[0056] like Figure 5 As shown, the resonance frequency of this multi-pixel block is relatively Figure 3 The reference frequency is offset, and noise peaks f4'', f5'' and f5''' appear. By setting and adjusting the threshold range Δf, for example, when adjusted to (-15, +15), the unit is MHz, and the resonance frequency corresponding to the reference frequency within the threshold range Δf is obtained, wherein the reference frequencies f1-f4, f6-f8 correspond to the frequencies f1'-f4', f6'-f8' one-to-one, so f1'-f4', f6'-f8' are determined as the resonance frequencies, and the reference frequency f5 corresponds to f5' and f5''', and f5' with the highest peak height is determined as the resonance frequency. Therefore, the method in this embodiment can quickly and effectively handle the problem of determining the resonance frequencies of hundreds or thousands, or even more, pixels or blocks.

[0057] In this embodiment, the solid-state spin color center can be one of a diamond nitrogen vacancy color center, a diamond germanium vacancy color center, a diamond silicon vacancy color center, a silicon carbide divacancy color center, a silicon carbide silicon vacancy color center, and a hexagonal boron nitride boron vacancy color center, all of which are detected based on the photoluminescence effect of the color center.

[0058] The threshold range in this embodiment can be determined as an initial range based on experience from multiple measurements, and can be adjusted and determined in real-time measurements. The threshold range includes a case where it is a fixed value.

[0059] The threshold range can also be determined by experimental means, specifically, by applying a magnetic field of known distribution to the solid spin color center and scanning the microwave frequency to obtain the resonance frequency of the detection mean and the resonance frequency of multiple pixels, and then compare the deviation of the resonance frequency of each pixel with the corresponding resonance frequency of the mean, and obtain the minimum and maximum threshold ranges from the fluctuation of the deviation. It is also possible to change multiple magnetic fields to obtain more floating ranges, and then select a suitable threshold range. Of course, the threshold range can also be determined based on experiments combined with empirical values.

[0060] Since the solid-state spin color centers and microwave distribution used in each measurement are the same, after the minimum and maximum values ​​of the threshold range are determined in the early stage, they can be used as parameters repeatedly in the measurement process, greatly improving the measurement efficiency.

[0061] In this embodiment, the smooth fitting method for the ODMR spectrum line can adopt the moving average method, the loess method, the linear regression method, etc. The number of smooth fitting can be once or multiple times. The smaller noise peak can be removed by smooth fitting, and the accuracy of the resonance peak determination can be improved. For the search method of the extreme point, the numerical comparison method, the extreme value search function in the tool such as MATLAB can be used for search, the curve fitting derivation method, etc. In step S1, since there is only one mean ODMR spectrum line, the resonance frequency can be determined by the automatic search of the program combined with manual correction to improve the accuracy of the resonance frequency determination.

[0062] Embodiment 2: Based on Embodiment 1, Figure 2 As shown, step S4 includes the following steps:

[0063] S41, matching each reference frequency with a candidate frequency whose deviation is within a threshold range one by one to form a corresponding matching group, and obtaining the number of matched candidate frequencies in each matching group as the number of matches; executing step S42;

[0064] S42, determine whether there is a matching group with a matching number of 0, if yes, execute step S45, if not, execute step S43;

[0065] S43, determining whether there are two adjacent reference frequency matching groups with the same candidate frequency, if so, retaining the same candidate frequency only in the matching group corresponding to the reference frequency with the smallest deviation therefrom, and executing step S42 for each newly formed matching group, if not, executing step S44 for all matching groups;

[0066] S44, when there is only one matching candidate frequency, use the candidate frequency as the resonance frequency; when there are multiple matching candidate frequencies, select the candidate frequency with the highest peak height as the resonance frequency;

[0067] S45, determining whether the threshold reaches a preset maximum threshold range, if not, increasing the threshold range and executing step S41, if yes, executing step S5.

[0068] In step S42, if there is a matching group with a matching number of 0, it means that the set threshold range is too small, and the threshold range needs to be increased to match the candidate frequency corresponding to the reference frequency. The size of each adjustment of the threshold range is set in advance.

[0069] In step S43, if there are two adjacent reference frequencies with the same candidate frequency in the matching group, it means that the threshold range set may be too large for the resonance frequency corresponding to the two reference frequencies. This same candidate frequency is only retained in the matching group corresponding to the reference frequency with the smallest deviation to narrow the deviation range of the matching; there may also be interference from noise peaks, which can be included in the matching group with the smallest deviation and then excluded in the subsequent step S44. To avoid the noise peak being retained in one matching group and the number of the other matching group becoming 0, this may be because the threshold range is too small for the resonance frequency corresponding to the reference frequency, resulting in the corresponding resonance peak not being matched in the matching group that becomes 0, and the judgment of the number of matches in step S42 continues.

[0070] In step S43, if the threshold range is too large, Figure 5 As shown, if the threshold range Δf is set to (-27, +27), for the reference frequency f3, two resonant frequencies f3' and f4' may be matched, and the resonant frequency f4' is matched to the reference frequency f4. Therefore, in step S43, since the deviation between f4' and the reference frequency f4 is the smallest, f4' is only retained in the matching group corresponding to the reference frequency f4, so that the reference frequency f3 is matched to the resonant frequency f3'.

[0071] When setting the initial threshold, a smaller range is preferred to facilitate determining a reasonable threshold by gradually increasing the threshold. In this embodiment, by setting step S43, while solving the noise peak interference, it can also solve the problem of a large threshold range caused by too large a step increase in the threshold.

[0072] It can be seen that within the measurable ODMR spectrum line variation range, the resonance frequency acquisition method of this embodiment can quickly and accurately solve the problem of acquiring the ODMR resonance frequency of a large number of single-pixel or multi-pixel blocks with noise peaks.

[0073] Embodiment 3: This embodiment provides a measurement method based on solid-state spin color centers, comprising: in a test environment, irradiating the solid-state spin color center with excitation light and radiating microwaves, scanning the microwave frequency, collecting and imaging the fluorescence generated by the solid-state spin color center, and obtaining fluorescence image data;

[0074] According to the fluorescence image data, the resonance frequency of each pixel point or block is obtained by using the method for obtaining the resonance frequency of the ODMR spectrum line based on wide-field imaging in the first or second embodiment;

[0075] The magnetic field intensity at each pixel point or block is calculated according to the resonance frequency of each pixel point or block, or the temperature value at each pixel point or block is calculated.

[0076] Taking the diamond nitrogen vacancy color center as an example, when the color center axis is adjusted to be parallel to the magnetic field direction, To calculate the magnetic field on the axis of this color center ,in is the gyromagnetic ratio, , are two resonant frequencies on the same axis. The temperature is calculated based on the resonant frequency of the ODMR spectrum. The specific formula is: as well as , Zero field splitting, =2.87GHz, =-74KHz / K, is the temperature to be measured, It is room temperature.

[0077] A bias magnetic field can also be applied to the solid spin color center. In the initial state, that is, when only the bias magnetic field is applied, the resonance peak of the color center is degenerate. For example, a bias magnetic field is applied to the diamond NV color center, so that the ODMR presents 8 peaks. After the magnetic field to be measured is applied, the change of the magnetic field will cause the resonance frequency of the 8 peaks to move respectively. By detecting these changes, the vector change of the magnetic field to be measured can be inferred. In addition, the bias magnetic field can also be used to adjust the detection frequency band to improve the sensitivity of weak magnetic detection.

[0078] For other solid-state spin color centers, they can be calculated based on the corresponding relationship between the magnetic field or temperature and their ODMR spectral lines, which will not be elaborated here.

[0079] Embodiment 4: This embodiment provides an ODMR spectrum line resonance frequency acquisition device 100 for wide-field imaging, including:

[0080] one or more processors;

[0081] A memory for storing one or more programs;

[0082] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for acquiring the ODMR spectral line resonance frequency based on wide-field imaging as described in the first or second embodiment.

[0083] The processor may be a central processing unit (CPU), or may be a special integrated circuit (SSIC), or may be configured to implement one or more integrated circuits of the embodiments of the present disclosure.

[0084] The memory may include, for example, a system memory, a fixed non-volatile storage medium, etc. The system memory may store, for example, an operating system, an application program, a boot loader, a database, and other programs.

[0085] This embodiment further provides a computer-readable storage medium, on which a computer program is stored; when the computer program is executed by a processor, the method for acquiring the resonance frequency of the ODMR spectral line based on wide-field imaging as in the first or second embodiment is implemented.

[0086] Among them, computer-readable storage media include but are not limited to various media that can store program codes such as USB flash drives, mobile hard disks, read-only memories ROM, ReSd-Only Memory, random access memories RSM, RSndom Sccess Memory, disks or optical disks, or any suitable combination of the above contents.

[0087] Embodiment 5: This embodiment provides a wide-field imaging system based on solid-state spin color centers, such as Figure 6 As shown, it includes: a probe 1, an optical detection unit 2, a microwave unit 3, and an acquisition device 100 for the resonance frequency of the ODMR spectrum line for wide-field imaging in the fourth embodiment, wherein the probe 1 includes a solid spin color center;

[0088] The microwave unit 3 is used to radiate microwaves to the probe 1;

[0089] The optical detection unit 2 is used to irradiate the excitation light to the probe 1, collect and image the fluorescence generated by the probe 1, obtain fluorescence image data, and transmit it to the acquisition device 100;

[0090] The acquisition device 100 acquires the resonance frequency of each pixel or block according to the fluorescence image data;

[0091] The solid spin color center can be as described in Example 1. For the excitation light, for example, diamond nitrogen vacancy color center and hexagonal boron nitride boron vacancy color center, 532nm green excitation light is generally used; silicon carbide carbon-silicon divacancy color center uses 900-940nm excitation light, and other color centers can be excited by corresponding excitation light.

[0092] In this embodiment, the probe 1 is composed of diamond nitrogen vacancy color centers and adopts a sheet-like diamond structure to form a large-range wide-field imaging. Figure 7As an example, the optical detection unit 2 includes an illumination device and an imaging device. The illumination device irradiates the excitation light to the probe, and the imaging device receives the fluorescence generated by the probe 1 to collect and image, and obtains fluorescence image data. The fluorescence image data at least includes the detection value at each pixel point at each frequency, and the detection value is represented by a grayscale value. The illumination device includes an excitation light source 21, and may also include one or more optical elements for expanding and / or focusing a collimated light beam. For example, the beam expander 22 shown in the figure is used to expand and collimate light with a smaller beam diameter to meet the requirements for the spot size. A filter may also be included to filter the excitation light to obtain a wavelength that meets the irradiation requirements. The excitation light source 21 may be a light source in the form of a laser or LED. The imaging device includes an objective lens 23, a filter 24, and an imaging camera 25. The fluorescence is collected by the objective lens 23, transmitted to the filter 24 for filtering, and then entered into the imaging camera 25 for imaging and converted into fluorescence image data. The imaging camera 25 may be a CCD or CMOS type camera.

[0093] The optical detection unit 2 may also include at least one optical device for guiding the excitation light generated by the illumination device to the probe 1, and guiding the fluorescence generated by the probe 1 to the imaging device. For example, as shown in the figure, a dichroic film 26 is used to reflect the excitation light to the probe 1, and the fluorescence generated by the probe 1 is transmitted through the dichroic film 26 and then transmitted to the filter 24 and the imaging camera 25.

[0094] The optical detection unit 2 may also adopt other structural forms, which will not be described in detail here.

[0095] The microwave unit 3 is exemplified as Figure 7 As shown, it includes a microwave source 31, a microwave amplifier 32, a microwave circulator 33, and a microwave antenna 34. Microwaves are radiated to the probe through the microwave antenna 34. The microwave antenna 34 uses a coplanar waveguide, and the sheet diamond is located in the center hole of the coplanar waveguide or below the center hole. The sample to be tested can be placed below the microwave antenna.

[0096] It also includes a bias magnetic field unit for applying a bias magnetic field to the probe to adjust the generated resonance peak or adjust the detection frequency band to improve the sensitivity of weak magnetic field detection. The bias magnetic field unit includes a magnet 4, which can be an electromagnet or a permanent magnet.

[0097] In order to achieve synchronization between radiated microwaves and camera exposure and storage, a pulse control unit 5 is also provided for transmitting a pulse signal to the microwave source 31 and the imaging camera 25 to trigger the switching of the microwave frequency and the start of camera exposure. The pulse signal may be a TTL signal.

[0098] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for acquiring the resonance frequency of ODMR spectral lines based on wide-field imaging, characterized in that: The method comprises: S1, obtaining the detection value of each pixel point according to the fluorescence image data of the solid spin color center at each microwave frequency point, wherein the detection value is a value characterizing the fluorescence intensity, performing mean processing on the detection values ​​of all pixel points at the same microwave frequency to obtain the detection mean of the corresponding microwave frequency, drawing the mean ODMR spectrum line with the microwave frequency and its corresponding detection mean as the horizontal and vertical coordinates, and performing smooth fitting on the mean ODMR spectrum line, determining the resonance frequency from the resonance peak in the fitted spectrum line, and taking it as the reference frequency; and determining the extreme value type of the resonance peak; S2, using the microwave frequency and the detection value of each pixel point corresponding to it or the detection mean value of a block composed of multiple pixel points as the horizontal and vertical coordinates, plotting the ODMR spectrum line of each pixel point or block, and performing smooth fitting on the ODMR spectrum line; then executing step S3 on the ODMR spectrum line after smooth fitting of one pixel point or one block; S3, obtaining all extreme value points of the same extreme value type as that determined in step S1 in the smooth fitting spectrum, and determining whether the number of extreme value points is not less than n, where n is an integer and is the number of reference frequencies; if so, obtaining the microwave frequency corresponding to each extreme value point, taking it as a candidate frequency, and executing step S4; if not, executing step S5; S4, matching candidate frequencies whose deviations are within a threshold range for each reference frequency one by one, and there is no identical candidate frequency among the candidate frequencies matched by every two adjacent reference frequencies; when there is only one matching candidate frequency, using this candidate frequency as the resonance frequency; when there are multiple matching candidate frequencies, selecting the candidate frequency with the highest peak height as the resonance frequency; and then executing step S6; S5, taking the reference frequency as the resonance frequency of the pixel point or block; and then executing step S6; S6, determining whether there are pixels or blocks with undetermined resonance frequencies, if so, selecting one of the pixels or blocks with undetermined resonance frequencies, and executing step S3 for the smoothed ODMR spectrum; if not, ending.

2. The method for obtaining the ODMR spectral line resonance frequency according to claim 1, characterized in that: Step S4 includes the following steps: S41, matching each reference frequency with a candidate frequency whose deviation is within a threshold range one by one to form a corresponding matching group, and obtaining the number of matched candidate frequencies in each matching group as the number of matches; Execute step S42; S42, determine whether there is a matching group with a matching number of 0, if yes, execute step S45, if not, execute step S43; S43, determining whether there are two adjacent reference frequency matching groups with the same candidate frequency, if so, retaining the same candidate frequency only in the matching group corresponding to the reference frequency with the smallest deviation therefrom, and executing step S42 for each newly formed matching group, if not, executing step S44 for all matching groups; S44, when there is only one matching candidate frequency, use the candidate frequency as the resonance frequency; when there are multiple matching candidate frequencies, select the candidate frequency with the highest peak height as the resonance frequency; S45, determining whether the threshold reaches a preset maximum threshold range, if not, increasing the threshold range and executing step S41, if yes, executing step S5.

3. The method for obtaining the resonance frequency of the ODMR spectrum line according to claim 1, characterized in that: The detection value is the gray value of the image.

4. The method for obtaining the ODMR line resonance frequency according to any one of claims 1 to 3, characterized in that: The solid-state spin color center is one of a diamond nitrogen vacancy color center, a diamond germanium vacancy color center, a diamond silicon vacancy color center, a silicon carbide divacancy color center, a silicon carbide silicon vacancy color center, and a hexagonal boron nitride boron vacancy color center.

5. A measurement method based on solid-state spin color centers, characterized in that: The method comprises: in a test environment, irradiating the solid spin color center with excitation light and radiating microwaves, scanning the microwave frequency, collecting and imaging the fluorescence generated by the solid spin color center, and obtaining fluorescence image data; According to the fluorescence image data, the resonance frequency of each pixel point or block is obtained by using the method for obtaining the resonance frequency of the ODMR spectrum line based on wide-field imaging as described in any one of claims 1 to 4; The magnetic field intensity at each pixel point or block is calculated according to the resonance frequency of each pixel point or block, or the temperature value at each pixel point or block is calculated.

6. The measurement method based on solid-state spin color centers according to claim 5, characterized in that: A bias magnetic field is also applied to the solid-state spin color center.

7. An acquisition device (100) for ODMR spectral line resonance frequency for wide-field imaging, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for acquiring the resonance frequency of the ODMR spectrum line based on wide-field imaging according to any one of claims 1 to 4.

8. A computer-readable storage medium, characterized in that: The storage medium stores a computer program; when the computer program is executed by the processor, the method for acquiring the ODMR spectral line resonance frequency based on wide-field imaging according to any one of claims 1 to 4 is implemented.

9. A wide-field imaging system based on solid-state spin color centers, characterized in that: The system comprises: a probe (1), an optical detection unit (2), a microwave unit (3), and an acquisition device (100) for the resonance frequency of ODMR spectral lines for wide-field imaging as claimed in claim 7, wherein the probe (1) comprises a solid-state spin color center; The microwave unit (3) is used to radiate microwaves toward the probe (1); The optical detection unit (2) is used to irradiate the probe (1) with excitation light, collect and image the fluorescence generated by the probe (1), obtain fluorescence image data, and transmit the data to the acquisition device (100); The acquisition device (100) acquires the resonance frequency of each pixel point or block according to the fluorescence image data.

10. The wide-field imaging system based on solid-state spin color centers according to claim 9, characterized in that: It also includes a bias magnetic field unit, which is used to apply a bias magnetic field to the probe (1).

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