Array sensing unit and quantum detection probe

Abstract

The invention relates to the technical field of quantum sensing, and provides an array sensing unit and a quantum detection probe wherein the quantum sensing unit comprises a transparent substrate, an entrance port, a reflective medium and a filtering medium; according to the array sensing unit, wide-field measurement can be achieved, overall information of a defect area can be obtained, meanwhile, the array type measurement structure can extend the measurement range in the longitudinal direction, and it can be guaranteed that the NV color center is fully irradiated by independent lighting of each detection area; according to the quantum detection probe disclosed by the invention, the adaptive combination of the wide-field camera, the objective lens and the array sensing unit is used, so that fluorescent light in extremely small pixels can be distinguished and detected, and the detection resolution can be improved.

Description

Technical Field

[0001] The present invention relates to the field of quantum sensing technology, and in particular to an array sensing unit and a quantum detection probe. 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 an array sensor unit and a quantum detection probe to solve the problems existing in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions: An array sensor unit comprises a plurality of sensor units, wherein the sensor unit comprises a transparent substrate, an incident port, a reflective medium and a filter medium, wherein the transparent substrate comprises a first surface, a second surface and a substrate peripheral side surface, and contains an NV color center that generates feedback fluorescence under the irradiation of excitation light, the incident port is arranged on the substrate peripheral side surface, and the excitation light enters from the incident port, the reflective medium is arranged on the substrate peripheral side surface and the first surface except the incident port; the filter medium is arranged on the second surface, and is used to filter out the feedback fluorescence; All the sensing units are arranged with the first surface facing downward and the second surface facing upward, and the peripheral sides of the bases of adjacent sensing units are connected to each other so that all the sensing units form an integral row, and all the incident ports are kept facing the same side.

[0006] In a further solution, the incident port is provided with an anti-reflection film.

[0007] In a further embodiment, the filter medium is also used to reflect the excitation light.

[0008] In a further solution, the sensing unit further includes a filter disposed on the filter medium, and the filter is used to filter out stray light.

[0009] In a further embodiment, the transparent substrate as a whole is a diamond block with NV color centers evenly distributed inside, or the transparent substrate is evenly distributed with diamond particles containing ensemble NV color centers.

[0010] On the other hand, the present invention also provides a quantum detection probe, which uses the array sensor unit as described in any of the previous items, and also includes an objective lens adapted to be arranged directly above the array sensor unit, and the objective lens is configured to be movable along the length direction of the array sensor unit.

[0011] In a further solution, it also includes a plurality of optical fiber couplers, which correspond one to one in front of the incident port and are configured to transmit the light in the optical fiber connected thereto into the incident port.

[0012] In a further solution, it further comprises a plurality of excitation light sources, which correspond one to one in front of the incident ports and are configured to emit excitation light into the corresponding incident ports.

[0013] In a further embodiment, a microwave radiator is also included, and the microwave radiator is used to radiate a microwave field toward the transparent substrate.

[0014] In a further solution, a wide-field camera is also included, which is used to obtain the image magnified by the objective lens.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The array sensing unit in the present invention can realize wide-field measurement and obtain the overall information of the defect area. At the same time, the array measurement structure can extend the measurement range in the longitudinal direction, and each detection area is independently illuminated to ensure that the NV color center is fully illuminated.

[0016] 2. The quantum detection probe in the present invention uses a combination of a wide-field camera, an objective lens and an array sensor unit, which can distinguish and detect fluorescence within extremely small pixels and improve the detection resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] Figure 1 is a schematic diagram of the structure of the array sensor unit in Example 1; Figure 2 This is a structural exploded view of a single sensor unit in Example 1; Figure 3 This is a structural exploded diagram of the quantum detection probe in Example 2; Figure 4 This is a schematic diagram of the structure of a quantum detection probe containing an optical fiber coupler in Example 2; Figure 5 for Figure 4 The enlarged schematic diagram at A in the middle; Figure 6 is a schematic structural diagram of a base plate containing a light source in Example 2; Figure 7 Schematic diagram of the defect imaging system in Example 2. DETAILED DESCRIPTION

[0019] 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

[0020] See attached Figure 1 and 2 This example introduces an array sensor unit, comprising a plurality of sensor units 1, wherein the sensor unit comprises a transparent substrate 101, an incident port 102, a reflective medium 103 and a filter medium 104, wherein the transparent substrate 101 comprises a first surface (i.e., a bottom surface), a second surface (i.e., a top surface) and a substrate peripheral side surface, which contains an NV color center that generates feedback fluorescence under the irradiation of excitation light, the incident port 102 is arranged on the substrate peripheral side surface, and the excitation light enters from the incident port, the reflective medium 103 is arranged on the substrate peripheral side surface and the first surface except the incident port 102; the filter medium 104 is arranged on the second surface for filtering out the feedback fluorescence; wherein all the sensor units 1 are arranged with the first surface facing downward and the second surface facing upward, the substrate peripheral side surfaces of adjacent sensor units 1 are connected to each other so that all the sensor units 1 form a whole row, and all the incident ports 102 remain facing the same side.

[0021] In this example, 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 increase, and it is difficult to obtain a larger-size detection imaging effect. Taking this problem into consideration, another scheme is to design the transparent substrate 101 to have diamond particles containing ensemble NV color centers evenly distributed inside. In this scheme, the transparent substrate 101 is made of a non-diamond transparent material, such as epoxy resin, and the size of the diamond particles is nanometer-level.

[0022] In this example, the incident port 102 is arranged on the side surface of the substrate, and the excitation light enters from the incident port 102; taking the transparent substrate 101 as a rectangular thin block as an example, the incident port 102 is arranged on its side, and 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 incident port 102 should be minimized while ensuring that the excitation light can fully enter; in addition, in order to avoid the waste of light reflection generated when the excitation light enters the incident port 102, in some preferred designs, a layer of anti-reflection film is also designed on the surface of the incident port 102.

[0023] In this example, the reflective medium 103 is arranged on the surrounding side surfaces of the substrate and the first surface except the incident port 102; taking the transparent substrate 101 as a rectangular thin block as an example, the reflective medium 103 is arranged on the bottom surface of the rectangular thin block and all side portions except the incident port 102; regarding the reflective medium 103, 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 solution, the reflective medium 103 is designed in the form of a coating, and its material can be gold or silver, etc.

[0024] In this example, the filter medium 104 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), and the excitation light is also transmitted with the feedback fluorescence. In order to obtain high-purity feedback fluorescence, the filter medium 104 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 104 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 104 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 104, a further scheme also includes a filter 105 arranged on the filter medium, and the filter 105 is used to filter out stray light.

[0025] In this example, the connection between adjacent sensor units 1 can be achieved through optical glue. In addition, although the lead-out array sensor unit in this example is composed of multiple sensor units 1 connected to each other, in fact, in some schemes, the filter medium 104 can also be an integrally formed structure design, and there is no connected end surface. That is to say, in actual production, a sensor unit without a filter medium 104 can be made first, and after several such sensor units are connected into one, an integral filter medium 104 can be designed on the integral structure. Example 2

[0026] See attached Figure 3 This embodiment is based on the array sensor unit proposed in Example 1, and proposes a quantum detection probe, which, in addition to applying the array sensor unit as described above, also includes an objective lens 2 adapted to be arranged directly above the array sensor unit, and the objective lens 2 is configured to be movable along the length direction of the array sensor unit. The objective lens 2 is adapted to the array sensor unit, and is used to magnify the top surface of the array sensor unit. In an exemplary scheme, the objective lens 2 is arranged at a fixed height above the array sensor unit, and this height enables the top surface to be effectively focused and magnified by the objective lens 2, so that the wide-field camera adapted to the objective lens 2 can clearly capture the second surface magnified by the objective lens 2, wherein the wide-field camera and the objective lens can be connected in an integral or non-integrated manner. In a preferred scheme, the wide-field camera can be directly connected to the objective lens 6 and installed as a whole, as shown in the attached figure. Figure 3 As shown in FIG, the top of the objective lens 2 is directly connected to a wide-field camera 4, wherein the wide-field camera 4 may preferably be a CCD or a CMOS.

[0027] In some preferred embodiments, as shown in the attached Figure 3 As shown, the quantum detection probe also includes a base plate 5 for installing the quantum sensing unit. The base plate 5 is provided with a through groove 501 corresponding to the bottom surface of the array sensing unit. When in use, the array sensing unit is installed in the through groove 501, and the bottom surface is facing the object to be detected for detection.

[0028] In this embodiment, based on the design of the incident port 102, the incident area of ​​the excitation light is limited. Therefore, in order to maintain accurate incident of the excitation light, in some preferred embodiments, as shown in the attached Figure 3 As shown, a light emitting component 6 is fixedly designed in the incident area, which can be a laser light source directly, and its laser emitting port is designed to be aligned with the incident port 102, or it can be a fiber coupler, and its side center is designed to be aligned with the incident port 102. Based on the design of the above-mentioned bottom plate 5, in one solution, see the attached Figure 4 and 5, a fiber coupler 601 is arranged on the bottom plate 5 at a position corresponding to the incident port 102, and the fiber coupler 601 is connected to the transmission fiber 7 for the external excitation light, and the excitation light enters the incident port 102 from the fiber coupler 601; in addition, considering the problem of optical fiber transmission loss, in another solution, see the attached Figure 6 A light source 602 (replacing the optical fiber coupler 601) is arranged on the bottom plate 5 at a position corresponding to the incident port 102. By powering, the light source 602 directly outputs excitation light to the incident port 102. In this design, the bottom plate 5 can be designed as a circuit board structure, and the light source 602 is installed and connected through electrodes and conductive structures.

[0029] 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 is also included. The microwave radiator is used to radiate a microwave field to the transparent substrate. The design of the microwave radiator is diverse. In an example scheme, as shown in the attached Figure 3 and 4 As shown, a microwave radiator 3 is provided at the bottom of the objective lens 2, and moves along with the objective lens 2. The microwave radiator 3 in the figure is a copper wire coil.

[0030] To facilitate understanding of the application scenarios of quantum detection probes, this example proposes a defect imaging system for defect imaging detection of ferromagnetic objects, which uses the wide-field detection probe described above.

[0031] In the exemplary scheme, for ease of understanding, the following Figure 7 For example, the quantum detection probe in the system is a probe design that uses a light source 602 and a microwave radiator 3. Correspondingly, the system is also provided with a power supply control unit 8, a microwave unit 9 and a processor 10 (host). The power supply control unit 8 is used to control the operation of each light source 602. The microwave signal output by the microwave unit 19 enters the microwave radiator 3 through the radio frequency transmission line, and then forms a microwave field that acts on the NV color center. The transparent substrate 101 senses the ferromagnetic object to be tested on the bottom side (in some cases, it can be magnetized first using a magnetizing accessory to generate a leakage magnetic field that characterizes the defects) and generates wide-field feedback fluorescence on the second side. The wide-field camera captures the fluorescence data of the second side through the object 6 and transmits it to the processor 13 for imaging processing.

[0032] Of course, the above system composition design is only one type of defect imaging system. For example, if the wide-field detection probe is a probe design using a fiber coupler 601, then correspondingly, the power supply control unit 8 in the above example is replaced by a laser unit.

[0033] 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.

[0034] 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. An array sensor unit, characterized in that: The sensor unit comprises a plurality of sensing units, wherein the sensing unit comprises a transparent substrate, an incident port, a reflective medium and a filter medium, wherein the transparent substrate comprises a first surface, a second surface and a substrate peripheral side surface, and contains an NV color center that generates feedback fluorescence under the irradiation of excitation light, the incident port is arranged on the substrate peripheral side surface, and the excitation light enters from the incident port, the reflective medium is arranged on the substrate peripheral side surface except the incident port and the first surface; the filter medium is arranged on the second surface, and is used to filter out the feedback fluorescence; All the sensing units are arranged with the first surface facing downward and the second surface facing upward, and the peripheral sides of the bases of adjacent sensing units are connected to each other so that all the sensing units form an integral row, and all the incident ports are kept facing the same side.

2. The array sensor unit according to claim 1, characterized in that: The incident port is provided with an anti-reflection film.

3. The array sensor unit according to claim 1, characterized in that: The filter medium is also used to reflect the excitation light.

4. The array sensor unit according to claim 1, characterized in that: The sensing unit further comprises a filter plate arranged on the filter medium, and the filter plate is used for filtering out stray light.

5. The array sensor unit according to claim 1, characterized in that: The transparent substrate as a whole is a diamond block with NV color centers evenly distributed inside, or the transparent substrate is evenly distributed with diamond particles containing ensemble NV color centers.

6. A quantum detection probe, characterized in that: The array sensor unit according to any one of claims 1 to 5 is used, and further comprises an objective lens adapted to be arranged directly above the array sensor unit, wherein the objective lens is configured to be movable along the length direction of the array sensor unit.

7. The quantum detection probe according to claim 6, characterized in that: It also comprises a plurality of optical fiber couplers, which correspond to the front of the incident port one by one and are configured to transmit the light in the optical fiber connected thereto into the incident port.

8. The quantum detection probe according to claim 6, characterized in that: It also includes a plurality of excitation light sources, which correspond to the front of the incident ports one by one and are configured to emit excitation light into the corresponding incident ports.

9. The quantum detection probe according to claim 6, characterized in that: The invention also comprises a microwave radiator, which is used for radiating a microwave field toward the transparent substrate.

10. The quantum detection probe according to claim 6, characterized in that: The device also comprises a wide-field camera, which is used for acquiring the image magnified by the objective lens.

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