Vector magnetic field detection system based on diamond NV color center

Abstract

The invention provides a vector magnetic field detection system based on a diamond NV color center, and relates to the technical field of magnetic field detection. The system comprises a diamond NV color center heald, a laser generation device, two fluorescence detection assemblies, two microwave antennas, a differential phase locking assembly and a bias magnetic field generation device, the diamond NV color center heddle is provided with two interval grooves which are arranged at an interval, and the two interval grooves divide the diamond NV color center heddle into a first area, a second area and a third area which are arranged in sequence; the depth of the spacing grooves is smaller than the thickness of the diamond NV color center system heald, so that three areas on the upper layer of the diamond NV color center system heald are isolated, and three areas on the lower layer of the diamond NV color center system heald are communicated. Functional division is carried out on a single diamond block, and temperature drift of a bias magnetic field and common-mode noise of a stray magnetic field are inhibited by utilizing the difference of far and near magnetic field intensities sensed by different detection areas; and the two detection areas are on the same piece, so that the consistency is good, and the detection precision is improved.

Description

Technical Field

[0001] This invention relates to the field of magnetic field detection technology, and in particular to a vector magnetic field detection system based on diamond NV color centers. Background Technology

[0002] Diamond vector magnetometer probes utilize nitrogen-vacancy (NV) color center quantum sensing technology in diamond, offering significant advantages such as ultra-high sensitivity, nanometer-level spatial resolution, and the ability to operate at room temperature and pressure. Their applications are extremely broad, comprehensively covering multiple important fields including scientific research, industry, medicine, and geology.

[0003] In existing technologies, diamond vector magnetometer probes typically consist of a single diamond material, a photodetector, and a microwave antenna. When measuring vector magnetic fields, a bias magnetic field needs to be applied to split the four NV axes into eight peaks. The strength of the bias magnetic field drifts with temperature, and this temperature drift, along with stray magnetic fields, significantly affects the detection accuracy of the diamond vector magnetometer probe. Summary of the Invention

[0004] This invention provides a vector magnetic field detection system based on diamond NV color centers to solve the problem of inaccurate detection by diamond vector magnetometer probes in the prior art due to the influence of temperature drift of the bias magnetic field and stray magnetic field.

[0005] In a first aspect, embodiments of the present invention provide a vector magnetic field detection system based on diamond NV color centers. Includes: diamond NV color center ensemble, laser generator, two fluorescence detection components, two microwave antennas, differential phase-locked loop assembly and bias magnetic field generator; The diamond NV color center helium has two spacer slots arranged at intervals, which divide the diamond NV color center helium into a first region, a second region, and a third region arranged sequentially. The depth of the spacer slots is less than the thickness of the diamond NV color center helium, so that the first, second, and third regions of the upper layer of the diamond NV color center helium are isolated, while the first, second, and third regions of the lower layer of the diamond NV color center helium are connected. Two microwave antennas are respectively mounted on the upper surface of the first region and the upper surface of the third region to receive modulation signals; The laser generator is used to generate two laser beams, which are respectively irradiated in the first region and the third region; A bias magnetic field generating device is used to generate a bias magnetic field; Two fluorescence detection components are used to detect the fluorescence in the first region and the fluorescence in the third region, respectively, and send the results to the differential phase-locked loop component.

[0006] Optionally, the diamond NV color center heddle sheet is a rectangular thin sheet; the first region, the second region and the third region are arranged sequentially along the length of the diamond NV color center heddle sheet, and all of them are rectangular.

[0007] Optionally, the color center concentration of the diamond NV color center heddle is in the range of 0.1ppm to 3ppm, the length of the diamond NV color center heddle is in the range of 1cm to 3cm, the width of the diamond NV color center heddle is in the range of 0.1mm to 1mm, and the thickness of the diamond NV color center heddle is ≤1mm.

[0008] Optionally, the area of ​​the second region is not less than the sum of the areas of the first region and the third region.

[0009] Optionally, the ratio of the depth of the spacer groove to the thickness of the diamond NV color center heddle sheet ranges from 90% to 95%.

[0010] Optionally, the fluorescence detection components include: a filter and a photodetector; The filter is placed on the lower surface of the diamond NV color center ensemble to filter the fluorescence excited in the corresponding region; Photodetectors are used to detect filtered fluorescence.

[0011] Optionally, the cutoff wavelength of the filter is ≥637nm.

[0012] Optionally, the laser generating device includes: a laser, a beam splitter, and a reflector; The laser emitted by the laser is split into two beams by a beam splitter. The first beam illuminates the first region, and the second beam illuminates the third region after being reflected by a mirror.

[0013] Optionally, the beam splitter can be configured with a 50:50 splitting ratio.

[0014] Optionally, the differential lock-in component includes: a transimpedance amplifier and a lock-in amplifier; The first input terminal of the transimpedance amplifier is connected to the positive terminal of the first fluorescence detection component and the negative terminal of the second fluorescence detection component, respectively. The second input terminal of the transimpedance amplifier is connected to the negative terminal of the first fluorescence detection component and the positive terminal of the second fluorescence detection component, respectively. The output of the transimpedance amplifier is connected to a lock-in amplifier.

[0015] This invention provides a vector magnetic field detection system based on diamond NV centers, comprising: a diamond NV center assemblies, a laser generator, two fluorescence detection components, two microwave antennas, a differential phase-locked loop (PLL) assembly, and a bias magnetic field generating device. The diamond NV center assemblies are provided with two spaced-apart slots, which divide the assemblies into a first region, a second region, and a third region arranged sequentially. The depth of the slots is less than the thickness of the assemblies, thus isolating the upper regions (first, second, and third) while connecting the lower regions. Two microwave antennas are respectively disposed on the upper surfaces of the first and third regions to receive modulation signals. The laser generator generates two laser beams, which illuminate the first and third regions respectively. The bias magnetic field generating device generates a bias magnetic field. The two fluorescence detection components detect the fluorescence in the first and third regions respectively and transmit the results to the differential phase-locked loop assembly. In this application, the upper layer between the first and third regions forms two relatively independent detection areas. For the far field, the magnetic field gradient between the two detection areas is negligible; however, for the bias magnetic field (near field), the magnetic field gradient between the two detection areas is not negligible. This application utilizes the difference in the perceived near and far magnetic field strengths to distinguish between the bias magnetic field and the far field, suppressing temperature drift of the bias magnetic field and common-mode noise from stray magnetic fields. Furthermore, since the two detection areas are on the same chip, they have good consistency and do not introduce directional errors, further improving detection accuracy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a vector magnetic field detection system based on diamond NV color centers provided in an embodiment of the present invention; Figure 2 This is a top view of a diamond NV color center harpoon provided in an embodiment of the present invention; Figure 3 This is a front view of a diamond NV color center ichthyometer provided in an embodiment of the present invention. Detailed Implementation

[0017] To enable those skilled in the art to better understand this solution, the technical solutions in the embodiments of this solution will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this solution, not all of them. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this solution.

[0018] The term "comprising" and any other variations thereof in the specification, claims, and accompanying drawings of this invention mean "including but not limited to," and are intended to cover a non-exclusive inclusion, not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order.

[0019] The implementation of the present invention will be described in detail below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a vector magnetic field detection system based on diamond NV color centers, provided as an embodiment of the present invention. (Refer to...) Figure 1 The vector magnetic field detection system based on diamond NV color centers includes: a diamond NV color center ensemble 1, a laser generator 2, two fluorescence detection components 3, two microwave antennas 4, a differential phase-locked loop component 5, and a bias magnetic field generating device 6. The diamond NV color center helium 1 has two spacer slots arranged at intervals, which divide the diamond NV color center helium 1 into a first region, a second region, and a third region arranged sequentially. The depth of the spacer slots is less than the thickness of the diamond NV color center helium 1, so that the first region, the second region, and the third region of the upper layer of the diamond NV color center helium 1 are isolated, while the first region, the second region, and the third region of the lower layer of the diamond NV color center helium 1 are connected. Two microwave antennas 4 are respectively disposed on the upper surface of the first region and the upper surface of the third region for receiving modulation signals; The laser generator 2 is used to generate two laser beams, which are respectively irradiated in the first region and the third region; The bias magnetic field generating device 6 is used to generate a bias magnetic field; Two fluorescence detection components 3 are used to detect the fluorescence in the first region and the fluorescence in the third region, respectively, and send the results to the differential phase-locked loop component 5.

[0020] The NV center (nitrogen-vacancy center) in diamond is a stable quantum defect with a specific energy level structure for its electron spin. Under the influence of a magnetic field, according to the Zeeman effect, the energy levels split, and the splitting distance is proportional to the magnetic field strength. When the NV center is irradiated by a laser, the electrons are excited to higher energy levels and emit fluorescence during de-excitation. The energy level splitting caused by the magnetic field changes the fluorescence intensity. When microwaves of a specific frequency are applied, electrons can resonantly transition between energy levels, resulting in a significant decrease in fluorescence intensity. By detecting the change in fluorescence intensity, the strength of the magnetic field can be inferred. However, the accuracy of magnetic field detection is limited by the temperature drift of the bias magnetic field and the influence of stray magnetic fields.

[0021] Two microwave antennas 4 transmit modulated microwave signals to the first and third regions, respectively. The modulated microwave signals enable the fluorescence intensity of the NV color center to generate a periodic signal as the magnetic field changes, facilitating subsequent phase-locked detection.

[0022] The bias magnetic field generating device 6 provides a known constant magnetic field as the bias magnetic field. The fluorescence detection component 3 is used to detect the fluorescence generated in the two regions.

[0023] refer to Figure 2 and Figure 3 In this application, the diamond NV color center ensemble 1 is divided into a first region, a second region, and a third region by a spacer groove. Each region is isolated at the top and connected at the bottom. The second region serves as an isolation zone, separating the first region and the third region, reducing the interference of edge effects on the first and third regions, and allowing the first and third regions to independently receive microwaves and lasers and generate fluorescence.

[0024] The differential phase-locked loop (PLL) module 5 performs differential fluorescence signal analysis on the two regions, which cancels out laser noise in both regions, improves the signal-to-noise ratio, and thus enhances detection accuracy. Simultaneously, because the two regions are close together, for the far field, the two regions are essentially in the same magnetic field environment, and the magnetic field gradient between them is negligible; however, for the bias magnetic field (near field), the magnetic field gradient between the two regions is not negligible. Therefore, this application utilizes the difference in perceived near and far magnetic field strength to distinguish between the bias magnetic field and the far field, and then takes measures to suppress temperature drift of the bias magnetic field and common-mode noise of stray magnetic fields, thereby achieving accurate detection of the far field (geomagnetic field).

[0025] Furthermore, the reason why diamond NV centers can be used for vector magnetic field detection is that the splitting of the electron spin energy levels of diamond NV centers is not only related to the magnetic field strength, but also closely related to the magnetic field direction. The spin axis of the NV center has a specific crystallographic orientation. When there is an angle between the external magnetic field and the spin axis of the NV center, the effective component of its Zeeman splitting will change with the angle, and the response of the fluorescence signal will also change accordingly.

[0026] Therefore, if the NV color centers of the two regions are not aligned, even if they are in the same magnetic field, the magnetic field vector components they receive will differ, directly leading to deviations in the detection signal and consequently causing misjudgments of the magnetic field direction. (Reference) Figure 3 Because the partition groove in this application does not reach the bottom, the lower layers of each region are connected, the relative positions between the first region and the third region are fixed, and the NV color center orientations of the two regions are completely consistent. No additional signal difference will be introduced due to regional orientation differences, which improves the accuracy of far-field detection and is suitable for accurate detection of the geomagnetic field.

[0027] In one possible implementation, refer to Figure 2 and Figure 3The diamond NV color center heddle sheet 1 is a rectangular thin sheet; the first region, the second region and the third region are arranged sequentially along the length of the diamond NV color center heddle sheet 1, and all of them are rectangular.

[0028] In this embodiment of the invention, two spacer slots divide the diamond sheet along its length to form a physical isolation zone, which can effectively suppress electromagnetic crosstalk between the first and third regions and enhance electromagnetic isolation between the regions. The three rectangular regions are arranged along the length, which makes the heat distribution of the system more uniform during operation, reduces measurement errors caused by temperature gradients, and improves thermal stability.

[0029] The rectangular sheet structure allows the laser to cover the first and third regions with a uniform spot, reducing fluorescence signal differences caused by spot inhomogeneity. The rectangular arrangement optimizes the microwave field distribution within the region, making it closer to a uniform field. Simultaneously, the regular arrangement makes the relationship between the fluorescence signal differences in the first and third regions more direct with the magnetic field components, reducing the computational complexity caused by complex geometries. It also lowers the manufacturing difficulty and improves the controllability and repeatability of the manufacturing process.

[0030] In one possible implementation, the color center concentration of the diamond NV color center heddle 1 ranges from 0.1ppm to 3ppm, the length of the diamond NV color center heddle 1 ranges from 1cm to 3cm, the width of the diamond NV color center heddle 1 ranges from 0.1mm to 1mm, and the thickness of the diamond NV color center heddle 1 is ≤1mm.

[0031] In this application, excessively high concentration of the diamond NV center ensemble 1 can lead to optical saturation and reduced fluorescence stability; conversely, insufficient concentration results in a weak fluorescence signal and affects detection sensitivity. Therefore, the concentration range can be 0.1ppm to 3ppm, which ensures sufficient fluorescence intensity while avoiding interference between centers and ensuring the linearity of the NV center energy level response to the magnetic field.

[0032] If the length of the diamond NV color center hexadecimal 1 is too short, it will result in insufficient area spacing, increasing the risk of microwave crosstalk and fluorescence scattering; if the length is too long, it will increase the risk of breakage and uneven light spot. Therefore, this application sets the length range to 1cm~3cm, which ensures independent operation of multiple areas while maintaining the system's compactness and signal uniformity, and is not prone to breakage. Similarly, setting the width to 0.1mm~1mm can optimize the focusing efficiency of the microwave field and laser, and enhance structural stability.

[0033] A thickness of ≤1mm ensures that the laser penetrates to the NV color center inside the thin film, while reducing the loss of fluorescence due to multiple reflections inside the diamond and improving the collection efficiency of the fluorescence detection component 3; it also reduces microwave energy loss and ensures that the NV color center receives a microwave field of sufficient intensity; and it can also ensure the consistency of the bias magnetic field throughout the region and reduce the gradient effect in the thickness direction.

[0034] In one possible implementation, the area of ​​the second region may be no less than the sum of the areas of the first region and the third region.

[0035] refer to Figure 2 and Figure 3 That is, along the length of the diamond sheet, the sum of the lengths of the first region and the third region is not greater than the length of the second region.

[0036] A larger second region can reduce cross-contamination of fluorescence scattering between the first and third regions (e.g., when the first region is irradiated by a laser, the scattered light may accidentally enter the detection range of the third region), ensuring the purity of the signal collected by the fluorescence detection component 3. At the same time, a larger second region can effectively absorb and attenuate microwave crosstalk between the first and third regions, avoiding resonance peak shift or broadening caused by mutual interference between the two microwave signals, and ensuring the independence of their respective responses to the magnetic field.

[0037] Furthermore, in one possible implementation, the area of ​​the first region is the same as the area of ​​the third region.

[0038] refer to Figure 2 That is, along the length of the diamond sheet, the length of the first region is the same as the length of the third region.

[0039] In this application, the first and third regions have the same area, meaning that the number of NV centers that can be accommodated in the two regions is essentially the same. When the laser irradiates the two regions respectively, the same irradiation area ensures that the total number of excited NV centers is similar, resulting in a more balanced baseline intensity of the fluorescence signal and reducing differential detection errors caused by differences in signal amplitude. The same area in both regions also ensures that the impact of common-mode noise is consistent, allowing for more thorough noise cancellation during differential processing and improving the signal-to-noise ratio. Furthermore, the symmetrical structure reduces manufacturing difficulty.

[0040] In one possible implementation, refer to Figure 3 The ratio of the depth of the spacer groove to the thickness of the diamond NV color center heddle sheet 1 can be in the range of 90% to 95%.

[0041] When the depth of the spacer groove reaches 90% to 95% of the sheet thickness, the groove almost penetrates the entire diamond sheet, which can significantly reduce optical crosstalk, microwave crosstalk, and thermal conduction crosstalk between different areas. At the same time, 5% to 10% of the bottom thickness is retained, which can act as a "connecting bridge" to maintain the overall structural integrity of the diamond sheet. Since the remaining thickness is extremely thin, it has almost no impact on the isolation function of the spacer groove, thus achieving a balance between "isolation effect" and "structural stability".

[0042] In one possible implementation, refer to Figure 1 The fluorescence detection component 3 may include: a filter 31 and a photodetector 32; The filter 31 is disposed on the lower surface of the diamond NV color center ensemble 1 and is used to filter the fluorescence excited in the corresponding region; The photodetector 32 is used to detect the filtered fluorescence.

[0043] The filter 31 is used to filter out interference such as scattered light from the laser, impurity fluorescence from the diamond itself, and stray light from the external environment, significantly reducing background noise and providing a high-purity optical signal for subsequent photoelectric detection.

[0044] The photodetector 32 converts optical signals into electrical signals, transforming the fluorescence signal of the NV color center into a quantifiable electrical signal for subsequent signal processing.

[0045] In one possible implementation, the cutoff wavelength of filter 31 is ≥637nm.

[0046] When the cutoff wavelength of filter 31 is ≥637nm, light of 637nm and longer wavelengths can pass through, which can cover the main energy concentration area of ​​NV color center fluorescence, ensuring that most of the effective fluorescence signal is preserved and transmitted to photodetector 32.

[0047] Meanwhile, the laser wavelength is typically set at 520nm or 532nm, and filter 31 can effectively block laser scattered light. Additionally, the wavelengths of ambient light and diamond impurity fluorescence are usually shorter, thus also blocking ambient light and diamond impurity fluorescence.

[0048] The filter 31, with a cutoff wavelength ≥637nm, precisely matches the characteristic band of NV color center fluorescence, effectively suppresses laser and short-wavelength interference, and achieves the dual goals of "maximizing effective signal retention + minimizing background noise". This improves the signal-to-noise ratio and signal purity of fluorescence detection, laying a key foundation for the subsequent extraction of weak magnetic field signals by the differential phase-locked loop component 5.

[0049] In one possible implementation, refer to Figure 1 The laser generating device 2 may include: a laser 21, a beam splitter 22, and a reflector 23; The laser emitted by laser 21 is split into two laser beams by beam splitter 22. The first laser beam illuminates the first region, and the second laser beam illuminates the third region after being reflected by mirror 23.

[0050] This application uses a beam splitter 22 and a reflector 23 to achieve the output of two laser beams. The reflector 23 only changes the optical path and does not change the laser parameters. Therefore, the two laser beams are completely identical in core parameters such as wavelength, linewidth, polarization state, and coherence, so that the excitation conditions of the first region and the third region are consistent, reducing the measurement error caused by the excitation difference of the system.

[0051] In one possible implementation, the beam splitter 22 can have a splitting ratio of 50:50.

[0052] The 50:50 beam splitting ratio of this application ensures that the power of the two laser beams is basically equal. When irradiating the first and third regions with the same area, the number of excited NV color centers and the baseline level of fluorescence emission intensity are highly consistent, avoiding the asymmetry of fluorescence signal amplitude caused by the difference in laser power and improving the signal-to-noise ratio.

[0053] In one possible implementation, the differential phase-locked component 5 may include: a transimpedance amplifier and a lock-in amplifier; The first input terminal of the transimpedance amplifier is connected to the positive terminal of the first fluorescence detection component 3 and the negative terminal of the second fluorescence detection component 3, respectively. The second input terminal of the transimpedance amplifier is connected to the negative terminal of the first fluorescence detection component 3 and the positive terminal of the second fluorescence detection component 3, respectively. The output of the transimpedance amplifier is connected to a lock-in amplifier.

[0054] In this application, differential current signals are converted into voltage signals by a wire differential amplifier for subsequent phase-locking.

[0055] In one possible implementation, the bias magnetic field generating device 6 may include a permanent magnet or an electromagnet.

[0056] The preparation method of the above system will be described in detail below with reference to specific embodiments.

[0057] Example 1: 1. Prepare a long strip of diamond NV color center hexagon 1 with a color center concentration of 1ppm, a length of 1cm, a width of 1mm, and a thickness of 0.2mm.

[0058] 2. The long diamond strip is horizontally laser-cut along its length to a depth of 90% of its thickness, and is divided into three regions by two cuts; the first region is 1mm×1mm in size, the second region is 8mm×1mm in size, and the third region is 1mm×1mm in size.

[0059] 3. Filters 31 are respectively set below the first region and the third region, and the cutoff wavelength of the filters 31 is ≥637nm; 4. Photodetectors 32 are respectively set below the two filters 31, and the diameter of the photosensitive unit of the photodetector 32 is 2mm.

[0060] 5. Microwave antennas 4 are installed above the first and third regions respectively.

[0061] 6. Arrange laser 21 with a laser wavelength of 520nm; the beam splitter 22 has a beam splitting ratio of 50:50; 7. Two photodetectors are differentially connected to a transimpedance amplifier and a lock-in amplifier using 32-wire differential connections; 8. Set the bias magnetic field for the permanent magnet.

[0062] Example 2: 1. Prepare a long strip of diamond NV color center hexagon 1 with a color center concentration of 0.3ppm, a length of 2cm, a width of 2mm, and a thickness of 0.2mm.

[0063] 2. The long diamond strip is horizontally laser-cut along its length to a depth of 90% of its thickness, and is divided into three regions by two cuts; the first region is 2mm×2mm in size, the second region is 16mm×2mm in size, and the third region is 2mm×2mm in size.

[0064] 3. Filters 31 are respectively set below the first region and the third region, and the cutoff wavelength of the filters 31 is ≥637nm; 4. Photodetectors 32 are respectively set below the two filters 31, and the diameter of the photosensitive unit of the photodetector 32 is 3mm.

[0065] 5. Microwave antennas 4 are installed above the first and third regions respectively.

[0066] 6. Arrange laser 21 with a laser wavelength of 532nm; the beam splitter 22 has a beam splitting ratio of 50:50; 7. Two photodetectors are differentially connected to a transimpedance amplifier and a lock-in amplifier using 32-wire differential connections; 8. Set the bias magnetic field for the permanent magnet.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vector magnetic field detection system based on diamond NV color centers, characterized in that, include: Diamond NV color center array, laser generator, two fluorescence detection components, two microwave antennas, differential phase-locked loop assembly and bias magnetic field generator; The diamond NV color center heddle has two spaced-apart slots that divide it into a first region, a second region, and a third region arranged sequentially. The depth of the spaced-apart slots is less than the thickness of the diamond NV color center heddle, so that the first region, the second region, and the third region on the upper layer of the diamond NV color center heddle are isolated, while the first region, the second region, and the third region on the lower layer of the diamond NV color center heddle are connected. The two microwave antennas are respectively disposed on the upper surface of the first region and the upper surface of the third region, for receiving modulation signals; The laser generating device is used to generate two laser beams, which are respectively irradiated in the first region and the third region; The bias magnetic field generating device is used to generate a bias magnetic field; The two fluorescence detection components are used to detect the fluorescence in the first region and the fluorescence in the third region, respectively, and send the results to the differential phase-locked loop component.

2. The vector magnetic field detection system based on diamond NV color centers as described in claim 1, characterized in that, The diamond NV color center heddle sheet is a rectangular thin sheet; the first region, the second region and the third region are arranged sequentially along the length of the diamond NV color center heddle sheet, and all of them are rectangular.

3. The vector magnetic field detection system based on diamond NV color centers as described in claim 2, characterized in that, The diamond NV color center heddle has a color center concentration range of 0.1ppm to 3ppm, a length range of 1cm to 3cm, a width range of 0.1mm to 1mm, and a thickness of ≤1mm.

4. The vector magnetic field detection system based on diamond NV color centers as described in claim 2, characterized in that, The area of ​​the second region is not less than the sum of the areas of the first region and the third region.

5. The vector magnetic field detection system based on diamond NV color centers as described in any one of claims 1 to 4, characterized in that, The ratio of the depth of the spacer groove to the thickness of the diamond NV color center ensemble sheet ranges from 90% to 95%.

6. The vector magnetic field detection system based on diamond NV color centers as described in any one of claims 1 to 4, characterized in that, The fluorescence detection component includes: a filter and a photodetector; The filter is disposed on the lower surface of the diamond NV color center ensemble and is used to filter the fluorescence excited in the corresponding region. The photodetector is used to detect the filtered fluorescence.

7. The vector magnetic field detection system based on diamond NV color centers as described in claim 6, characterized in that, The cutoff wavelength of the filter is ≥637nm.

8. The vector magnetic field detection system based on diamond NV color centers as described in any one of claims 1 to 4, characterized in that, The laser generating device includes: a laser, a beam splitter, and a reflector; The laser emitted by the laser is split into two laser beams by the beam splitter. The first laser beam illuminates the first region, and the second laser beam illuminates the third region after being reflected by the reflector.

9. The vector magnetic field detection system based on diamond NV color centers as described in claim 8, characterized in that, The beam splitter has a splitting ratio of 50:

50.

10. The vector magnetic field detection system based on diamond NV color centers as described in any one of claims 1 to 4, characterized in that, The differential phase-locked module includes: a transimpedance amplifier and a lock-in amplifier; The first input terminal of the transimpedance amplifier is connected to the positive terminal of the first fluorescence detection component and the negative terminal of the second fluorescence detection component, respectively. The second input terminal of the transimpedance amplifier is connected to the negative terminal of the first fluorescence detection component and the positive terminal of the second fluorescence detection component, respectively. The output of the transimpedance amplifier is connected to the lock-in amplifier.

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