Sensing structure and nondestructive testing device

Abstract

The present invention relates to the field of quantum sensing technology, and the scheme is a sensing structure and a non-destructive testing device, wherein the sensing structure includes a wide-field sensing unit, an objective lens, a shift lever, a plurality of reflective lenses, and a spatial optical path; 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 shift lever enables the laser to accurately switch the incident position, thereby realizing segmented illumination of multiple detection areas by 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. They are formed when a nitrogen atom replaces a carbon atom in the diamond lattice, accompanied by a vacancy (a missing carbon atom) in the adjacent lattice. This structure causes changes in the surrounding electron state, thereby altering the diamond's absorption and emission properties in the visible spectrum, producing a specific color. NV color centers are typically excited using green excitation light at a wavelength of 532 nm, which in turn produces red feedback fluorescence. Changes in certain physical fields (such as magnetic fields and temperature) can cause specific changes in this red fluorescence, enabling sensing and measurement of specific physical fields.

[0003] For example, the Chinese invention patent with authorization announcement number CN117705932B proposes a quantum nondestructive sensor and a rail surface defect detection machine, which uses an optical fiber-diamond NV color center probe to perform nondestructive detection of surface defects in 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, which cannot quickly obtain the overall information of the defect area. In order to improve the rapid and comprehensive detection of defect 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:

[0006] A sensing structure comprising:

[0007] A wide-field sensing unit comprising a plurality of detection zones containing NV centers, the top surface of each detection zone being a fluorescence output surface, and a light inlet being provided on the side of each detection zone, with all light inlets being located on the same side. The NV centers generate feedback fluorescence when illuminated by excitation light of a specific wavelength;

[0008] an objective lens adapted to be disposed directly above the wide field sensing unit and configured to be movable along a length direction of the wide field sensing unit;

[0009] a lever connected to the lower side of the objective lens;

[0010] a plurality of reflective lenses, each correspondingly disposed in front of the light entrance, wherein the reflective lenses are configured such that when the lever is moved to the light entrance, the reflective lenses are driven by the lever to rotate to a set angle, and when the lever is moved away from the light entrance, the reflective lenses return to being parallel to the surface of the light entrance;

[0011] 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 the light incident port at the corresponding position by reflection.

[0012] 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, on which a filter medium for filtering out feedback fluorescence is provided, and the objective lens is used to magnify the second surface.

[0013] Furthermore, the filter medium is also used to reflect the excitation light.

[0014] Furthermore, it also includes a wide-field camera, which is adapted to be mounted on the objective lens and configured to move along with the objective lens.

[0015] Furthermore, it includes 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, and 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.

[0016] Furthermore, a sliding groove adapted to the moving track of the shifting rod is provided on the top surface of the tube body, and the bottom of the shifting rod is slidably connected to the sliding groove.

[0017] Furthermore, it also includes a microwave radiator, which is used to radiate a microwave field toward the transparent substrate.

[0018] Furthermore, there is one microwave radiator, which is configured to move with the objective lens.

[0019] On the other hand, the present invention also provides a non-destructive testing device, which applies one or more sensing structures as described above.

[0020] Furthermore, a magnetizer is provided for magnetizing the object to be measured so as to generate leakage magnetic fields at surface defects of the object for sensing by the sensing structure.

[0021] 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

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 Schematic diagram of the sensing structure in Example 1;

[0024] Figure 2 Schematic diagram of the transparent substrate and its accessories in Example 1;

[0025] Figure 3 for Figure 1 A in the middle is an enlarged schematic diagram;

[0026] Figure 4 Schematic diagram of the sensing structure with a tube body in Example 1;

[0027] Figure 5 is a cross-sectional view of the interior of the tube body in Example 1;

[0028] Figure 6 Schematic diagram of the structure of the bottom plate in Example 1;

[0029] Figure 7 Schematic diagram of the nondestructive testing device in Example 2. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0031] <Example 1>

[0032] 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.

[0033] In this example, the wide-field sensing unit includes several detection areas 1 containing NV color centers. The top surface of the detection area 1 is the fluorescence output surface. A light incident port 2 is provided on the side of each detection area 1, and all light incident ports 2 are on the same side. 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, Figure 2 As shown, the wide-field sensing unit is composed of a row of interconnected transparent substrates 101, each of which contains 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 provided on the substrate peripheral side surface, and excitation light enters through the light incident port 2. Reflective media 102 are provided on the substrate peripheral side surface and the first surface except for the light incident port 2. The second surface is a fluorescence output surface, on which a filter medium 103 for filtering out feedback fluorescence is provided. The objective lens 3 is used to magnify the second surface.

[0034] The transparent substrate 101 can be a diamond block uniformly distributed with NV color centers. However, due to the difficulty and cost of manufacturing large-scale diamond blocks, it is difficult to increase the overall size of the transparent substrate 101, making it difficult to obtain large-scale detection imaging effects. Considering this problem, another solution is to design a transparent substrate 101 with diamond particles uniformly distributed with ensemble NV color centers. In this solution, the transparent substrate 101 is made of a non-diamond transparent material, such as epoxy resin, and the diamond particles are nanometer-sized. In this example, the light incident port 2 is set on the side of the substrate, and the excitation light enters through 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 some excitation light and feedback fluorescence will leak out from this position and cause waste, to reduce waste, the area of ​​the light incident port 2 should be minimized while ensuring sufficient excitation light entry. In addition, to avoid light reflection waste caused by the excitation light entering the light incident port 2, in some preferred designs, an 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 peripheral side surfaces and the first surface of the substrate 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 parts except the light incident port 2; Regarding the reflective medium 102, the main purpose in this example is 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 solution, the reflective medium 102 is designed in the form of a coating, and its material can be gold or silver, etc. In this example, a filter medium 103 is disposed on the second surface to filter out feedback fluorescence. Taking the transparent substrate 101 as a thin rectangular block, the generated feedback fluorescence can only be collected and captured from the second surface (top surface). Simultaneously, excitation light is also transmitted along with the feedback fluorescence. To obtain high-purity feedback fluorescence, a filter medium 103 is designed on the second surface to allow only the feedback fluorescence to pass through it. Furthermore, considering that excitation light may escape from the second surface and cause waste, some designs also utilize the filter medium 103 to reflect the excitation light. Unlike the previously described reflective medium, which reflects light indiscriminately, the filter medium 103 is required to transmit the feedback fluorescence while reflecting the excitation light. A structure similar to a dichroic filter can be used, which can achieve the effect of transmitting red light and reflecting green light. Furthermore, considering that stray light may still be present after being filtered by the filter medium 103, further solutions include a filter disposed on the filter medium to filter out stray light.

[0035] 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 member is not drawn in the figure, but it should be known that the displacement driving member can be various applicable devices in the prior art, such as a screw displacement driving member, a rack and pinion displacement driving member, a cylinder telescopic member, etc.; Regarding the positional relationship between the objective lens 3 and the wide-field sensing unit, it shall be based on the ability to clearly observe the feedback fluorescence on the top surface of the wide-field sensing unit.

[0036] In this example, the lever 4 is connected to the lower side of the objective lens 3. The shape of the lever 4 is not particularly limited, as long as it can move the reflective lens 5 to perform a set target action. Preferably, it is a straight lever.

[0037] In this example, there are multiple reflective lenses 5, which are arranged 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 return to being parallel to the surface where the light incident port 2 is located, so as to be attached. Figure 1 and 4 For example, the wide field sensing 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, 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 opening 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 to a set angle. Regarding 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 gear 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, the top surface of the tube body 8 is provided with a slide groove 85 that is compatible with the moving trajectory of the lever 4, and the bottom of the lever 4 is slidably connected to the slide groove 85.

[0038] 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.

[0039] In some preferred embodiments, as shown in the attached Figure 1 、 4As shown in FIG6 , the sensing structure further includes a base plate 10 for mounting the wide-field sensing unit. The base plate 10 has a through slot 1001 on the bottom surface corresponding to the wide-field sensing unit. When in use, the wide-field sensing unit is mounted in the through slot 1001 with the bottom surface facing the object to be detected. To facilitate the formation of the spatial optical path 6 , the design of the base plate 10 is further explained here. 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 a fiber coupler that inputs excitation light through an external optical fiber.

[0040] In some other schemes, the sensing structure further includes a wide-field camera 7, which is adapted to be installed with the objective lens 3 and is configured to move with the objective lens 3. In this example, the objective lens 3 is adapted to 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 set at a fixed height above the wide-field sensing unit. This height enables the top surface to be effectively focused and magnified by the objective lens 3, so that the wide-field camera 7 adapted to 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 connected to the objective lens 3 and installed 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 the wide-field camera 7, wherein the wide-field camera 7 can preferably be a CCD or a CMOS.

[0041] 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 solutions, 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 solution, as shown in the attached Figure 4 As shown, there is only one microwave radiator 9, which is located 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 shift rod 4.

[0042] <Example 2>

[0043] To facilitate understanding of the application scenarios of the sensing structure, this example proposes a nondestructive testing device for imaging defect detection of ferromagnetic objects, employing the aforementioned sensing structure. In a preferred embodiment, a magnetizer is also provided to magnetize the object to be tested, thereby generating a leakage magnetic field at the surface defects that is sensed by the sensing structure.

[0044] In the exemplary embodiment, for ease of understanding, Figure 7For example, the sensing structure in this system utilizes a microwave radiator 9, and the optical path forming structure 11 is a fiber coupler. Accordingly, the system further comprises a laser unit 12, a microwave unit 13, and a processor 14 (host). The excitation light output by the laser unit 12 is transmitted via an optical fiber to the fiber coupler and then enters the spatial optical path. Based on detection requirements, different detection zones 1 are inspected. The displacement control device is activated, moving the objective lens 3 above the corresponding detection zone 1. Simultaneously, the lever 4 rotates the reflective lens 5 at the corresponding position within the tube 8 to a set angle, causing the excitation light in the spatial optical path to be reflected into the light inlet 2 of the corresponding detection zone 1. Simultaneously, the microwave signal output by the microwave unit 13 enters the microwave radiator 9 via an RF transmission line, thereby forming a microwave field that acts on the NV color center. The transparent substrate 1 senses the ferromagnetic object under test (note that the substrate should be magnetized using a magnetizing accessory 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.

[0045] 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.

[0046] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0047] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. 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 zones containing NV centers, the top surface of each detection zone being a fluorescence output surface, and a light inlet being provided on the side of each detection zone, with all light inlets being located on the same side. The NV centers generate feedback fluorescence when illuminated by 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 a length direction of the wide field sensing unit; a lever connected to the lower side of the objective lens; a plurality of reflective lenses, each correspondingly disposed in front of the light entrance, wherein the reflective lenses are configured such that when the lever is moved to the light entrance, the reflective lenses are driven by the lever to rotate to a set angle, and when the lever is moved away from the light entrance, the reflective lenses return to being parallel to the surface of the light entrance; 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 the light incident port at the corresponding position by reflection.

2. The sensing structure according to claim 1, characterized in that The wide-field sensing unit is composed of a row of transparent substrates connected to each other, each of which contains NV color centers. Each of the transparent substrates includes a first surface, a second surface, and a substrate peripheral side surface. A light incident port is provided on the substrate peripheral side surface, and excitation light enters from the light incident port. Reflective media are provided on the substrate peripheral side surface and the first surface except the light incident port. The second surface is a fluorescence output surface, on which a filter medium for filtering out feedback fluorescence is provided. 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 adapted to be mounted on the objective lens and configured to move along with the objective lens.

5. The sensing structure according to claim 1, characterized in that: The utility model 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 part 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, and 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 sliding groove adapted to the moving track of the shifting rod, and the bottom of the shifting rod is slidably connected to the sliding groove.

7. The sensing structure according to claim 2, characterized in that: The invention also comprises a microwave radiator, which is used to radiate a microwave field toward the transparent substrate.

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

9. A nondestructive testing device, characterized in that: One or more sensing structures according to 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, which is used to magnetize the object to be measured so as to generate leakage magnetic fields at defects on its surface for sensing by the sensing structure.

Images