Sensing structure and nondestructive testing device

Abstract

The invention relates to the technical field of quantum sensing, and provides a sensing structure and a nondestructive testing device.The sensing structure comprises a wide-field sensing unit, an objective lens, a driving lever, a plurality of reflective lenses and a spatial light path; the wide-field sensing unit can achieve wide-field measurement and obtain overall information of a defect area, meanwhile, the array type measurement structure can extend the measurement range in the longitudinal direction, and due to the structural design that the reflective lens and the gear lever are combined, the incident position of laser can be accurately switched, and the measurement accuracy is improved. Therefore, segmented irradiation of a plurality of detection areas can be realized through a single light source.

Description

Technical Field

[0001] The present invention relates to the field of quantum sensing technology, and in particular to a sensing structure and a nondestructive testing device. Background Art

[0002] NV (nitrogen-vacancy) color centers in diamond are a common diamond defect, which is formed by a nitrogen atom replacing a carbon atom in the diamond lattice, and there is a vacancy (i.e., a missing carbon atom) in the adjacent lattice. This structure causes changes in the surrounding electronic state, thereby changing the absorption and emission characteristics of diamond in the visible spectrum, producing specific colors. It is common to use 532 wavelength green excitation light to excite the NV color center, and correspondingly, the NV color center will produce red feedback fluorescence; and changes in some physical fields (such as magnetic fields, temperature, etc.) will cause specific changes in the red fluorescence it produces, and based on these specific changes, sensing measurements of specific physical fields can be achieved.

[0003] For example, a Chinese invention patent with authorization announcement number CN117705932B proposes a quantum nondestructive sensor and a rail surface defect detection machine, which utilizes an optical fiber-diamond NV color center probe to perform nondestructive detection of surface defects of ferromagnetic materials. It can accurately detect the leakage magnetic field on a single path. However, at present, the volume of diamonds containing NV color centers used in sensing detection is generally at the micron level, and the measurement coverage area is small, and the overall information of the defective area cannot be quickly obtained. In order to improve the rapid and sufficient detection of defective areas, the present invention proposes a corresponding solution. Summary of the invention

[0004] The present invention proposes a sensing structure and a nondestructive testing device to solve the problems existing in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions: A sensing structure comprising: A wide-field sensing unit, comprising a plurality of detection areas containing NV color centers, the top surface of the detection area being a fluorescence output surface, a light incident port being arranged in the side surface of each detection area, and all the light incident ports being located on the same side, wherein the NV color center generates feedback fluorescence under the irradiation of excitation light of a specific wavelength; an objective lens adapted to be disposed directly above the wide field sensing unit and configured to be movable along the length direction of the wide field sensing unit; A lever connected to the lower side of the objective lens; A plurality of reflective lenses, which are arranged one by one in front of the light incident port, and the reflective lenses are configured such that: when the lever moves to the light incident port, the reflective lenses are driven by the lever to rotate to a set angle, and when the lever moves away from the light incident port, the reflective lenses return to being parallel to the surface where the light incident port is located; The spatial light path is used to transmit the excitation light, and is configured such that when any reflective lens is rotated to a set angle, the excitation light transmitted in the spatial light path is guided into a light incident port at a corresponding position by reflection.

[0006] Furthermore, the wide-field sensing unit is formed by a row of transparent substrates connected to each other, the transparent substrates contain NV color centers, each of the transparent substrates includes a first surface, a second surface and a substrate peripheral side surface, the substrate peripheral side surface is provided with a light incident port, the excitation light enters from the light incident port, the substrate peripheral side surface other than the incident port and the first surface are provided with reflective media, the second surface is a fluorescence output surface, a filter medium for filtering out feedback fluorescence is provided thereon, and the objective lens is used to magnify the second surface.

[0007] Furthermore, the filter medium is also used to reflect the excitation light.

[0008] Furthermore, it also includes a wide-field camera, which is mounted on the objective lens and is configured to move with the objective lens.

[0009] Furthermore, it comprises a tube body, one side of which is provided with a through opening facing the light incident port, the reflective lens is rotatably arranged in the tube body, a rotating shaft is provided in the middle of the top of the reflective lens, the rotating shaft passes through the top surface of the tube body and is connected to a gear lever, a rotation return spring is provided between the rotating shaft and the tube body, wherein when the lever moves to the light incident port, the gear lever is driven by the lever to rotate to a set angle.

[0010] Furthermore, a slide groove adapted to the moving track of the lever is provided on the top surface of the tube body, and the bottom of the lever is slidably connected to the slide groove.

[0011] Furthermore, it also includes a microwave radiator, which is used to radiate a microwave field toward the transparent substrate.

[0012] Furthermore, there is one microwave radiator, which is configured to move with the objective lens.

[0013] On the other hand, the present invention also provides a non-destructive testing device, which applies one or more sensing structures as described above.

[0014] Furthermore, a magnetizer is provided, which is used to magnetize the object to be tested so as to generate leakage magnetic fields at the surface defects of the object for sensing by the sensing structure.

[0015] Compared with the prior art, the beneficial effects of the present invention are: the wide-field sensing unit in the present invention can realize wide-field measurement and obtain overall information of the defect area. At the same time, the array-type measurement structure can extend the measurement range in the longitudinal direction, and the structural design of the combination of the reflective lens and the gear lever enables the laser to accurately switch the incident position, thereby realizing segmented irradiation of multiple detection areas through a single light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0017] Figure 1 is a schematic diagram of the sensing structure in Example 1; Figure 2 is a schematic diagram of the transparent substrate and its accessories in Example 1; Figure 3 for Figure 1 The enlarged schematic diagram at A in the middle; Figure 4 is a schematic diagram of the sensing structure with a tube body in Example 1; Figure 5 is a cross-sectional view of the interior of the tube body in Example 1; Figure 6 is a schematic structural diagram of the bottom plate in Example 1; Figure 7 Schematic diagram of the nondestructive testing device in Example 2. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. <Example 1>

[0019] See attached Figure 1 This example introduces a sensing structure, which includes a wide-field sensing unit, an objective lens 3, a lever 4, a plurality of reflective lenses 5 and a spatial optical path 6.

[0020] In this example, the wide-field sensing unit includes a plurality of detection areas 1 containing NV color centers, the top surface of the detection area 1 is a fluorescence output surface, a light incident port 2 is provided in the side surface of each detection area 1, and all light incident ports 2 are on the same side, wherein the NV color center will generate feedback fluorescence under the irradiation of excitation light of a specific wavelength. In the exemplary scheme, as shown in the attached Figure 2 As shown, the wide-field sensing unit is formed by a row of transparent substrates 101 connected to each other, the transparent substrates 101 contain NV color centers, each transparent substrate 101 includes a first surface, a second surface and a substrate peripheral side surface, a light incident port 2 is arranged on the substrate peripheral side surface, the excitation light enters from the light incident port 2, and the substrate peripheral side surface and the first surface except the light incident port 2 are provided with a reflective medium 102, the second surface is a fluorescence output surface, and a filter medium 103 for filtering out feedback fluorescence is provided thereon, and the objective lens 3 is used to magnify the second surface.

[0021] Among them, the transparent substrate 101 can be a diamond block with NV color centers evenly distributed inside. However, in this option, based on the difficulty and cost of manufacturing large-sized diamond blocks, the overall size of the transparent substrate 101 is difficult to be enlarged, and it is difficult to obtain a larger-sized detection imaging effect. Considering this problem, in another scheme, the transparent substrate 101 is designed to have diamond particles evenly distributed inside with ensemble NV color centers. In this scheme, the transparent substrate 101 is a non-diamond transparent material, such as epoxy resin, and the size of the diamond particles is nanometer-level. In this example, the light incident port 2 is set on the side of the substrate, and the excitation light enters from the light incident port 2; taking the transparent substrate 101 as a rectangular thin block as an example, the light incident port 2 is set on its side, considering that part of the excitation light and feedback fluorescence will leak from this position and cause waste, in order to reduce waste, the area of ​​the light incident port 2 should be minimized while ensuring that the excitation light fully enters; in addition, in order to avoid the light reflection waste generated when the excitation light enters the light incident port 2, in some preferred designs, a layer of anti-reflection film is also designed on the surface of the light incident port 2. In this example, the reflective medium 102 is arranged on the surrounding side surfaces of the substrate and the first surface except the light incident port 2; taking the transparent substrate 101 as a rectangular thin block as an example, the reflective medium 102 is arranged on the bottom surface of the rectangular thin block and all side portions except the light incident port 2; regarding the reflective medium 102, the purpose in this example is mainly to enable the excitation light to be reflected multiple times inside the transparent substrate 101 to improve the efficiency of exciting the NV color center to generate feedback fluorescence. In a preferred scheme, the reflective medium 102 is designed in the form of a coating, and its material can be gold or silver, etc. In this example, the filter medium 103 is arranged on the second surface to filter out the feedback fluorescence. Taking the transparent substrate 101 as a rectangular thin block as an example, the generated feedback fluorescence can only be collected and obtained from the second surface (top surface). At the same time, the excitation light is also transmitted with the feedback fluorescence. In order to obtain high-purity feedback fluorescence, the filter medium 103 is designed on the second surface to only allow the feedback fluorescence to pass through it. In addition, considering that the excitation light will escape from the second surface and cause waste, in order to avoid this part of waste, in some scheme designs, the filter medium 103 is also used to reflect the excitation light. For this, different from the indiscriminate light reflection of the aforementioned reflective medium, it is required here that the filter medium 103 can transmit the feedback fluorescence and reflect the excitation light. A structure similar to a two-color filter can be selected to achieve the effect of transmitting red light and reflecting green light. In addition, considering that stray light may still exist after being filtered by the filter medium 103, a further scheme also includes a filter plate arranged on the filter medium, and the filter plate is used to filter out stray light.

[0022] In this example, the objective lens 3 is adapted to be arranged directly above the wide field sensing unit and is configured to be movable along the length direction of the wide field sensing unit to attach Figure 1For example, the direction of the arrow is the moving direction of the objective lens 3. The displacement driving component is not drawn in the figure, but it should be known that the displacement driving component can be various applicable devices in the prior art, such as a screw displacement driving component, a rack and pinion displacement driving component, a cylinder telescopic component, etc.; Regarding the positional relationship between the objective lens 3 and the wide-field sensing unit, it is based on the ability to clearly observe the feedback fluorescence on the top surface of the wide-field sensing unit.

[0023] In this example, the lever 4 is connected to the lower part of the objective lens 3. The shape of the lever 4 is not specifically limited, and it only needs to be able to move the reflective lens 5 to perform a set target action. Preferably, it is a straight lever.

[0024] In this example, a plurality of reflective lenses 5 are provided one by one in front of the light incident port 2. The reflective lenses 5 are configured as follows: when the lever 4 moves to the light incident port 2, the reflective lenses 5 are driven by the lever 4 to rotate to a set angle; when the lever 4 moves away from the light incident port 2, the reflective lenses 5 are restored to be parallel to the surface where the light incident port 2 is located, so as to be attached to the light incident port 2. Figure 1 and 4 For example, the wide field sensor unit is a rectangular parallelepiped structure, all light incident ports 2 are located on the front side of the rectangular parallelepiped structure, and the reflective lens 5 is installed at an appropriate distance in front of the front side. Regarding the reflective lens 5 and its function realization, in an exemplary solution, as shown in the attached Figure 4 As shown, it comprises a tube body 8, one side of the tube body 8 is provided with a through hole 81 facing the light incident port 2, the reflective lens 5 is rotatably arranged in the tube body 8, and a rotating shaft 82 is provided at the middle of the top of the reflective lens 5. The rotating shaft 82 passes through the top surface of the tube body 8 and is connected to a gear lever 83. A rotation return spring 84 is provided between the rotating shaft 82 and the tube body 8. When the lever 4 moves to the light incident port 2, the gear lever 83 is driven by the lever 4 to rotate a set angle. For the set angle, for ease of understanding, please refer to the attached Figure 3 The spatial light path 8 is located between the reflective lens 5 and the light incident port 2, and the lever 83 is perpendicular to the mirror surface of the reflective lens 5. When the lever 4 drives the reflective lens 5 to rotate 45° or a nearby angle, the excitation light transmitted in the spatial light path can enter the light incident port 2; in addition, in order to improve the stability and reliability of the operation of the lever 4, a slide groove 85 adapted to the moving trajectory of the lever 4 is provided on the top surface of the tube body 8, and the bottom of the lever 4 is slidably connected to the slide groove 85.

[0025] In this example, due to the design of the reflective lens 5, the incident excitation light must be in a certain orbit. Based on this, a spatial optical path 6 is set to limit it, which is used to transmit the excitation light. It is configured as follows: when any reflective lens 5 is rotated to a set angle, the excitation light transmitted in the spatial optical path 6 will be guided into the light incident port at the corresponding position through reflection.

[0026] In some preferred embodiments, as shown in the attached Figure 1 , 4As shown in FIG. 6 , the sensing structure further includes a bottom plate 10 for mounting the wide-field sensing unit. The bottom plate 10 is provided with a through groove 1001 corresponding to the bottom surface of the wide-field sensing unit. When in use, the wide-field sensing unit is installed in the through groove 1001, and the bottom surface is facing the object to be detected for detection. In order to facilitate the formation of the spatial optical path 6, the design of the bottom plate 10 is further explained here, as shown in FIG. Figure 6 As shown, a light path forming structure 11 can be set on the right side of the base plate 10, which can be a laser light source with a set light emission angle; or it can be a fiber coupler that inputs excitation light through an external optical fiber.

[0027] In some other schemes, the sensing structure further includes a wide-field camera 7, which is mounted on the objective lens 3 and is configured to move with the objective lens 3. In this example, the objective lens 3 is mounted on the wide-field sensing unit and is used to magnify the top surface of the wide-field sensing unit. In an exemplary scheme, the objective lens 3 is arranged at a fixed height above the wide-field sensing unit, and this height enables the top surface to be effectively focused and magnified by the objective lens 3, so that the wide-field camera 7 matched with the objective lens 3 can clearly capture the second surface magnified by the objective lens 3, wherein the wide-field camera 7 and the objective lens 3 can be connected integrally or non-integrally. In a preferred scheme, the wide-field camera 7 can be directly mounted on the objective lens 3 as a whole, as shown in the attached figure. Figure 1 and 4 As shown in FIG, the top of the objective lens 3 is directly connected to a wide-field camera 7, wherein the wide-field camera 7 may preferably be a CCD or a CMOS.

[0028] In addition, regarding the measurement application of NV color centers, the measurement method based on ODMR technology is popular. This method also uses microwaves to modulate NV color centers. Therefore, in some schemes, a microwave radiator 9 is also included. The microwave radiator 9 is used to radiate a microwave field to the transparent substrate 101. The design of the microwave radiator 9 is diverse. In the preferred scheme, as shown in the attached Figure 4 As shown, there is only one microwave radiator 9, which is arranged at the bottom of the objective lens 3 and moves with the objective lens 3. Figure 4 The microwave radiator 9 is a copper wire coil connected to the lever 4. <Example 2>

[0029] To facilitate understanding of the application scenarios of the sensing structure, this example proposes a nondestructive testing device for defect imaging detection of ferromagnetic objects, which applies the above sensing structure. In the preferred solution, a magnetizer is also configured to magnetize the object to be tested so that a leakage magnetic field is generated at the surface defects of the object for sensing by the sensing structure.

[0030] In the exemplary scheme, for ease of understanding, the following Figure 7For example, the sensing structure in the system is a microwave radiator 9, and the optical path forming structure 11 is a fiber coupler. Correspondingly, the system is also provided with a laser unit 12, a microwave unit 13 and a processor 14 (host). The excitation light output by the laser unit 12 is transmitted to the fiber coupler through the optical fiber, and then enters the spatial optical path. According to the detection requirements, the detection areas 1 in different areas are detected, and the displacement control device is started to move the objective lens 3 to the top of the corresponding detection area 1. At the same time, the lever 4 drives the reflective lens 5 at the corresponding position in the tube body 8 to rotate to a set angle, so that the excitation light in the spatial optical path is reflected to the light incident port 2 of the corresponding detection area 1. Synchronously, the microwave signal output by the microwave unit 13 enters the microwave radiator 9 through the radio frequency transmission line, and then forms a microwave field acting on the NV color center. The transparent substrate 1 senses the ferromagnetic object to be tested on the bottom side (at this time, it should be noted that the magnetizing accessory should be used to magnetize it first to generate a leakage magnetic field that characterizes the defect), and generates wide-field feedback fluorescence on the second surface. The wide-field camera 7 captures the fluorescence data of the second surface through the objective lens 3 and transmits it to the processor 14 for imaging processing.

[0031] Of course, the above system composition design is only one type of defect imaging system. For example, if the optical path forming structure 11 in the sensing structure is a laser light source, then correspondingly, the laser unit 12 in the above example is replaced by a light source power supply module.

[0032] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0033] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A sensing structure, characterized in that: Include: A wide-field sensing unit, comprising a plurality of detection areas containing NV color centers, the top surface of the detection area being a fluorescence output surface, a light incident port being arranged in the side surface of each detection area, and all the light incident ports being located on the same side, wherein the NV color center generates feedback fluorescence under the irradiation of excitation light of a specific wavelength; an objective lens adapted to be disposed directly above the wide field sensing unit and configured to be movable along the length direction of the wide field sensing unit; A lever connected to the lower side of the objective lens; A plurality of reflective lenses, which are arranged one by one in front of the light incident port, and the reflective lenses are configured such that: when the lever moves to the light incident port, the reflective lenses are driven by the lever to rotate to a set angle, and when the lever moves away from the light incident port, the reflective lenses return to being parallel to the surface where the light incident port is located; The spatial light path is used to transmit the excitation light, and is configured such that when any reflective lens is rotated to a set angle, the excitation light transmitted in the spatial light path is guided into a light incident port at a corresponding position by reflection.

2. The sensing structure according to claim 1, characterized in that: The wide-field sensing unit is formed by a row of transparent substrates connected to each other, the transparent substrates contain NV color centers, each of the transparent substrates includes a first surface, a second surface and a substrate peripheral side surface, the substrate peripheral side surface is provided with a light incident port, the excitation light enters from the light incident port, the substrate peripheral side surface other than the light incident port and the first surface are provided with reflective media, the second surface is a fluorescence output surface, and a filter medium for filtering out feedback fluorescence is provided thereon, and the objective lens is used to magnify the second surface.

3. The sensing structure according to claim 2, characterized in that: The filter medium is also used to reflect the excitation light.

4. The sensing structure according to claim 1, characterized in that: Also included is a wide-field camera that is adapted to be mounted with the objective lens and configured to move with the objective lens.

5. The sensing structure according to claim 1, characterized in that: It comprises a tube body, one side of which is provided with a through opening facing the light incident port, the reflective lens is rotatably arranged in the tube body, a rotating shaft is provided at the middle of the top of the reflective lens, the rotating shaft passes through the top surface of the tube body and is connected to a gear lever, a rotation return spring is provided between the rotating shaft and the tube body, wherein when the lever moves to the light incident port, the gear lever is driven by the lever to rotate to a set angle.

6. The sensing structure according to claim 5, characterized in that: The top surface of the tube body is provided with a slide groove matched with the moving track of the shifting rod, and the bottom of the shifting rod is slidably connected with the slide groove.

7. The sensing structure according to claim 1, characterized in that: The invention also comprises a microwave radiator, which is used for radiating a microwave field toward the transparent substrate.

8. The sensing structure according to claim 7, characterized in that: The number of the microwave radiator is one, and the microwave radiator is configured to move with the objective lens.

9. A nondestructive testing device, characterized in that: One or more sensing structures as claimed in any one of claims 1 to 8 are applied.

10. The nondestructive testing device according to claim 9, characterized in that: A magnetizer is also provided, and is used to magnetize the object to be tested so as to generate leakage magnetic fields at the surface defects of the object for sensing by the sensing structure.

Images