Magnetometer probe and diamond sample

Abstract

The invention discloses a magnetometer probe and a diamond sample, and relates to the technical field of measurement, and the magnetometer probe is characterized in that in an integrated optical path module, a laser irradiates the diamond sample to enable the diamond sample to emit fluorescence, and the fluorescence passes through a first optical filter and is collected by a first photodiode; in the magnetic field module, a magnetic flux collector is composed of two symmetrically-arranged magnetic flux plates, the two opposite ends of the two magnetic flux plates are arranged in a spaced mode to form a clamping channel used for clamping a diamond sample, the number of magnets is two, and the two opposite faces of the two magnets are opposite in magnetism; in the microwave antenna module, a microwave antenna piece is provided with a microwave transmission line of which the head and the tail are respectively connected with corresponding radio frequency connectors, the middle part of the microwave transmission line is n-shaped, and the n-shaped microwave transmission line is positioned under the diamond sample; and a heat dissipation module. According to the technical scheme, the magnetic flux collector is arranged to improve the magnetic measurement sensitivity of the magnetometer probe, and the middle part of the microwave transmission line is arranged to be n-shaped to realize the uniformity of microwave distribution.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of measurement technology, in particular to a magnetometer probe and a diamond sample. BACKGROUND

[0002] Among many magnetic sensitive systems, solid-state spins are widely studied and applied in the field of magnetic measurement due to their high sensitivity and high stability. NV color center is a point defect in diamond and also a solid-state spin system most widely studied in recent years. However, the existing integrated magnetometer probe based on diamond NV color center has low magnetic measurement sensitivity.

[0003] Therefore, it is necessary to design a magnetometer probe to improve the magnetic measurement sensitivity. SUMMARY

[0004] Therefore, the present application provides a magnetometer probe, which can improve the magnetic measurement sensitivity and realize the uniformity of microwave distribution through the arrangement of the magnetic flux concentrator and the microwave transmission line in the shape of Chinese character '。

[0005] The present application also provides a diamond sample detected by the above-mentioned magnetometer probe.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0007] A magnetometer probe comprises:

[0008] An integrated optical path module, which comprises a laser, a first optical filter and a first photodiode; the laser irradiates a diamond sample to make it emit fluorescence, and the fluorescence passes through the first optical filter and is collected by the first photodiode;

[0009] A magnetic field module, which comprises a magnetic flux concentrator and a magnet; the magnetic flux concentrator is composed of two magnetic flux plates, the two magnetic flux plates are symmetrically arranged, and the opposite ends of the two magnetic flux plates are arranged at intervals to form a clamping channel for clamping the diamond sample; the number of the magnet is two, the opposite faces of the two magnets are magnetically opposite, and the two magnets are used to provide an amplified bias static magnetic field for the magnetic flux concentrator;

[0010] A microwave antenna module, which comprises a microwave antenna and a radio frequency connector; the number of the radio frequency connector is two, the microwave antenna is provided with a microwave transmission line, the microwave transmission line is connected to the corresponding radio frequency connector at the head and tail respectively, the middle part of the microwave transmission line is in the shape of Chinese character ', and the microwave transmission line in the shape of Chinese character'is located directly below the diamond sample; the magnetic flux concentrator is arranged above the microwave antenna;

[0011] A heat dissipation module; the heat dissipation module comprises a heat dissipation base, and the integrated optical path module, the magnetic field module and the microwave antenna module are all mounted on the heat dissipation base.

[0012] Preferably, the top surface of the first optical filter is bonded with the first photodiode, and the bottom surface of the first optical filter is located directly above the diamond sample.

[0013] Preferably, the integrated optical path module further comprises:

[0014] a second optical filter, a third optical filter and a second photodiode which are bonded in sequence;

[0015] a beam splitter cube, a half-wave plate and a plano-convex lens;

[0016] The beam splitter cube is located between the laser and the laser channel of the diamond sample, and at least divides the laser emitted by the laser into two paths; one of the lasers is collected by the second photodiode through the second optical filter and the third optical filter, and the other laser irradiates the diamond sample through the half-wave plate and the plano-convex lens to make it emit fluorescence.

[0017] Preferably, the integrated optical path module further comprises:

[0018] a second optical filter, a third optical filter and a second photodiode which are bonded in sequence;

[0019] a half-wave plate and a plano-convex lens;

[0020] The laser emitted by the laser passes through the half-wave plate, the plano-convex lens and the diamond sample in sequence, and then passes through the second optical filter and the third optical filter in sequence to be collected by the second photodiode.

[0021] Preferably, the magnets are symmetrically arranged with respect to the clamping channel, and the magnets are arranged at intervals with the side edges of the magnetic flux plate members on the same side.

[0022] Preferably, the microwave antenna member comprises a microwave antenna chip and a carrier circuit board;

[0023] The microwave transmission line is arranged on the top surface of the microwave antenna chip, the radio frequency connector and the bottom surface of the microwave antenna chip are arranged on the top surface of the carrier circuit board, and the bottom surface of the carrier circuit board is arranged on the heat dissipation base;

[0024] The carrier circuit board is provided with a circuit board transmission line, and the radio frequency connector is connected to the microwave transmission line through the circuit board transmission line.

[0025] Preferably, the bottom surface of the magnetic flux concentrator is closely attached to and fixed on the microwave antenna chip, and an insulating layer is arranged therebetween.

[0026] Preferably, the integrated optical path module, the magnetic field module, and the microwave antenna module are all mounted on the top surface of the heat dissipation base, and the bottom surface of the heat dissipation base is provided with heat dissipation fins.

[0027] A diamond sample, detected using the aforementioned magnetometer probe, wherein the diamond sample is a strip-shaped thin sheet, and the diamond sample is coated with a reflective film except for the side facing away from the first photodiode.

[0028] Preferably, the side of the diamond sample facing away from the first photodiode is a pointed tip; wherein the pointed tip is a right-angled triangular tip or an isosceles triangular tip.

[0029] As can be seen from the above technical solution, the magnetometer probe provided by the present invention integrates the optical path module, magnetic field module, microwave antenna module and heat dissipation module, making the structure of each component compact; in order to ensure the magnetic measurement sensitivity of the magnetometer probe, a magnetic flux concentrator composed of two magnetic flux plates is set; in order to achieve the uniformity of microwave distribution, the middle part of the microwave transmission line is set in a Z-shape.

[0030] The present invention also provides a diamond sample, wherein the side of the diamond sample facing away from the first photodiode is set as a tip, thereby improving the efficiency of the first photodiode in collecting fluorescence. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a three-dimensional schematic diagram of an embodiment of the overall structure of the magnetometer probe provided in this invention.

[0033] Figure 2 This is a three-dimensional schematic diagram of another embodiment of the overall structure of the magnetometer probe provided in this invention.

[0034] Figure 3 A perspective view of an embodiment of the integrated optical path module provided in this invention;

[0035] Figure 4 A perspective view of another embodiment of the integrated optical path module provided in this invention;

[0036] Figure 5 for Figure 3 The front view;

[0037] Figure 6 for Figure 4 The front view;

[0038] Figure 7 A schematic diagram illustrating the combination of a magnetic field module and a diamond sample according to an embodiment of the present invention;

[0039] Figure 8 for Figure 7 A magnified view of a portion of the image;

[0040] Figure 9 A three-dimensional structural diagram of a microwave antenna module provided in an embodiment of the present invention;

[0041] Figure 10 A top view of a microwave antenna chip provided in an embodiment of the present invention;

[0042] Figure 11 for Figure 10 A magnified view of a portion of the image;

[0043] Figure 12 A three-dimensional structural diagram of the heat dissipation module provided in an embodiment of the present invention;

[0044] Figure 13 A side view of one embodiment of a diamond sample provided in this invention;

[0045] Figure 14 A side view of yet another embodiment of the diamond sample provided in this invention;

[0046] Figure 15 A side view of another embodiment of the diamond sample provided in this invention.

[0047] The meanings of the various reference numerals in the figure are as follows:

[0048] 10 is an integrated optical path module, 11 is a laser, 12 is a first filter, 13 is a first photodiode, 14 is a second filter, 15 is a third filter, 16 is a second photodiode, 17 is a beam splitter cube, 18 is a half-wave plate, and 19 is a plano-convex lens.

[0049] 20 is the magnetic field module, 21 is the magnetic flux concentrator, 211 is the magnetic flux plate, and 22 is the magnet;

[0050] 30 is the microwave antenna module, 31 is the microwave antenna chip, 32 is the RF connector, and 33 is the carrier circuit board;

[0051] 40 is the heat dissipation module, 41 is the heat dissipation base, 42 is the heat dissipation fins, and 43 is the laser mounting bracket;

[0052] 50 is a diamond sample, 51 is a right-angled triangle tip, and 52 is an isosceles triangle tip. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] The magnetometer probe provided in this embodiment of the invention includes:

[0055] Integrated optical path module 10, such as Figure 1 , Figure 2 and Figure 3 As shown, the integrated optical path module includes a laser 11, a first filter 12, and a first photodiode 13. The laser 11 irradiates the diamond sample 50 to make it emit fluorescence. The fluorescence passes through the first filter 12 and is collected by the first photodiode 13. It should be noted that the fluorescence irradiates the first photodiode 13 and is converted into an electrical signal output. The bottom surface of the first photodiode 13 collects the solid-state spin (i.e., NV color center) of the diamond sample 50, which is excited and emits fluorescence. The top surface of the first photodiode 13 is biased by an RF connector and outputs an electrical signal.

[0056] Magnetic field module 20; such as Figure 7 As shown, the magnetic field module 20 includes a flux concentrator 21 and magnets 22. The flux concentrator 21 is composed of two flux plates 211, which are symmetrically arranged and spaced apart at their opposite ends to form a clamping channel for clamping the diamond sample 50. There are two magnets 22, with opposite magnetic surfaces (i.e., the first surface of one magnet 22 faces the second surface of the other magnet 22, and the first and second surfaces have opposite magnetic properties). The two magnets 22 provide an amplified bias static magnetic field for the flux concentrator 21. It should be noted that the clamping channel is located on the laser path emitted by the laser 11.

[0057] Microwave antenna module 30, such as Figures 9-11As shown; microwave antenna module 30; the microwave antenna module 30 includes a microwave antenna element and an RF connector 32; there are two RF connectors 32, the microwave antenna element is provided with a microwave transmission line, the beginning and end of the microwave transmission line are respectively connected to the corresponding RF connector 32, the middle part of the microwave transmission line is in the shape of a "U", and the "U" shaped microwave transmission line is located directly below the diamond sample 50; the magnetic flux concentrator 21 is disposed on the microwave antenna element;

[0058] Heat dissipation module 40; The heat dissipation module includes a heat dissipation base 41, and the integrated optical path module 10, magnetic field module 20 and microwave antenna module 30 are all mounted on the heat dissipation base 41.

[0059] In the above technical solution, the integrated optical path module 10, magnetic field module 20, microwave antenna module 30 and heat dissipation module 40 are integrated to make the structure of each component compact; in order to ensure the magnetic sensitivity of the magnetometer probe, a magnetic flux concentrator 21 composed of two magnetic flux plates 211 is set; in order to achieve the uniformity of microwave distribution, the middle part of the microwave transmission line is set in a Z-shape.

[0060] In an alternative embodiment, such as Figure 3 As shown, the top surface of the first filter 12 is bonded to the first photodiode 13, and the bottom surface of the first filter 12 is located directly above the diamond sample 50. Preferably, to allow the first photodiode 13 to better collect the emitted fluorescence from the diamond sample 50, the first filter 12 and the first photodiode 13 are bonded with optical adhesive, and the bottom surface of the first filter 12 is bonded to the diamond sample 50. Specifically, the photosensitive area on the bottom surface of the first photodiode 13 is used to receive the fluorescence signal transmitted through the first filter 12 and convert it into an electrical signal, while the top surface is biased and outputs an electrical signal via an RF connector. To obtain higher fluorescence collection efficiency, the size of the photosensitive area of ​​the first photodiode 13 should at least completely cover the upper surface of the diamond sample 50.

[0061] In an alternative embodiment, such as Figure 3 As shown, the integrated optical path module 10 also includes:

[0062] The second filter 14, the third filter 15, and the second photodiode 16 are sequentially bonded together;

[0063] 17. Beam splitter cube; 18. Half-wave plate; 19. Plano-convex lens;

[0064] Among them, the beam splitter 17 is located on the laser channel between the laser 11 and the diamond sample 50, and splits the laser emitted by the laser 11 into at least two lasers; one laser is collected by the second photodiode 16 through the second filter 14 and the third filter 15, and the other laser is irradiated by the diamond sample 50 through the half-wave plate 18 and the plano-convex lens 19 to make it emit fluorescence.

[0065] In the above technical solution, after the laser emitted by the laser 11 enters the beam splitter cube 17, it is divided into two paths according to a certain beam splitting ratio. One path exits vertically upward (i.e., the vertically upward laser is collected by the second photodiode 16 after passing through the second filter 14 and the third filter 15), while the other path proceeds along the original beam direction. In the vertically upward exiting optical path, the second photodiode 16 and the third filter 15, as well as the second filter 14 and the third filter 15, are bonded together with optical adhesive. The surface of the second filter 14 is adhered to the surface of the beam splitter cube using optical adhesive. Furthermore, the vertically upward exiting optical path serves as the optical path for detecting the laser power after beam splitting, used to convert the split laser into an electrical signal to differentially eliminate noise caused by laser fluctuations in the fluorescence signal. In the optical path advancing along the original beam direction, to avoid the problems of existing technology (laser-emitted light typically has a certain divergence angle; after propagating a certain distance, the spot size increases significantly, leading to a decrease in optical power density, which in turn reduces the efficiency of solid-state spin excitation, resulting in a decrease in the overall resonant signal intensity of the magnetometer probe and a decrease in magnetic sensitivity), a plano-convex lens 19 (which can be of a relatively short focal length) is placed between the beam-splitting cubic 17 and the diamond sample 50. The focused laser beam enters the diamond sample 50, causing the diamond sample 50 to emit fluorescence. The first photodiode 13 receives the fluorescence containing magnetic field information and converts it into an electrical signal for subsequent processing. It should be noted that the second photodiode 16 can detect laser power and eliminate noise caused by laser fluctuations in the fluorescence signal.

[0066] In an alternative embodiment, such as Figure 4 and Figure 6 As shown, the integrated optical path module 10 also includes:

[0067] The second filter 14, the third filter 15, and the second photodiode 16 are sequentially bonded together;

[0068] Half-wave plate 18; plano lens 19;

[0069] The laser emitted by the laser 11 passes sequentially through the half-wave plate 18, the plano-convex lens 19, and the diamond sample 50, and then sequentially through the second filter 14 and the third filter 15 before being collected by the second photodiode 16.

[0070] In the above technical solution, the laser beam does not pass through the beam-splitting cube 17. Instead, it passes through the diamond sample 50, then through the second filter 14 and the third filter 15, and finally illuminates the second photodiode 16, where it is converted into an electrical signal output. The second photodiode 16 and the third filter 15, as well as the second filter 14 and the third filter 15, are bonded together with optical adhesive, forming a single unit. This unit is then fixed to a groove on the heat sink 41 near the diamond sample 50, ensuring that the surface of the second filter 14 faces the direction of the laser beam. Specifically, after the laser beam passes sequentially through the diamond sample 50, the second filter 14, and the third filter 15, it illuminates the second photodiode 16, forming the optical path for laser power detection. It should be noted that this portion of the optical path, after the laser beam passes sequentially through the diamond sample 50, is used to convert the laser beam passing through the diamond sample 50 into an electrical signal, differentially eliminating noise caused by laser fluctuations in the fluorescence signal. It should be noted that the second photodiode 16 can detect laser power and eliminate noise caused by laser fluctuations in the fluorescence signal.

[0071] In an alternative embodiment, such as Figure 7 As shown, in order to enable the magnet 22 to better focus and amplify the magnetic field sensed by the diamond sample 50, the magnet 22 is arranged symmetrically about the clamping channel, and the magnet 22 and the magnetic flux plate 21 on the same side are spaced apart. Preferably, the side of the magnetic flux plate 21 and the clamping channel are arranged parallel to each other.

[0072] In the above technical solution, it should be noted that the diamond sample 50 is clamped between the gaps of a pair of magnetic flux concentrators 21 (i.e., the clamping channel). Magnets 22 are located on both sides of the magnetic flux concentrators 21 and maintain a certain distance from them. The laser beam passes through the diamond sample 50 along the direction of the arrow, as shown... Figure 7As indicated by the arrow, the centers of the diamond sample 50, the flux concentrator 21, and the magnet 22 are all located in the same plane. The diamond sample 50 senses the external magnetic field and emits fluorescence after being excited by a laser (when the diamond sample 50 is excited by a laser within a certain wavelength range, transitions occur between the electron spin states of its internal NV color centers, emitting fluorescence carrying information about the external magnetic field). It should also be noted that the flux concentrator 21, composed of a pair of flux plates 211, is used to concentrate the magnetic flux in the nearby space, thereby amplifying the magnetic field sensed by the diamond sample 50 between the flux concentrators 21. The flux concentrator 21 is made of a high-permeability material, such as permalloy or Invar alloy. The bottom surface of the flux plate 211 is flat to ensure close contact with the microwave antenna components, thus achieving a compact structural design. Preferably, the flux plate 211 can be rod-shaped, trapezoidal, fan-shaped, etc., and can be manufactured using metal processing techniques (e.g., CNC machining).

[0073] In one of the alternative technical solutions, such as Figure 7 As shown, the flux plate 211 can be a combination of a trapezoid and a rectangle, and its thickness can be equal to the height of the diamond sample 50. Typically, the smaller end face of the flux plate 211 is closer to the diamond sample 50, and the larger end face is farther away. This makes the focusing effect of the flux concentrator 21 more significant. It should be noted that the focusing effect of the flux concentrator 21 is more significant when the magnetic flux is concentrated from the larger end face to the smaller end face along the length of the flux concentrator 21.

[0074] In one of the alternative technical solutions, such as Figure 7 As shown, the clamping channel between the two flux plates 211 precisely embeds or clamps the diamond sample 50. This clamping channel is small enough to allow for a higher gain factor of the flux concentrator on the internal magnetic field of the diamond sample 50, and to ensure that the diamond sample 50 does not tilt during assembly and remains stable, preventing loosening and ensuring that the principal axis direction of the NV color center of the diamond sample 50 remains consistent with the design. It should also be noted that, in order to obtain a more uniform magnetic field distribution inside the diamond sample 50, the two clamping surfaces of the flux plates 211 in contact with the diamond sample 50 need to be smooth and flat.

[0075] In one of the alternative technical solutions, such as Figure 7As shown, the clamping surfaces of the magnetic flux plate 211 are flat, which significantly increases the uniformity of the magnetic field felt by the diamond sample 50. This, in turn, increases the consistency of the magnetic field strength felt by each NV color center within the diamond sample 50 (avoiding a rough clamping surface, which would lead to a decrease in the consistency of the magnetic field strength felt by each NV color center within the diamond sample 50, a larger difference in resonant frequency, and ultimately a decrease in the resonance intensity at the overall resonance point of the diamond sample 50). It should be noted that the magnetic flux concentrator 21 amplifies the magnetic field to be measured, and the magnetic sensitivity of the magnetometer probe is increased by a corresponding factor compared to when there is no magnetic flux concentrator 21.

[0076] In one of the alternative technical solutions, such as Figure 7 As shown, magnet 22 provides a strong and uniform bias static magnetic field, which is amplified by flux concentrator 21 and applied to diamond sample 50. When using the NV color centers in diamond sample 50 for weak magnetic field measurements, a bias static magnetic field of a certain strength needs to be applied to eliminate the degeneracy of the electron spin ms=±1 energy levels of the NV color centers. The required bias static magnetic field can be provided by magnet 22. It should be noted that flux concentrator 21 is suitable for low-frequency magnetic fields; it can amplify not only the low-frequency magnetic field to be measured but also the bias static magnetic field.

[0077] In one of the alternative technical solutions, such as Figure 7 As shown, when the gap between the magnetic flux plates 211 is sufficiently small and a static magnetic field is applied using magnets 22, the uniformity of the magnetic field experienced by the diamond sample 50 is higher than that without a concentrator. A pair of magnets 22 are symmetrically positioned on both sides of the magnetic flux concentrator 21, with the magnets 22 maintaining a certain distance from the end faces of the magnetic flux plates 211, and the magnetization directions of the magnets being in the same direction and along the length of the magnetic flux plates 211. Preferably, a single magnet 22 can be used. It should be noted that the gap between the magnetic flux plates 211 can be between 0.1 mm and 0.9 mm.

[0078] In one of the alternative technical solutions, such as Figure 9 As shown, the microwave antenna device includes: a microwave antenna chip 31 and a carrier circuit board 33;

[0079] The microwave transmission line is disposed on the top surface of the microwave antenna chip 31, the radio frequency connector 32 and the bottom surface of the microwave antenna chip 31 are disposed on the top surface of the carrier circuit board 33, and the bottom surface of the carrier circuit board 33 is disposed on the heat sink 41.

[0080] The carrier circuit board 33 is provided with a circuit board transmission line, and the radio frequency connector 32 is connected to the microwave transmission line through the circuit board transmission.

[0081] In this technical solution, the carrier circuit board 33 is used to carry the microwave antenna chip 31 and transfer the microwave source to the microwave antenna chip 31. The carrier circuit board 33 can be fabricated using circuit board manufacturing processes; specifically, such as... Figures 9-11 As shown, the microwave transmission line on the microwave antenna chip 31 is used to provide a high-intensity and relatively uniformly distributed microwave field inside the diamond sample 50. The microwave antenna chip 31 adopts the form of a grounded coplanar waveguide, and the U-shaped microwave transmission line of the microwave antenna chip 31 avoids passing under the area covered by the magnetic flux concentrator 21, so as to reduce the impact of the magnetic flux concentrator 21 on the microwave conversion efficiency of the microwave antenna chip 31. To further explain, this avoids the problem of traditional "Ω" loop antennas (where most of the microwave transmission line of the "Ω" loop antenna is located directly below the magnetic flux concentrator 21, causing the microwave field to be shielded or absorbed by the material of the magnetic flux concentrator 21, thus significantly reducing the intensity of the microwave field reaching the interior of the diamond sample 50).

[0082] In one alternative embodiment, the microwave antenna chip 31 is attached to the carrier circuit board 33 for easy manufacturing; in another embodiment, to save materials, the microwave transmission line is directly disposed on the carrier circuit board 33.

[0083] In an optional embodiment, the bottom surface of the flux concentrator 21 is tightly attached to the microwave antenna chip 31, thereby bringing the diamond sample 50 in the gap of the flux concentrator 22 closer to the microwave transmission line, and an insulating layer is provided between them. This arrangement in this technical solution reduces the required microwave source input power when the diamond sample 50 experiences the same intensity of microwave field, thus facilitating the integration of this magnetometer probe. Furthermore, fixing the flux concentrator 22 to the carrier circuit board 33 makes the magnetometer probe structure more compact and more stable. The thin insulating layer between the flux concentrator 22 and the microwave antenna chip 31 prevents direct contact between the flux concentrator 22 and the metal layer of the microwave antenna chip 31, thereby avoiding any impact on antenna performance. Preferably, the microwave antenna chip 31 is cut into an I-shape and has two through holes for fixing. The microwave antenna chip 31 can be fabricated using microfabrication processes.

[0084] In an optional embodiment, the carrier circuit board 33 is used to carry the microwave antenna chip 31 and transfer the microwave source to the microwave antenna chip 31. The carrier circuit board 33 can be fabricated using circuit board manufacturing processes. Figure 2 and Figure 9As shown, the carrier circuit board 33 has four through holes. Fasteners can be used to fix the carrier circuit board 33 to the heat sink base 41. Two of the four through holes are concentric with two through holes on the microwave antenna chip 31, thus securing the microwave antenna chip 31. The microwave antenna chip 31 and the carrier circuit board 33 can be fixed together by adhesive or soldering. It should be noted that the carrier circuit board 33 has an area for placing the magnet 22. After adjusting the magnet 22 to a suitable position, it is fixed to the carrier circuit board 33.

[0085] In an alternative technical solution, the RF connector 32 is used to connect the carrier circuit board 33 to a microwave source or a 50Ω load. The connector 32 is soldered onto the carrier circuit board 33, and its signal lines are connected through the carrier circuit board 33 and the microwave antenna chip 31. In addition, one of the RF connectors 32 is connected to an external microwave source to provide microwave input; the other RF connector 32 is connected to a 50Ω load to complete impedance matching.

[0086] In an optional technical solution, the integrated optical path module 10, the magnetic field module 20, and the microwave antenna module 30 are all mounted on the top surface of the heat dissipation base 41. The bottom surface of the heat dissipation base 41 is provided with heat dissipation fins 42, a series of which are used to improve heat dissipation efficiency. Specifically, as shown... Figure 1 , Figure 2 and Figure 12 As shown, the heat dissipation base 41 is equipped with a laser mounting bracket 43 for fixing the laser, and it makes thermal contact with the laser 11 to dissipate the heat generated by the laser 11 during operation and provide a larger heat dissipation area. The laser mounting bracket 43 should be made of a metal material with good thermal conductivity and heat dissipation properties, such as copper or aluminum. The laser mounting bracket 43 can be manufactured using metal processing techniques (such as CNC machining). Filling the contact surface between the laser 11 and the laser mounting bracket 43 with thermally conductive silicone or similar materials helps to further improve heat dissipation efficiency. Threaded holes can be provided on the top and sides of the laser mounting bracket 43 to allow for fixing with screws when installing the laser 11. The laser mounting base 43 has a pair of slots at its bottom, which mate with the corresponding vertical slots on the heat sink base 41, so that the laser mounting base 43 can be installed on the heat sink base 41 using fasteners (screws or bolts). The fixed fit between the laser mounting base 43 and the heat sink base 41 allows the angle and direction of the laser emitted by the laser 11 to be adjusted within a certain range, making it easy to adjust the laser beam emitted by the laser 11 to a predetermined angle and direction during installation, thereby facilitating the adjustment and fixing of other components in the integrated optical path module 10.

[0087] In an alternative technical solution, the heat sink 41 can be made of a metal material with good thermal conductivity and heat dissipation, such as copper or aluminum. The heat sink 41 can be manufactured using metal processing techniques (such as CNC machining). If necessary, a fan can be used along the heat dissipation fins 42 of the heat sink 41 to further improve heat dissipation efficiency. The heat sink 41 also has multiple threaded holes, slots, and recesses for fixing the laser mounting base 43 and other components of the probe. The threaded holes, slots, and recesses allow the various components to be directly or indirectly fixed to the heat sink 41, making the magnetometer probe a single unit with stability and portability.

[0088] In an optional technical solution, the heat sink 41 is also used to fix the half-wave plate 18, the beam splitter cube 17, and the photodiode. In addition, an adjustment shim is provided between the heat sink 41 and the carrier circuit board 33 to adjust the height of the diamond sample 50 and the angle at which the laser beam enters the diamond sample 50. Specifically, the carrier circuit board 33 has four through holes, and the heat sink 41 has four threaded holes at corresponding positions. The carrier circuit board 33 and the heat sink 41 are connected by fasteners (screws or bolts). By adding or removing shims or rotating nuts, the height and pitch angle of the carrier circuit board 33 can be adjusted within a certain range, thereby adjusting the height and angle of the diamond sample 50 located on the carrier circuit board 33. The shims can be fixed by glue and contact parts, and the contact parts can be the bottom surface of the heat sink 41 or the carrier circuit board 33.

[0089] A diamond sample, tested using the aforementioned magnetometer probe, wherein the diamond sample 50 is a strip-shaped thin sheet, such as... Figures 13-15 As shown, the diamond sample 50 is coated with a reflective film on all sides except the side facing away from the first photodiode 13. In this technical solution, the reflective film can reflect the fluorescence emitted through the other surfaces of the diamond sample 50 back into the diamond sample 50, thereby improving the fluorescence collection efficiency.

[0090] To optimize the above technical solution and further improve the fluorescence collection efficiency, the side of the diamond sample 50 facing away from the first photodiode 13 is a pointed tip; wherein, the tip is a right-angled triangular tip 51 or an isosceles triangular tip 52, such as... Figure 14 and Figure 15 As shown.

[0091] It should be noted that, as Figure 14 As shown, a bevel is cut at a certain angle along one edge of the diamond sample 50, resulting in significantly higher fluorescence collection efficiency compared to the original cuboid shape. In this technical solution, the tip is a right-angled triangular tip 51. In another optional technical solution, as... Figure 15As shown, two beveled surfaces are cut at a certain angle along the two edges of the diamond sample 50, resulting in a significantly higher fluorescence collection efficiency than the original cuboid shape. In this technical solution, the tip is an isosceles triangular tip 52. It should also be noted that the fluorescence collection efficiency of the double-beveled cutting scheme (i.e., the isosceles triangular tip 52) is slightly higher than that of the single-beveled cutting scheme (i.e., the tip is a right-angled triangular tip 51).

[0092] In one of the alternative technical solutions, such as Figures 13-15 As shown, firstly, optical adhesive can be used to connect and fill the area between the diamond sample 50 and the surface of the first filter 12. Filling with optical adhesive can reduce the total internal reflection angle at the interface of the diamond sample 50, thus making it easier for fluorescence to be emitted from the upper surface of the diamond sample 50. The fluorescence collection efficiency of this design is significantly higher than that when there is an air gap between the diamond sample 50 and the first filter 12. A further optimization involves making the strip into a cuboid shape and polishing the tip of the cuboid-shaped diamond sample 50 to a cutting surface, which can significantly improve the fluorescence collection efficiency.

[0093] The technical features mentioned above, those to be mentioned below, and those shown individually in the accompanying drawings can be combined arbitrarily, provided that the combined technical features are not contradictory. All feasible combinations of features are the technical content explicitly described herein. Any one of the multiple sub-features contained in the same statement can be applied independently, without necessarily being applied together with other sub-features.

[0094] The following is a further description of this solution with reference to specific embodiments:

[0095] In a specific embodiment of the integrated optical path module 10, such as Figures 3-6 As shown, laser 11 is used to provide excitation light to excite solid-state spin and generate fluorescence. Taking the excitation of the NV color center in diamond sample 50 as an example, the wavelength of laser 11 is around 532 nm. The optical axis of the laser beam passes horizontally through the exact center of diamond sample 50.

[0096] like Figures 3-6 As shown, the half-wave plate 18 is rotatable and used to change the polarization direction of the laser to enhance the resonance signal intensity at the selected resonance point. The position of the half-wave plate 18 on the optical axis is not strictly required; it can be directly clipped into the pre-grooved position on the heat sink base 41 and rotated to the optimal angle before being fixed.

[0097] like Figures 3-6As shown, the plano-convex lens 19 is used to focus the diverging beam emitted from the laser 11 onto the exact center of the diamond sample 50. The beam waist diameter of the focused beam is smaller than the beam diameter without the plano-convex lens 19, thereby increasing the optical power density of the laser inside the diamond sample 50. The plano-convex lens 19 can be fixed on the carrier circuit board 33.

[0098] like Figures 3-6 As shown, the first filter 12 is used to filter out the laser light scattered after entering the diamond sample 50 and allow the fluorescence emitted by the diamond sample 50 to pass through, thereby reducing the interference of the laser light on the fluorescence signal. A long-pass red glass filter is selected here. To ensure the filtering effect, the size of the first filter 12 should be equivalent to or slightly larger than the size of the first photodiode 13. It should be noted that the long-pass red glass filter is a type of filter that allows light with wavelengths greater than a certain cutoff wavelength to pass through while blocking (absorbing or reflecting) light with shorter wavelengths.

[0099] like Figures 3-6 As shown, the third filter 15 is used to filter out light outside the laser band, reducing interference from other ambient light and fluorescence on the laser signal. It should be noted that the laser light from the upward-splitting laser beam in the beam-splitting cube 17 (the second filter 14 filters out the non-laser bands of this laser), as... Figure 3 As shown; or the laser emitted after passing through the diamond sample 50 (the second filter 14 filters out the non-laser bands of this laser), such as Figure 4 As shown. A bandpass green glass filter was selected here. To ensure the filtering effect, the size of the third filter 15 should be similar to or slightly larger than the size of the second photodiode 16. A bandpass green glass filter is a type of filter that allows light within a specific wavelength range to pass through while blocking (absorbing or reflecting) light of other wavelengths.

[0100] like Figures 3-6 As shown, the second filter 14 attenuates excessively strong laser signals to prevent photodiode 2 from saturating. It can also be used to attenuate the laser signal to an intensity similar to the fluorescence signal, avoiding nonlinear effects caused by a large difference in the intensity of the two signals. Specifically, the laser signal from the upward-splitting laser beam in the beam-splitting cube 17 is attenuated by the third filter 15. Figure 3 As shown; or the laser emitted after passing through the diamond sample (the third filter 15 attenuates the laser signal), such as Figure 4 As shown; a gray glass neutral density filter was selected here. If the intensities of the two signals are similar, this optical component can be omitted.

[0101] like Figure 4 and Figure 6As shown, the components of the integrated optical path module 10 are mostly connected and fixed using optical adhesive, which makes the structure of this magnetometer probe compact and stable.

[0102] In an optional embodiment, while maintaining the basic spatial relationship between the various parts, the assembly and connection methods can be replaced with other mechanical assembly, adhesive bonding, micro-assembly, bonding processes, etc. Mechanical holes, positioning patterns, fixing grooves, etc., on the parts can be adjusted accordingly based on changes in the assembly and connection methods. In the integrated optical path module 10, depending on the beam characteristics (such as wavelength, divergence angle, and beam quality) of different excitation light sources, the beam can be focused inside the diamond sample 50 by increasing or decreasing the number of plano-convex lenses 19, while keeping the overall size relatively unchanged. Furthermore, the order of the beam-splitting cube 17, plano-convex lens 19, and half-wave plate 18 in the optical path can also be adjusted according to the optical path design.

[0103] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0104] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A magnetometer probe, characterized by, It comprises: An integrated optical path module (10); the integrated optical path module comprises a laser (11), a first optical filter (12) and a first photodiode (13); the laser (11) irradiates a diamond sample (50) to make it emit fluorescence, and the fluorescence passes through the first optical filter (12) and is collected by the first photodiode (13); A magnetic field module (20); the magnetic field module (20) comprises a magnetic flux concentrator (21) and a magnet (22), the magnetic flux concentrator (21) is composed of two magnetic flux plates (211), the two magnetic flux plates (211) are symmetrically arranged, and the opposite ends of the two magnetic flux plates (211) are arranged at intervals to form a clamping channel for clamping the diamond sample (50); the number of the magnet (22) is two, the opposite two faces of the two magnets (22) are magnetically opposite, and the two magnets (22) are used to provide an amplified bias static magnetic field for the magnetic flux concentrator (21); A microwave antenna module (30); the microwave antenna module (30) comprises a microwave antenna and a radio frequency connector (32); the number of the radio frequency connector (32) is two, the microwave antenna is provided with a microwave transmission line, the microwave transmission line is connected to the corresponding radio frequency connector (32) at the head and tail respectively, the middle part of the microwave transmission line is a few characters, and the microwave transmission line of the few characters is located directly below the diamond sample (50); the magnetic flux concentrator (21) is arranged above the microwave antenna; a heat dissipation module (40); the heat dissipation module comprises a heat dissipation base (41), and the integrated optical path module (10), the magnetic field module (20) and the microwave antenna module (30) are all installed on the heat dissipation base (41).

2. The magnetometer probe of claim 1, wherein, The top surface of the first optical filter (12) is bonded with the first photodiode (13), and the bottom surface of the first optical filter (12) is located directly above the diamond sample (50).

3. The magnetometer probe of claim 2, wherein, The integrated optical path module (10) further comprises: a second optical filter (14), a third optical filter (15) and a second photodiode (16) bonded in sequence; a beam splitting cube (17), a half-wave plate (18) and a plano-convex lens (19); Among them, the beam splitting cube (17) is located between the laser channel between the laser (11) and the diamond sample (50), and at least two lasers are emitted by the laser (11); one of the lasers is collected by the second photodiode (16) through the second optical filter (14) and the third optical filter (15), and the other laser irradiates the diamond sample (50) through the half-wave plate (18) and the plano-convex lens (19) to make it emit fluorescence.

4. The magnetometer probe of claim 2, wherein, The integrated optical path module (10) further comprises: a second optical filter (14), a third optical filter (15) and a second photodiode (16) bonded in sequence; a half-wave plate (18) and a plano-convex lens (19); The laser emitted by the laser (11) passes through the half-wave plate (18), the plano-convex lens (19) and the diamond sample (50) in sequence, and then passes through the second filter (14) and the third filter (15) in sequence and is collected by the second photodiode (16).

5. The magnetometer probe of claim 2, wherein, The magnets (22) are symmetrically arranged with respect to the clamping channel, and the magnets (22) are arranged in a spaced manner with respect to the side edges of the magnetic flux plates (211) on the same side.

6. The magnetometer probe of claim 1, wherein, The microwave antenna member comprises a microwave antenna chip (31) and a bearing circuit board (33). The microwave transmission line is arranged on the top surface of the microwave antenna chip (31), the radio frequency connector (32) and the bottom surface of the microwave antenna chip (31) are arranged on the top surface of the bearing circuit board (33), and the bottom surface of the bearing circuit board (33) is arranged on the heat dissipation base (41). The bearing circuit board (33) is provided with a circuit board transmission line, and the radio frequency connector (32) is connected to the microwave transmission line through the circuit board transmission line.

7. The magnetometer probe of claim 6, wherein, The bottom surface of the magnetic flux concentrator (21) is tightly attached to and fixed on the microwave antenna chip (31), and an insulating layer is arranged therebetween.

8. The magnetometer probe of claim 1, wherein, The integrated optical path module (10), the magnetic field module (20) and the microwave antenna module (30) are all mounted on the top surface of the heat dissipation base (41), and the bottom surface of the heat dissipation base (41) is provided with heat dissipation fins (42).

9. A diamond sample, characterized in that, The diamond sample (50) is a strip-shaped sheet, and the diamond sample (50) is coated with a reflective film except for one side facing away from the first photodiode (13).

10. The diamond sample of claim 9, wherein, The side of the diamond sample (50) facing away from the first photodiode (13) is a pointed end; wherein the pointed end is a right-angled triangular pointed end (51) or an isosceles triangular pointed end (52).

Images