A wide-field magnetic imaging system based on diamond nitrogen-vacancy color centers and a fault detection method

Abstract

The application discloses a wide-field magnetic imaging system and a fault detection method based on a diamond nitrogen-vacancy color center. The wide-field magnetic imaging system comprises a laser excitation unit for generating and forming a uniform excitation light field to irradiate a diamond NV color center sensor; a fluorescence collection and imaging unit for collecting fluorescence emitted by the NV color center under excitation and forming a wide-field fluorescence image, comprising an objective lens, a filter and a camera; a signal processing and control unit electrically connected with the laser excitation unit and the fluorescence collection and imaging unit, for controlling the system timing, and processing the intensity information of the wide-field fluorescence image to obtain a two-dimensional distribution map of the measured magnetic field.

Description

Technical Field

[0001] This invention relates to the fields of quantum sensing and magnetic measurement technology, and more specifically, to a wide-field magnetic imaging system and fault detection method based on diamond nitrogen-vacancy color centers. Background Technology

[0002] In industrial sectors such as aerospace, rail transportation, and electrical engineering, early fault diagnosis of critical components under extreme environments such as high temperature and high field is crucial. Existing non-destructive testing technologies, such as ultrasonic testing, either have limited penetration depth or require bulky equipment and safety protection measures, making it difficult to achieve rapid and accurate location and morphology reconstruction of microscopic defects inside components.

[0003] Magnetic measurement technology, which inverses defect information by detecting magnetic anomalies caused by conductor defects, is a potential non-destructive testing method. However, traditional magnetic sensors (such as Hall sensors and TMRs) have low sensitivity and spatial resolution, and are mostly electronic devices, making high-voltage insulation difficult. While optically pumped magnetometers have high sensitivity, they are scalar measurements with limited dynamic range. Magnetic sensing technology based on diamond NV centers has advantages such as high spatial resolution and room-temperature operation, but existing high spatial resolution magnetic imaging methods based on diamond NV center systems are slow and have high environmental requirements, making them difficult to apply in most scenarios. Therefore, this application proposes a magnetic imaging method using an integrated wave scheme to address the aforementioned problems. Summary of the Invention

[0004] According to the present invention, a wide-field magnetic imaging method and fault detection method and system based on diamond nitrogen-vacancy color centers are provided to overcome the shortcomings of existing non-destructive testing technologies in terms of detection efficiency, sensitivity to deep defects, adaptability to complex components, and ease of on-site deployment. The present invention provides a full-optical wide-field magnetic imaging method and sensor based on energy level aliasing effect without microwave control, enabling high-efficiency, high-resolution magnetic visualization detection of various industrial faulty components in extreme environments such as high temperature and high field.

[0005] According to a first aspect of the present invention, a wide-field magnetic imaging system based on diamond nitrogen-vacancy color centers is provided, comprising: A laser excitation unit is used to generate and form a uniform excitation light field to irradiate the diamond NV color center sensor; A fluorescence collection and imaging unit, used to collect fluorescence excited by the NV color center and form a wide-field fluorescence image, includes an objective lens, a filter, and a camera; The signal processing and control unit is electrically connected to the laser excitation unit and the fluorescence collection and imaging unit. It is used to control the system timing and process the intensity information of the wide-field fluorescence image to invert the two-dimensional distribution map of the magnetic field to be measured.

[0006] Optionally, it may also include a reference optical path module; The reference optical path module is used to monitor laser power fluctuations in real time and provide compensation and correction signals to the signal processing and control unit, including a beam splitter and a reference photodetector.

[0007] Optionally, it also includes a microwave excitation unit; The microwave excitation unit, used to apply a controllable microwave field to the NV color center, enables the system to switch between all-optical mode and photodetector magnetic resonance mode, and includes a microwave source, a power amplifier, and a radiation structure.

[0008] Optionally, it also includes a bias magnetic field module; The bias magnetic field module is an electromagnetic coil or a permanent magnet array, used to generate a controllable bias magnetic field at the NV color center. The bias magnetic field is one of a uniform magnetic field, an alternating magnetic field, or a gradient magnetic field.

[0009] According to another aspect of the present invention, an integrated magnetic imaging system based on diamond nitrogen-vacancy color centers is also provided, comprising: A laser excitation unit is used to generate and form a uniform excitation light field to irradiate the diamond NV color center sensor; The nanofiber bundle unit is used to excite laser light to be transmitted to the NV color center, generate fluorescence signal and transmit it in reverse to the detector array. It is composed of multiple single-mode optical fibers with diameters ranging from micrometers to nanometers. One end of the fiber serves as the detection end, with NV color center material optically bonded or directly integrated thereon; the other end serves as the coupling end, used to receive the excitation laser light and transmit the generated fluorescence signal in reverse. The signal processing and reconstruction unit is used to reconstruct the magnetic field distribution image of the surface of the object under test based on the fluorescence intensity signal received from each optical fiber by the detector array.

[0010] Optionally, it also includes a reference optical path module for real-time monitoring of fluctuations in the intensity of the emitted light from the laser excitation unit; The reference optical path module is implemented in one of the following two ways: It consists of a beam splitter and a reference photodetector; or It consists of at least one dedicated reference fiber integrated in the nanofiber bundle unit and a corresponding reference detector.

[0011] Optionally, it also includes a microwave excitation unit for applying a controllable microwave field to the NV color center; The signal processing and reconstruction unit is connected to the microwave excitation unit and controls its working state, enabling the sensor to switch between an all-optical mode without a microwave field and a photodetector magnetic resonance mode with a microwave field.

[0012] According to another aspect of the present invention, a fault detection method based on magnetic imaging of diamond nitrogen-vacancy color centers is also provided, comprising: The sensor probe, which integrates diamond-position NV color center material, is brought close to the surface of the component under test. A laser excitation unit is used to generate and transmit excitation light to a diamond NV color center material, causing it to emit fluorescence. The fluorescence is collected, and a fluorescence intensity image is acquired. Based on the pre-calibrated relationship between fluorescence intensity and magnetic field strength, the fluorescence intensity image is converted into a magnetic induction intensity distribution image; Analyze the distribution, morphology, and intensity characteristics of magnetic anomaly regions in the magnetic induction intensity distribution image to identify and locate defects such as cracks, corrosion, inclusions, or stress concentration areas inside the component.

[0013] Optionally, before acquiring the fluorescence intensity image, the method further includes: A transverse bias magnetic field is applied to the diamond NV center material to induce NV center energy level aliasing.

[0014] Optionally, before acquiring the fluorescence intensity image, the method further includes: A microwave field is applied to the diamond NV color center material, and the microwave frequency is scanned; A photodetector magnetic resonance spectrum method is used to obtain the fluorescence intensity as a function of microwave frequency.

[0015] Therefore, by employing an all-optical magnetic measurement mechanism, eliminating the need for a microwave system, the system complexity, cost, and power consumption are significantly reduced, while simultaneously enhancing stability and reliability under electromagnetic interference environments. Based on the energy level aliasing effect, a linear magnetic field response can be achieved within the 5–40 mT range, providing direct detection capability in strong fields, suitable for strong magnetic field scenarios such as current-carrying wires and permanent magnets. Wide-field imaging combined with area array detection allows for the acquisition of the entire magnetic field distribution in a single exposure, with detection efficiency far exceeding that of point-by-point scanning methods. The use of nanofiber bundles to achieve micron-level sensing probes significantly reduces system size while ensuring high spatial resolution of magnetic imaging. Flexible microprobes can penetrate into narrow spaces and complex structures, enabling "endoscopic" in-situ magnetic imaging, expanding the application scenarios of industrial non-destructive testing. Possessing vector and high-resolution imaging potential, it can clearly extract the location, morphology, and size of defects, providing a new technological means for rapid, visualized non-destructive diagnosis of industrial components. Attached Figure Description

[0016] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures: Figure 1 This is a schematic diagram of a magnetic imaging system based on diamond nitrogen-vacancy color centers; Figure 2This is a schematic diagram of an integrated magnetic imaging system based on diamond nitrogen-vacancy color centers; Figure 3 This is a schematic diagram of the spin aliasing effect of diamond NV color centers caused by a transverse magnetic field. Detailed Implementation

[0017] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0018] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0019] This invention addresses the technical problems existing in the prior art by proposing a quantum magnetometry imaging method that does not require a microwave system or a bias field.

[0020] This invention provides a full-optical wide-field magnetic imaging sensor based on diamond NV centers and a method for detecting industrial faulty parts. Its core lies in utilizing the NV center energy level aliasing effect caused by a transverse bias magnetic field to achieve wide-field imaging of the magnetic field by measuring changes in fluorescence intensity. The specific scheme is as follows: The sensor system can be divided into two schemes, which include: According to a first aspect of the present invention, a wide-field magnetic imaging system based on diamond nitrogen-vacancy color centers comprises: A laser excitation unit is used to generate and form a uniform excitation light field to irradiate the diamond NV color center sensor; A fluorescence collection and imaging unit, used to collect fluorescence excited by the NV color center and form a wide-field fluorescence image, includes an objective lens, a filter, and a camera; The signal processing and control unit is electrically connected to the laser excitation unit and the fluorescence collection and imaging unit. It is used to control the system timing and process the intensity information of the wide-field fluorescence image to invert the two-dimensional distribution map of the magnetic field to be measured.

[0021] Optionally, it may also include a reference optical path module; The reference optical path module is used to monitor laser power fluctuations in real time and provide compensation and correction signals to the signal processing and control unit, including a beam splitter and a reference photodetector.

[0022] Optionally, it also includes a microwave excitation unit; The microwave excitation unit, used to apply a controllable microwave field to the NV color center, enables the system to switch between all-optical mode and photodetector magnetic resonance mode, and includes a microwave source, a power amplifier, and a radiation structure.

[0023] Optionally, it also includes a bias magnetic field module; The bias magnetic field module is an electromagnetic coil or a permanent magnet array, used to generate a controllable bias magnetic field at the NV color center. The bias magnetic field is one of a uniform magnetic field, an alternating magnetic field, or a gradient magnetic field.

[0024] Specifically, refer to Figure 1 As shown, Scheme 1 is a wide-field imaging sensor based on a traditional optical system. Laser excitation unit: A laser or laser diode used to generate 532nm laser light, which is expanded and shaped to form a uniform light field that irradiates the diamond NV color center sensor.

[0025] Fluorescence collection and imaging unit: including objective lens, filter and CCD or sCMOS camera, used to collect fluorescence emitted by NV color center and form wide-field fluorescence image.

[0026] Signal processing and control unit: controls the probe position and laser timing, and inverts the two-dimensional distribution map of the magnetic field to be measured based on the fluorescence image intensity.

[0027] Reference optical path module (optional): Used for real-time monitoring of laser power fluctuations, implemented through a beam splitter and a reference photodetector. This module is used to compensate for the impact of laser fluctuations on fluorescence measurement results.

[0028] Microwave Control Module: The system can be further integrated with an optional microwave excitation unit, including a microwave source, power amplifier, and radiating structure (such as a microwave coil, coplanar waveguide, or stripline). This unit allows the system to switch between "all-optical mode" and "high-sensitivity ODMR mode." When the magnetic field to be measured is weak, imaging of a magnetic field at a specific frequency is required, or higher sensitivity and linearity are needed, the microwave system can be activated for conventional continuous wave or pulsed ODMR measurements.

[0029] Bias Magnetic Field Module: This module uses coils or magnet arrays to generate a controllable bias magnetic field within a range at the NV color center. It can generate uniform, alternating, or gradient magnetic fields to meet requirements for higher magnetic measurement sensitivity, higher magnetic field direction resolution, and higher magnetic field spatial resolution.

[0030] According to another aspect of the present invention, an integrated magnetic imaging system based on diamond nitrogen-vacancy color centers is also provided, comprising: A laser excitation unit is used to generate and form a uniform excitation light field to irradiate the diamond NV color center sensor; The nanofiber bundle unit is used to excite laser light to be transmitted to the NV color center, generate fluorescence signal and transmit it in reverse to the detector array. It is composed of multiple single-mode optical fibers with diameters ranging from micrometers to nanometers. One end of the fiber serves as the detection end, with NV color center material optically bonded or directly integrated thereon; the other end serves as the coupling end, used to receive the excitation laser light and transmit the generated fluorescence signal in reverse. The signal processing and reconstruction unit is used to reconstruct the magnetic field distribution image of the surface of the object under test based on the fluorescence intensity signal received from each optical fiber by the detector array.

[0031] Optionally, it also includes a reference optical path module for real-time monitoring of fluctuations in the intensity of the emitted light from the laser excitation unit; The reference optical path module is implemented in one of the following two ways: It consists of a beam splitter and a reference photodetector; or It consists of at least one dedicated reference fiber integrated in the nanofiber bundle unit and a corresponding reference detector.

[0032] Optionally, it also includes a microwave excitation unit for applying a controllable microwave field to the NV color center; The signal processing and reconstruction unit is connected to the microwave excitation unit and controls its working state, enabling the sensor to switch between an all-optical mode without a microwave field and a photodetector magnetic resonance mode with a microwave field.

[0033] Specifically, refer to Figure 2 As shown, Scheme 2 is a miniaturized imaging sensor based on nanofiber bundles. The laser excitation unit described in Scheme 1 is replaced with a laser or laser diode for generating 532nm laser light.

[0034] Based on Scheme 1, a nanofiber bundle unit is added. This unit consists of multiple single-mode optical fibers with diameters ranging from micrometers to nanometers that are tightly arranged and integrated. One end of the fiber bundle is closely attached to the fiber bundle and bonded with optical adhesive or integrated with NV color center materials (such as nanodiamond powder, nanodiamond film, or bulk diamond surface). The laser emitted by the laser excitation unit is coupled into the other end of the nanofiber bundle after certain processing. In addition, the fluorescence collection and imaging unit described in Scheme 1 will also obtain a wide-field fluorescence image through the fluorescence returned from this end.

[0035] The reference optical path module described in Scheme 1 is implemented by a beam splitter and a reference photodetector or a dedicated reference fiber in a fiber bundle.

[0036] The fluorescence collection and detection unit described in Scheme 1 is replaced by a cluster of nanofibers that simultaneously transmits the excitation laser to the NV color center and conducts the generated fluorescence signal in reverse to the detector array (such as an APD array or an sCMOS camera). Each independent fiber or fiber cluster corresponds to one imaging pixel.

[0037] Signal processing and reconstruction unit: Based on the fluorescence intensity signal received from each optical fiber by the detector array, it reconstructs the magnetic field distribution image of the surface of the object under test.

[0038] According to another aspect of the present invention, a fault detection method based on magnetic imaging of diamond nitrogen-vacancy color centers is also provided, comprising: The sensor probe, which integrates diamond-position NV color center material, is brought close to the surface of the component under test. A laser excitation unit is used to generate and transmit excitation light to a diamond NV color center material, causing it to emit fluorescence. The fluorescence is collected, and a fluorescence intensity image is acquired. Based on the pre-calibrated relationship between fluorescence intensity and magnetic field strength, the fluorescence intensity image is converted into a magnetic induction intensity distribution image; Analyze the distribution, morphology, and intensity characteristics of magnetic anomaly regions in the magnetic induction intensity distribution image to identify and locate defects such as cracks, corrosion, inclusions, or stress concentration areas inside the component.

[0039] Optionally, before acquiring the fluorescence intensity image, the method further includes: A transverse bias magnetic field is applied to the diamond NV center material to induce NV center energy level aliasing, referenced. Figure 3 As shown.

[0040] Optionally, before acquiring the fluorescence intensity image, the method further includes: A microwave field is applied to the diamond NV color center material, and the microwave frequency is scanned; A photodetector magnetic resonance spectrum method is used to obtain the fluorescence intensity as a function of microwave frequency.

[0041] Specifically, the faulty component detection method includes the following steps: The first step is to pre-treat the component to be tested. The main treatment methods are to choose whether to sprinkle magnetic powder, apply current excitation, or externally magnetize it, depending on the characteristics of the component.

[0042] The second step is to bring the sensor probe close to the surface of the component to be tested.

[0043] The third step is to select the working mode and configuration according to the requirements (all-optical without bias field, all-optical with bias field, or ODMR mode). The fourth step is to turn on the laser excitation unit to uniformly irradiate the diamond NV color center and use the fluorescence collection and imaging unit to acquire a fluorescence intensity image.

[0044] The fifth step involves converting the fluorescence image into a magnetic induction intensity distribution image based on the pre-calibrated "fluorescence intensity-magnetic field intensity" relationship.

[0045] The sixth step is to analyze the distribution, morphology, and intensity characteristics of the magnetic anomaly region, and combine image processing or machine learning algorithms to identify and locate defects such as cracks, corrosion, inclusions, or stress concentration areas inside the component.

[0046] Use such as Figure 1 The wide-field magnetic imaging system shown is used for the visual detection and identification of internal defects in power cables. In this application scenario, the magnetic field to be tested is large and has a significant magnetic field gradient; therefore, the test can be performed using a biasless all-optical mode. The first step involves aligning the sensor probe with the surface of the cable under test for wide-field magnetic imaging. The second step allows for clear observation of the magnetic anomaly distribution caused by defects in the acquired magnetic image. The third step involves analyzing the intensity and distribution pattern of the magnetic anomaly, and combining this with a pre-trained deep learning model (such as a convolutional neural network), automatically identifying the type (e.g., transverse cracks, oblique cracks), size, and depth of the defect, achieving accurate assessment of the cable's condition and fault warning. This method overcomes the limitations of infrared thermal imagers in detecting internal defects and ultrasonic detection being susceptible to noise interference.

[0047] Use such as Figure 2 The wide-field magnetic imaging system shown is used to detect eddy current damage inside the GIS housing. This embodiment is designed for large power equipment such as gas-insulated switchgear (GIS), whose metal housing may experience localized overheating and even microscopic damage due to eddy current effects during long-term operation. These defects are located inside the equipment and are difficult to access using traditional detection methods. The first step involves applying a working current or a dedicated excitation current to the GIS housing. Areas with microscopic damage or material inhomogeneity will disturb the eddy current field on the housing surface, generating localized magnetic anomalies. The second step involves inserting a fiber optic probe into the equipment through the inspection port. In a bias-free, all-optical mode, an image of the magnetic distribution on the inner surface of the housing can be acquired. The third step involves analyzing this image to achieve a direct and visual assessment of the internal condition of the GIS housing, effectively preventing faults caused by localized overheating of the housing.

[0048] Use such as Figure 1 The wide-field magnetic imaging system shown, in ODMR mode, provides precise diagnosis of the contact condition of high-voltage circuit breaker contacts. This embodiment addresses the problem of increased contact resistance in high-voltage circuit breaker contacts due to aging and erosion. This defect alters the current distribution, causing weak local magnetic anomalies that require extremely high measurement sensitivity for detection. The first step involves applying a rated current to the circuit breaker contacts; the second step is in ODMR mode, as shown... Figure 1 The wide-field magnetic imaging system shown is located near the area carrying the rated current. The third step involves reconstructing the magnetic field map of the current distribution on the contact surface using the test structure. By analyzing the uniformity of the magnetic field distribution, poorly contacted contact points can be accurately located, and the degree of increase in contact resistance can be quantified. This provides a direct and reliable basis for condition-based maintenance of the circuit breaker, preventing major accidents caused by contact overheating.

[0049] This invention relates to the field of quantum sensing and magnetic measurement technology, and more specifically, to imaging spatial magnetic fields by utilizing the nanoscale properties of diamond NV color centers in combination with CMOS or fiber optic bundles. This magnetic imaging method achieves sub-micron level spatial resolution and exhibits good environmental adaptability. Specific implementation methods include: firstly, reducing system complexity by employing a microwave-free approach, enabling it to adapt to extreme environments such as high fields and high pressures; secondly, increasing spatial compatibility by using fiber optic bundles; and thirdly, employing multiple optional modules for more flexible matching to various application scenarios.

[0050] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0051] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0052] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0053] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0054] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0055] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A wide-field magnetic imaging system based on diamond nitrogen-vacancy color centers, characterized in that, include: A laser excitation unit is used to generate and form a uniform excitation light field to irradiate the diamond NV color center sensor; A fluorescence collection and imaging unit, used to collect fluorescence excited by the NV color center and form a wide-field fluorescence image, includes an objective lens, a filter, and a camera; The signal processing and control unit is electrically connected to the laser excitation unit and the fluorescence collection and imaging unit. It is used to control the system timing and process the intensity information of the wide-field fluorescence image to invert the two-dimensional distribution map of the magnetic field to be measured.

2. The wide-field magnetic imaging system according to claim 1, characterized in that, It also includes a reference optical path module; The reference optical path module is used to monitor laser power fluctuations in real time and provide compensation and correction signals to the signal processing and control unit, including a beam splitter and a reference photodetector.

3. The wide-field magnetic imaging system according to claim 1, characterized in that, It also includes a microwave excitation unit; The microwave excitation unit, used to apply a controllable microwave field to the NV color center, enables the system to switch between all-optical mode and photodetector magnetic resonance mode, and includes a microwave source, a power amplifier, and a radiation structure.

4. The wide-field magnetic imaging system according to claim 1, characterized in that, It also includes a bias magnetic field module; The bias magnetic field module is an electromagnetic coil or a permanent magnet array, used to generate a controllable bias magnetic field at the NV color center. The bias magnetic field is one of a uniform magnetic field, an alternating magnetic field, or a gradient magnetic field.

5. An integrated magnetic imaging system based on diamond nitrogen-vacancy color centers, characterized in that, include: A laser excitation unit is used to generate and form a uniform excitation light field to irradiate the diamond NV color center sensor; The nanofiber bundle unit is used to excite laser transmission to the NV color center, generate fluorescence signal and conduct it in reverse to the detector array. It consists of multiple single-mode optical fibers with diameters ranging from micrometers to nanometers, tightly arranged and integrated. One end of the fiber serves as the detection end, and the NV color center material is optically bonded or directly integrated. Its other end serves as a coupling end, used to receive the excitation laser and transmit the generated fluorescence signal in reverse; The signal processing and reconstruction unit is used to reconstruct the magnetic field distribution image of the surface of the object under test based on the fluorescence intensity signal received from each optical fiber by the detector array.

6. The integrated magnetic imaging system according to claim 5, characterized in that, It also includes a reference optical path module for real-time monitoring of fluctuations in the intensity of the light emitted from the laser excitation unit; The reference optical path module is implemented in one of the following two ways: It consists of a beam splitter and a reference photodetector; or It consists of at least one dedicated reference fiber integrated in the nanofiber bundle unit and a corresponding reference detector.

7. The integrated magnetic imaging system according to claim 5, characterized in that, It also includes a microwave excitation unit for applying a controllable microwave field to the NV color center; The signal processing and reconstruction unit is connected to the microwave excitation unit and controls its working state, enabling the sensor to switch between an all-optical mode without a microwave field and a photodetector magnetic resonance mode with a microwave field.

8. A fault detection method based on magnetic imaging of diamond nitrogen-vacancy color centers, characterized in that, include: The sensor probe, which integrates diamond-position NV color center material, is brought close to the surface of the component under test. A laser excitation unit is used to generate and transmit excitation light to a diamond NV color center material, causing it to emit fluorescence. The fluorescence is collected, and a fluorescence intensity image is acquired. Based on the pre-calibrated relationship between fluorescence intensity and magnetic field strength, the fluorescence intensity image is converted into a magnetic induction intensity distribution image; Analyze the distribution, morphology, and intensity characteristics of magnetic anomaly regions in the magnetic induction intensity distribution image to identify and locate defects such as cracks, corrosion, inclusions, or stress concentration areas inside the component.

9. The fault detection method according to claim 8, characterized in that, Before acquiring the fluorescence intensity image, the following steps are also included: A transverse bias magnetic field is applied to the diamond NV center material to induce NV center energy level aliasing.

10. The fault detection method according to claim 8, characterized in that, Before acquiring the fluorescence intensity image, the following steps are also included: A microwave field is applied to the diamond NV color center material, and the microwave frequency is scanned; The optical detection magnetic resonance spectrum is obtained by measuring the change in fluorescence intensity with microwave frequency.

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