An opto-mechatronics sensor chip and its application

Abstract

This invention discloses an opto-mechatronics integrated sensing chip and its application. The chip includes a sensing element substrate, an optical channel substrate, and a cover plate. The sensing element substrate integrates a microwave antenna, a first light source, a second light source, and a diamond NV color center. The optical channel substrate integrates a first reflector, and the first reflector and the mirrored surfaces on both sides of the diamond NV color center form an optical resonant loop. The cover plate integrates a first photodetector, a second photodetector, and a third photodetector, which are used to detect fluorescence, excitation light, and absorption light, respectively. This chip can be used as a sensing element in a quantum current transformer. This invention can improve light intensity through the resonant loop, and has the advantages of simple structure, easy integration and miniaturization. It can realize the switching between two measurement principles, and has the advantages of simple structure and simple manufacturing process, enabling miniaturization.

Description

Technical Field

[0001] This invention relates to the field of quantum sensing chips, specifically to an opto-mechatronics integrated sensing chip and its applications. Background Technology

[0002] Currently, the principle of traditional magnetic sensors based on diamond NV centers is a precise cyclic process based on optical detection of magnetic resonance. It begins with optical initialization: using a green laser to efficiently polarize and prepare the electron spins of the diamond NV centers into the ground state energy level |m s =0 In this state, the fluorescence intensity is strongest. When the magnetic field to be measured is present, according to the Zeeman effect, the diamond NV color center will undergo energy level transitions due to the external magnetic field (i.e., |m... s =0 → |m s = 1 Next comes magnetic resonance manipulation: a frequency-scanning microwave field is applied to the diamond NV color center, and the microwave frequency is adjusted to match the energy level transition frequency (i.e., |m) that shifts due to the external magnetic field. s =0 → |m s = 1 At precise resonance, the spin population is altered. Then comes the spin state readout: due to being in |m s = 1 The color center of the spin state, under laser excitation, undergoes a significant decrease in fluorescence intensity via intersystem crossing pathways. Therefore, this spin state change is converted into a measurable attenuation of the fluorescence signal. Finally, in the data processing stage, by scanning the microwave frequency and recording the corresponding fluorescence intensity, an ODMR line with a characteristic "depression" is obtained. The shift Δν of the resonance frequency corresponding to this depression relative to the zero-field splitting value (2.87 GHz) is proportional to the magnetic field component B∥ along the NV axis. By accurately measuring Δν, nanoscale, highly sensitive quantitative detection of the magnetic field under test can be achieved.

[0003] Besides the magnetic field measurement technique of exciting the fluorescence of diamond NV color centers with green lasers, existing technologies also utilize the magnetic field of |m s = 1 The NV center in the ground state exhibits selective absorption of 1042 nm infrared probe light. Magnetic field measurement systems, such as those described in patent CN116299098A, utilize this technology for magnetic field measurement. The specific principle of diamond NV center magnetometry based on selective infrared absorption is as follows: 532 nm pump light is used to spin-polarize the electrons of the NV center to the ground state |ms =0 Energy level, then a swept microwave field is applied; when the microwave frequency is shifted by |m| due to the Zeeman effect s =0 →|m s = 1 At the resonance of the energy level transition frequency, the spin population changes, resulting in a state at |m s = 1 The NV color center in the state selectively absorbs 1042 nm infrared probe light; by monitoring the resonant attenuation of the infrared transmitted light intensity and calculating the corresponding microwave frequency shift, the external magnetic field can be quantitatively detected based on the microwave frequency shift. This prior art patent, with publication number CN116299098A, differs from traditional technologies that detect the weak fluorescence generated by the stimulated NV color center; it primarily detects changes in the intensity of infrared transmitted light.

[0004] Existing technologies for magnetic field measurement using green laser-excited diamond NV centers for fluorescence suffer from several drawbacks. Firstly, the fluorescence intensity emitted by the NV centers is low and its variation with the magnetic field is minimal, leading to measurement difficulties. Secondly, existing technologies, such as the magnetic measurement system constructed using the selective absorption of infrared probe light by NV centers as described in patent CN116299098A, suffer from poor intrinsic signal contrast (at room temperature, the absorption contrast of NV centers for 1042 nm infrared light (~1%) is far lower than the contrast of fluorescence detection methods (~30%)), resulting in high measurement difficulty and power consumption.

[0005] Therefore, existing technologies, whether based on green laser-induced fluorescence of diamond NV centers or on selective absorption of infrared probe light by NV centers, all suffer from the problem of high measurement difficulty. Summary of the Invention

[0006] This invention provides an opto-mechatronics integrated sensing chip and its application to solve the problem of high measurement difficulty in existing magnetic field measurement technology based on diamond NV color centers.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An opto-mechatronics integrated sensing chip, comprising: The sensing element substrate (2) integrates a microwave antenna (23), a first light source (24), a second light source (25), and a diamond NV color center (22). The diamond NV color center (22) has a trapezoidal structure and is attached to the microwave antenna (23). The two sides of the diamond NV color center (22) are respectively set as mirrored surfaces. The first light source (24) is used to output excitation light, and the second light source (25) is used to output absorption light. The output light of the first light source (24) and the second light source (25) is respectively incident on the mirrored surfaces on both sides of the diamond NV color center (22). The optical channel substrate (3) integrates a first reflector (36); one side of the sensing element substrate (2) is connected to one side of the optical channel substrate (3), so that the first reflector (36) faces the trapezoidal bottom surface of the diamond NV color center (22); the first reflector (36) and the mirrored surfaces on both sides of the diamond NV color center (22) form an optical resonant loop, and the excitation light and absorption light can be trapped and cycled multiple times in the optical resonant loop and output through the first reflector (36). During the cycle, the excitation light and absorption light pass through the diamond NV color center (22). The sealing plate (4) integrates a first photodetector (42), a second photodetector (43), and a third photodetector (44). One side of the sealing plate (4) is connected to the other side of the light channel substrate (3). The first photodetector (42) is used to detect the fluorescence generated by the diamond NV color center (22) when it is excited. The second photodetector (43) is used to detect the absorbed light output through the first reflector (36). The third photodetector (44) is used to detect the excitation light output through the first reflector (36).

[0008] Furthermore, the excitation light output by the first light source (24) is green light.

[0009] Furthermore, the absorbed light output by the second light source (25) is infrared light.

[0010] Furthermore, the sensing element substrate (2) also integrates two heat sinks, with the first light source (24) and the second light source (25) respectively disposed on the two heat sinks.

[0011] Furthermore, the optical channel substrate (3) also integrates an actuator (361) to adjust the position of the first reflector (36).

[0012] Furthermore, in the sealing plate (4), a filter is provided at the position corresponding to the detection surface of at least one photodetector.

[0013] Furthermore, the sensing element substrate (2) is bonded to the optical channel substrate (3), and the optical channel substrate (3) is bonded to the cover plate (4).

[0014] Furthermore, the sensing element substrate (2) also integrates two guide mirrors (27). When one side of the sensing element substrate (2) is connected to one side of the optical channel substrate (3), one side of the first reflector (36) faces the trapezoidal bottom surface facing the diamond NV color center (22), and the other side of the first reflector (36) faces the two guide mirrors (27). One guide mirror (27) is used to reflect the excitation light output by the first reflector (36), and the other guide mirror is used to reflect the absorption light output by the first reflector (36). The second photodetector (43) detects the absorbed light reflected by one of the guide mirrors, and the third photodetector (44) detects the excitation light reflected by the other guide mirror.

[0015] Furthermore, the guide mirror (27) is a prism, and a reflective film is coated on the reflective surface of the guide mirror (27).

[0016] An application of the aforementioned opto-mechatronics integrated sensing chip as a sensing element in a quantum current transformer.

[0017] Compared with the prior art, the advantages of the present invention are: 1. This invention can improve light intensity through a resonant loop, namely, by enhancing the resonance of the excitation light and the resonance of the absorption light. When the excitation light resonance is enhanced, the excitation effect of green light on the diamond NV color center can be improved (enhancing photofluorescence); when the absorption light resonance is enhanced, the contrast of the intrinsic signal of the absorption light can be improved, and the absorption effect of the diamond NV color center on infrared absorption light can be enhanced.

[0018] 2. The resonant loop in this invention is constructed from the mirrored surfaces on both sides of the diamond NV color center and the first reflecting mirror. Therefore, the structure is simple, requires fewer optical components, and is easy to integrate and miniaturize. Furthermore, since this invention uses an optical resonant loop to enhance the resonance of the excitation and absorption light, it can enhance the excitation effect of the diamond NV color center and improve the contrast of the intrinsic signal of the absorption light without using a high-power laser as a light source, thus possessing the advantage of low energy consumption.

[0019] 3. This invention can switch between two measurement principles. When only the first light source is working, it realizes the magnetic measurement method based on the fluorescence generated by the stimulated diamond NV color center. When only the second light source is working, it realizes the magnetic measurement method based on the selective absorption of light by the diamond NV color center. Furthermore, when the first light source and the second light source are working simultaneously, both magnetic measurement methods can be realized at the same time. Therefore, it has rich functions, strong verification, and can meet the needs of non-measuring. 4. The present invention optimizes the structural design, thus the structure is simple, the manufacturing process is simple, and the size can be miniaturized, making it easy to integrate into the detection system.

[0020] 5. This invention is well-suited for power grid current measurement and can be used as a sensing element in existing electronic current transformers. Attached Figure Description

[0021] Figure 1 This is an overall structural diagram of an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the substrate structure of the sensing element in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the optical channel substrate structure according to an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the combined structure of the sensing element substrate and the optical channel substrate according to an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the sealing plate according to an embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of the device positions on the optical resonant loop in an embodiment of the present invention. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] like Figure 1 As shown, this embodiment discloses an opto-mechatronics integrated sensing chip, which has a stacked structure, consisting of a carrier PCB1, a sensing element substrate 2, an optical channel substrate 3, and a cover plate 4 from bottom to top.

[0029] The carrier PCB1 is a carrier printed circuit board that provides mechanical support and external electrical connections for the entire device.

[0030] like Figure 2 As shown, the sensing element substrate 2 includes a first wafer 21. A microwave antenna 23 is etched on the top surface of the first wafer 21, and a trapezoidal diamond NV color center 22 (a block diamond containing ensemble NV color centers) is attached to the microwave antenna 23. The trapezoidal top surface of the diamond NV color center 22 faces forward and the trapezoidal bottom surface faces backward. The left and right side slopes of the diamond NV color center 22 are mirrored.

[0031] On the top surface of the first wafer 21, heat sink windows are formed on the left and right sides in front of the diamond NV color center 22, and a heat sink 26 is mounted in each heat sink window. The heat sink 26 on the right side is equipped with a first light source 24, and the heat sink 26 on the left side is equipped with a second light source 25. The first light source 24 outputs excitation light (green light, such as around 532nm), and the second light source 26 outputs absorption light (infrared light, wavelength 1042nm). The output light from the first light source 24 and the second light source 25 are respectively incident on the mirrored surfaces on both sides of the diamond NV color center 22.

[0032] Two guide mirrors 27 are mounted on the top surface of the first wafer 21 at the far rear end of the trapezoidal bottom surface of the diamond NV color center 22. Both guide mirrors 27 face the bottom edge of the diamond NV color center 22 trapezoid and are inclined in the vertical plane. The guide mirrors 27 are triangular prisms with a reflective coating on their reflective surfaces.

[0033] In the sensing element substrate 2, the bottom surface of the first wafer 21 is bonded to the top surface of the carrier PCB1 through a eutectic bonding process.

[0034] like Figure 3 As shown, the optical channel substrate 3 includes a second wafer 31, in which two light source windows 33, a color center window 32, a reflector window 34, and a guide mirror window 35 are formed. All three windows vertically penetrate the optical channel substrate 3. The two light source windows 33 are located to the left and right of the color center window 32, respectively, and are connected to the left and right sides of the color center window 32. The reflector window 34 is disposed adjacent to the rear side of the color center window 32, and its length in the left-right direction is greater than that of the color center window 32. The reflector window 34 is connected to the rear side of the color center window 32. The guide mirror window 35 is disposed adjacent to the rear side of the reflector window 34 and is connected to the rear side of the reflector window 34. A first reflector 36 is mounted in the reflector window 34. An actuator 361 (such as a piezoelectric actuator) is also provided in the reflector window 34. The actuator 361 is in contact with the first reflector 36, and the position of the first reflector 36 is changed by the actuator 361 acting on the first reflector 36.

[0035] like Figure 4As shown, in the optical channel substrate 3, the bottom surface of the second wafer 31 is bonded to the top surface of the first wafer 21 in the sensing element substrate 2 via a eutectic bonding process. This places the first light source 24 in the right-side light source window 33, the second light source 25 in the left-side light source window 33, the diamond NV color center 22 in the color center window 32, and the two guide mirrors 27 in the guide mirror window 35. After bonding, the front side of the first reflector 36 faces the trapezoidal bottom surface of the diamond NV color center 22, and the rear side of the first reflector 36 faces the two guide mirrors 27.

[0036] like Figure 6 As shown, the first reflecting mirror 36 and the mirrored surfaces on both sides of the diamond NV color center 22 form an optical resonant loop. Both the excitation light and the absorption light can be trapped and circulated multiple times in the optical resonant loop and output through the first reflecting mirror 36. During the circulation, both the excitation light and the absorption light pass through the diamond NV color center 22. The excitation light excites the diamond NV color center 22 to produce fluorescence, and the absorption light is selectively absorbed by the diamond NV color center 22. The excitation light and the absorption light output by the first reflecting mirror 36 are reflected by the two guide mirrors 27 respectively.

[0037] The positional relationship between the first reflecting mirror 36 and the two mirrored surfaces of the diamond NV color center 22 satisfies the formation of an optical resonant loop. By trapping light in the optical resonant loop and cycling it hundreds or thousands of times, the excitation and absorption effect of the diamond NV color center 22 is improved, thereby amplifying the weak magnetic signal to a level that can be clearly detected.

[0038] like Figure 5 As shown, the cover plate 4 includes a third wafer 41, and three sensor windows 45 are formed on the bottom surface of the third wafer 41, arranged in a triangular pattern. A first photodetector 42 is installed in the foremost sensor window 45, and a second photodetector 43 and a third photodetector 44 are installed in the two rear sensor windows, respectively. Furthermore, filters are respectively placed on the detection surfaces of the photodetectors installed in the three sensor windows 45 to filter out stray light.

[0039] In the sealing plate 4, the bottom surface of the third wafer 41 is bonded to the top surface of the second wafer 31 in the optical channel substrate 3 via a eutectic bonding process. After bonding, the sensor window of the first photodetector 42 is opposite to the color center window 32 in the optical channel substrate 3, so that the first photodetector 42 faces the diamond NV color center 22. The sensor windows of the second photodetector 43 and the third photodetector 44 are opposite to the guide mirror window 35 in the optical channel substrate 3, so that the second photodetector 43 and the third photodetector 44 face the two guide mirrors 27 respectively. One guide mirror 27 reflects the absorbed signal light upward to the second photodetector 43, and the other guide mirror reflects the excitation signal light upward to the third photodetector 44. The excitation light and the absorbed light are guided upward through the two guide mirrors. Thus, the first photodetector 42 detects the fluorescence generated by the excitation of the diamond NV color center 22, the second photodetector 43 detects the absorbed light reflected by one of the guide mirrors, and the third photodetector 44 detects the excitation light reflected by the other guide mirror.

[0040] like Figure 6 As shown, in this embodiment, the first light source 24 emits excitation light, and the second light source 26 emits absorption light. The excitation and absorption light are respectively incident on the mirrored surfaces on both sides of the diamond NV color center 22 into the optical resonant loop for enhanced resonance. The excitation and absorption light are then output through the first reflecting mirror 36, and their directions are changed by their respective guide mirrors 24, propagating towards the sealing plate. During this resonance process, both the excitation and absorption light pass through the diamond NV color center 22 and are reflected by the mirrored surfaces on both sides of the diamond NV color center 22. To meet the resonance conditions, the position of the first reflecting mirror 36 is adjusted by an actuator 36, thereby changing the optical path length and achieving enhanced resonance for both types of light. The first reflecting mirror 36 is designed to achieve efficient reflection and minimal transmission, thus achieving both efficient resonance and the effect of light output from the resonant loop.

[0041] The preparation process in this embodiment is as follows: A microwave antenna 23 is etched on the first wafer 21, a heat sink window is fabricated and two heat sinks 26 are mounted, a first light source 24 and a second light source 25 are mounted on the two heat sinks 26 respectively, a diamond NV color center 22 is mounted on the microwave antenna 23, and two guide mirrors 27 are mounted, thereby obtaining the sensing element substrate 2.

[0042] Two light source windows 33, a color center window 32, a reflector window 34, and a guide mirror window 35 are formed on the second wafer 31, and a first reflector 36 is mounted in the reflector window 34, thereby obtaining the light channel substrate 3.

[0043] Three sensor windows 45 are formed on the third wafer 41, and the filter, first photodetector 42, second photodetector 43 and third photodetector 44 are installed to obtain the cover plate 4.

[0044] The carrier PCB1, sensing element substrate 2, optical channel substrate 3, and cover plate 4 are bonded together by eutectic bonding process.

[0045] This embodiment can realize three magnetic measurement modes. During use, some or all of the light sources can be activated for detection as needed, making it very suitable for power grid current measurement. This embodiment can be used as a sensing element in existing quantum current transformers.

[0046] In this embodiment, when used as a sensing element in a quantum current transformer for measuring the current of a power grid bus, the current of the power grid bus generates a ring magnetic field in the surrounding space. This embodiment can accurately measure the magnetic field value and then calculate the corresponding current value of the power grid bus based on the magnetic field.

[0047] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. These embodiments are merely descriptions of preferred embodiments and are not intended to limit the scope or concept of the invention. The specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. Such combinations, as long as they do not violate the spirit of the present invention, should also be considered as part of this disclosure. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

[0048] This invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this invention and without departing from the design idea of ​​this invention, all modifications and improvements made by those skilled in the art to the technical solutions of this invention should fall within the protection scope of this invention. The technical content for which protection is sought in this invention has been fully described in the claims.

Claims

1. An opto-mechatronics integrated sensing chip, characterized in that, include: The sensing element substrate (2) integrates a microwave antenna (23), a first light source (24), a second light source (25), and a diamond NV color center (22). The diamond NV color center (22) has a trapezoidal structure and is attached to the microwave antenna (23). The two sides of the diamond NV color center (22) are respectively set as mirrored surfaces. The first light source (24) is used to output excitation light, and the second light source (25) is used to output absorption light. The output light of the first light source (24) and the second light source (25) is respectively incident on the mirrored surfaces on both sides of the diamond NV color center (22). The optical channel substrate (3) integrates a first reflector (36); one side of the sensing element substrate (2) is connected to one side of the optical channel substrate (3), so that the first reflector (36) faces the trapezoidal bottom surface of the diamond NV color center (22); the first reflector (36) and the mirrored surfaces on both sides of the diamond NV color center (22) form an optical resonant loop, and the excitation light and absorption light can be trapped and cycled multiple times in the optical resonant loop and output through the first reflector (36). During the cycle, the excitation light and absorption light pass through the diamond NV color center (22). The sealing plate (4) integrates a first photodetector (42), a second photodetector (43), and a third photodetector (44). One side of the sealing plate (4) is connected to the other side of the light channel substrate (3). The first photodetector (42) is used to detect the fluorescence generated by the diamond NV color center (22) when it is excited. The second photodetector (43) is used to detect the absorbed light output through the first reflector (36). The third photodetector (44) is used to detect the excitation light output through the first reflector (36).

2. The opto-mechatronics integrated sensing chip according to claim 1, characterized in that, The excitation light output by the first light source (24) is green light.

3. The opto-mechatronics integrated sensing chip according to claim 1, characterized in that, The absorbed light output by the second light source (25) is infrared light.

4. The opto-mechatronics integrated sensing chip according to claim 1, characterized in that, The sensing element substrate (2) also integrates two heat sinks, with the first light source (24) and the second light source (25) respectively disposed on the two heat sinks.

5. The opto-mechatronics integrated sensing chip according to claim 1, characterized in that, The optical channel substrate (3) also integrates an actuator (361) to adjust the position of the first reflector (36).

6. The opto-mechatronics integrated sensing chip according to claim 1, characterized in that, In the sealing plate (4), a filter is provided at the position corresponding to the detection surface of at least one photodetector.

7. The opto-mechatronics integrated sensing chip according to claim 1, characterized in that, The sensing element substrate (2) is bonded to the optical channel substrate (3), and the optical channel substrate (3) is bonded to the cover plate (4).

8. A mechatronics sensor chip according to any one of claims 1-7, characterized in that, The sensing element substrate (2) also integrates two guide mirrors (27). When one side of the sensing element substrate (2) is connected to one side of the optical channel substrate (3), one side of the first reflector (36) faces the trapezoidal bottom surface facing the diamond NV color center (22), and the other side of the first reflector (36) faces the two guide mirrors (27). One guide mirror (27) is used to reflect the excitation light output by the first reflector (36), and the other guide mirror is used to reflect the absorption light output by the first reflector (36). The second photodetector (43) detects the absorbed light reflected by one of the guide mirrors, and the third photodetector (44) detects the excitation light reflected by the other guide mirror.

9. The opto-mechatronics integrated sensing chip according to claim 8, characterized in that, The guide mirror (27) is a prism, and a reflective film is coated on the reflective surface of the guide mirror (27).

10. The application of an opto-mechatronics sensing chip as described in any one of claims 1-9 as a sensing element in a quantum current transformer.

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