Sensor system for detecting a medium

Abstract

The invention relates to a magnetic field sensor (1) for detecting a magnetic field, comprising a magneto-optical material (2), an excitation light source (3), which is designed to emit excitation radiation for exciting an electronic state of the magneto-optical material (2), a microwave source (4), which is designed to generate an electromagnetic field, a detector (5), and a magnetic field generating device (6), the invention relates to a magneto-optical device (1) comprising a magneto-optical material (2) having an excitation radiation, a detector for feeding a resonator structure (8), which detector is designed to detect fluorescent radiation emitted by the magneto-optical material (2) after irradiation with the excitation radiation, and a magnetic field generating device arranged and designed to generate a permanent magnetic field in the region of the magneto-optical material (2). Furthermore, the magnetic field sensor (1) comprises a resonator structure (8) arranged on the dielectric (7), which resonator structure is designed to deform the electromagnetic field emitted by the microwave source (4) in such a way that a microwave field is generated, which microwave field is suitable for manipulating the spin state of the magneto-optical material (2). The magneto-optical material (2), the excitation light source (3), the detector (5) and the resonator structure (8) are arranged in a closed space (9).

Description

Technical Field

[0001] The present invention relates to a magnetic field sensor based on NV diamond. Background Art

[0002] Diamond crystals whose lattice has defects in the form of NV centers have been the subject of research for many years. In an NV center, a nitrogen atom occupies a lattice site of a carbon atom, wherein in the immediate vicinity of this nitrogen atom—in turn at the lattice site of a carbon atom—a defect is arranged. If such a lattice is irradiated with excitation radiation having a wavelength between 490 nm and 575 nm, a change from the ground state to the NV center is induced in the lattice. 3 A2 to excited state 3 Electronic transition of E. The NV center is excited from the excited state with emission of fluorescence radiation in the wavelength range between 600 nm and 850 nm. 3 E relaxes to the ground state again 3 In A2.

[0003] Ground State 3 A2 has three magnon states with m s =0, m s = ±1. With m s = 0 and m s = ±1 states have an energy difference of 2.87 GHz (Zero Field Splitting). 3 E also has three magnon states, which have m s =0, m s = ±1. Now, if in the ground state 3 The NV center in A2 is exposed to an alternating magnetic field with a frequency of 2.87 GHz (usually and hereinafter, an alternating magnetic field in the frequency range between 1 and 4 GHz is referred to as a “microwave field”), and the NV center is s =0, 3 A2 ground state and m s = ±1, 3 Now, upon irradiation with excitation radiation, the NV center partially oscillates from m s = ±1, 3 A2 is placed in the ground state to m s = ±1, 3E excited state. From there, the NV center relaxes back to the ground state, predominantly without radiation. If the intensity of the fluorescence radiation is measured as a function of the frequency of the microwave field, a sudden drop in the intensity of the fluorescence radiation (the so-called peak) occurs at a frequency of 2.87 GHz. The sudden drop in the intensity of the fluorescence radiation can be explained by the fact that when a microwave field is irradiated at a frequency of 2.87 GHz, the available s =0, 3 The A2 ground state contains relatively few NV centers that can be optically excited and relax to m with emission of fluorescent radiation. s = ±1, 3 A2 ground state.

[0004] In an external magnetic field, m s = ±1, 3 The A2 ground state splits into two states with spin quantum number m s =1 and m s = -1 (Zeemann effect). If the intensity of the fluorescence radiation is measured while changing the frequency of the microwave field, two peaks are obtained. The frequency at which these peaks appear is related to m s = ±1, 3 The magnitude of the splitting of the A2 ground state and therefore depends on the field strength of the external magnetic field.

[0005] Such a magnetic field sensor is known, for example, from DE 10 2020 204 732. Therein, excitation radiation is generated by means of a laser diode, which is arranged in a cavity. Here, the cavity is formed by a recess in a carrier wafer and a glass substrate that hermetically seals the cavity. The excitation radiation is conducted through the glass substrate to a plane located below it, in which the excitation radiation is focused on the NV diamond. The plane below has a substrate, on which the remaining system components, such as diamond, high-frequency device, photodetector and other optical components are arranged. The substrate is closed by means of a cap-shaped substrate, which contains an opening through which the excitation radiation can reach the diamond. Therefore, the laser diode is arranged in a closed space separately from the remaining components of the magnetic field sensor. Such a magnetic field sensor with two separate cavities requires space and cannot be further miniaturized. In addition, the alternating magnetic field generated by the high-frequency device can propagate freely, so that the characteristics of the high-frequency device are affected by the material in the environment of the magnetic field sensor. As a result, the specifications of the magnetic field sensor can be affected and the magnetic field sensor cannot be used universally. Furthermore, components arranged outside the magnetic field sensor may be disturbed by the alternating magnetic field and the electromagnetic compatibility of the magnetic field sensor may be limited. Summary of the invention

[0006] The object of the present invention is to provide a magnetic field sensor which does not have the disadvantages of the prior art.

[0007] The present invention relates to a magnetic field sensor for detecting a magnetic field. Advantageous embodiments of the present invention are shown below.

[0008] The present invention provides a magnetic field sensor for detecting a magnetic field, the magnetic field sensor having a magneto-optical material, an excitation light source, a microwave source and a detector. The magneto-optical material may be a diamond crystal, the lattice of which has defects in the form of NV centers. The excitation light source is configured to emit excitation radiation for exciting the electronic state of the magneto-optical material. The excitation light source may be a laser diode having a wavelength between 490 nm and 575 nm. The microwave source is configured to generate an electromagnetic field, which can feed a resonator structure, i.e., can supply power to the resonator structure. The detector is configured to detect fluorescence radiation emitted by the magneto-optical material after being irradiated with the excitation radiation. In addition, the magnetic field sensor has a magnetic field generating device, which is arranged and configured to generate a permanent magnetic field in the region of the magneto-optical material.

[0009] The resonator structure is arranged on the dielectric and is configured to amplify and deform the alternating electromagnetic field generated by the microwave source at least in a predefined frequency band so that a uniform microwave field can be formed in the region of the magneto-optical material. The microwave field generated in this way is suitable for manipulating the spin state of the magneto-optical material and has, for example, one or more frequencies in a frequency band between 2.5 GHz and 3 GHz.

[0010] The deposition of organic substances on optical components, especially on the excitation light source, is problematic. In order to protect the magneto-optical material, the excitation light source, the detector and the resonator structure from this influence and from other environmental influences, the magneto-optical material, the excitation light source, the detector and the resonator structure are arranged in a closed space. The magneto-optical material, the excitation light source and the detector can also be arranged on a dielectric. The magneto-optical material, the excitation light source, the detector and the resonator structure are arranged in a closed, especially airtightly closed space so that the magnetic field sensor can be compactly configured. In addition, the spatial proximity of the resonator structure to the magneto-optical material can be achieved so that the microwave field amplified and deformed by the resonator structure can be efficiently and largely losslessly coupled into the magneto-optical material.

[0011] Here, the first metal layer is arranged below the resonator structure, which is arranged on the dielectric, and the second metal layer is arranged above the resonator structure, which is arranged on the dielectric. The first and second metal layers are particularly designed to shield the microwave field amplified and deformed by the resonator structure from the upper side and the lower side of the closed space. In addition, the first and / or second metal layer is designed to deform the microwave field amplified by the resonator structure.

[0012] In this way, not only can the microwave fields be shielded from the environment of the enclosed space, but also the electronic and optical components of the magnetic field sensor can be protected from the ambient conditions.

[0013] The first and / or second metal layer is particularly configured as a ground plane, which is connected to the electrical ground of the microwave source. Here, the wave impedance, shape and propagation speed of the electromagnetic microwave field are mainly affected by the material of the dielectric and by the position of the first and / or second metal layer (connected to the ground).

[0014] The resonator structure may include a conductive structure, which is arranged on a dielectric and is implemented, for example, as an omega resonator, a planar slot waveguide structure or a loop gap resonator. The resonator structure forms a resonator together with a dielectric and a first and / or second metal layer configured as a ground plane, on which the resonator structure is arranged. The wave impedance, shape and propagation speed of the electromagnetic microwave field are mainly determined by the material of the dielectric and the position of the first and second metal layers connected to the ground. Here, the geometry of the resonator is selected so that the microwave field is generated so that it is uniform in the area where the magneto-optical material is arranged and locally confined to the area. Here, the resonator is particularly configured to amplify frequencies in one or more frequency bands in the range between 2.5 and 3.1 GHz. Outside these frequency bands, it is possible that the efficiency of field generation is greatly reduced, so that the power of the microwave source is no longer sufficient for the meaningful operation of the magnetic field sensor.

[0015] Compared to the conventionally used wires through which current flows and which are brought near the magneto-optical material, the use of a resonator structure has the advantage that the microwave field can be generated very efficiently. Accordingly, the microwave source can have a lower power and correspondingly smaller dimensions, so that the magnetic field sensor can be designed compactly.

[0016] According to an embodiment of the invention, the bottom surface and the four side surfaces are formed on a housing, in particular a one-piece housing, wherein the housing has a dielectric at least on the bottom surface and the resonator structure is arranged on the bottom surface. In order to close the housing, a separate cover is provided, on the side of which facing the magnetic field sensor a cover surface is provided. In this embodiment of the invention, the four side surfaces, the bottom surface and the cover surface form a closed space. The housing can be constructed completely or partially from a dielectric, for example from a dielectric plastic. The use of a housing facilitates the production of the magnetic field sensor, since such a housing, a so-called encapsulation, can be obtained simply and advantageously.

[0017] According to an extension of the invention, the magnetic field sensor has a closure, in particular a one-piece closure, wherein the cover surface and the four side surfaces are formed on the closure. In this case, the bottom surface can be constructed on a first dielectric substrate. The resonator structure is arranged in particular on the bottom surface, in this case on the first dielectric substrate. The first dielectric substrate has a dielectric, or is completely or partially constructed of a dielectric, for example, of a dielectric plastic. In this extension of the invention, the four side surfaces, the bottom surface and the cover surface also form the closed space. Such a closure can also be obtained simply and cost-effectively, so that such a magnetic field sensor can be manufactured simply and cost-effectively.

[0018] According to an extension of the present invention, the housing or the first dielectric substrate is arranged on a circuit board. Here, a gap can be arranged between the circuit board and the housing or between the circuit board and the first dielectric substrate. The gap can be filled with air or a dielectric material. Arranging the housing or the first dielectric substrate on the circuit board enables simple contact connection of the components of the magnetic field sensor arranged in a closed space and simple assembly of the magnetic field sensor.

[0019] The thickness of the gap can influence the wave impedance of the resonator and the propagation speed of the microwave field, thereby in turn influencing the resonant frequency. Here, only a small change in the thickness of the gap can change the resonant frequency very drastically - to the point where the resonant frequency of the magnetic field sensor can no longer be operated meaningfully.

[0020] The housing or the first dielectric substrate can also be arranged directly on the printed circuit board. This allows simple and cost-effective production of the magnetic field sensor.

[0021] According to an extension of the present invention, the resonator structure is surrounded by a third metal layer, which is also arranged on the dielectric. The third metal layer can be arranged so that the resonator structure is completely or partially surrounded by the third metal layer towards the four sides. Here, the third metal layer can be connected to the electrical ground of the microwave source. By arranging the third metal layer around the resonator structure on the dielectric, the sensitivity of the resonant frequency to the thickness of the gap can be reduced.

[0022] According to an extension of the present invention, the resonator structure is arranged on the side of the first dielectric substrate facing the closed space, and the first metal layer is arranged on the opposite side of the first dielectric substrate. In particular, the first dielectric substrate is arranged in a housing, wherein the first metal layer is arranged on the side of the first dielectric substrate facing the bottom surface of the housing, and the resonator structure is arranged on the side of the dielectric substrate facing away from the bottom surface of the housing (and therefore facing the closed space). In this extension of the present invention, the side of the dielectric substrate facing away from the bottom surface, the four side walls and the cover surface constructed on the cover form the closed space. Here, the first dielectric substrate can be completely or partially composed of a dielectric, for example, a dielectric plastic. Such a configuration can achieve simple assembly and thus a cost-effective configuration of the magnetic field sensor.

[0023] In an extension of the invention, the second metal layer is arranged on the second dielectric substrate. In this case, the second dielectric substrate is arranged in particular on the cover surface of the cover, wherein the second metal layer is arranged on the side of the second dielectric substrate facing away from the cover surface (and thus facing the enclosed space). Additionally or alternatively, the fourth metal layer can be arranged opposite the second metal layer - and thus can be arranged on the side of the second dielectric substrate facing the cover surface. Such a configuration allows for simple assembly and therefore a cost-effective configuration of the magnetic field sensor.

[0024] In one embodiment of the invention, the first metal layer is designed as a cooling block. This allows a particularly compact design of the magnetic field sensor, since an additional cooling block or an additional metal layer can be omitted.

[0025] In an extension of the invention, the fifth metal layer is arranged parallel to one of the sides of the enclosed space. This improves the shielding of the microwave field amplified by the resonator structure. The fifth metal layer can be electrically connected to the second and / or first metal layer and / or another metal layer, for example, via a contact.

[0026] The resonator structure can be produced by means of a laser, for example by laser structuring. This makes it possible to produce the resonator structure simply, precisely and cost-effectively.

[0027] Further advantages and embodiments of the invention emerge from the description and the accompanying drawings.

[0028] The invention is schematically illustrated in the drawings based on exemplary embodiments and is described below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A magnetic field sensor according to an embodiment of the present invention is shown, wherein a magneto-optical material, an excitation light source, a detector and a resonator structure are arranged on a dielectric in a closed space;

[0030] Figure 2 A further embodiment of the magnetic field sensor according to the present invention is shown, wherein the magneto-optical material, the excitation light source, the detector and the resonator structure are arranged on the bottom surface of the housing, wherein a metal layer is arranged below the bottom surface of the housing;

[0031] Figure 3 Also shown are further embodiments of the magnetic field sensor according to the invention, in which the magneto-optical material, the excitation light source, the detector and the resonator structure are arranged on a first dielectric substrate;

[0032] Figure 4 Likewise shown are further exemplary embodiments of a magnetic field sensor according to the invention, wherein, in addition to the first dielectric substrate, the magnetic field sensor also has a second dielectric substrate;

[0033] Figure 5 A further embodiment of the magnetic field sensor according to the invention is shown, in which a metal layer is provided which is designed as a cooling block;

[0034] Figure 6 A further embodiment of a magnetic field sensor according to the invention is shown, wherein the magnetic field sensor has a metal layer on its side surfaces;

[0035] Figure 7 A further exemplary embodiment of a magnetic field sensor according to the invention is shown, in which the metal layer on the side surfaces is connected to the metal layer on the bottom surface and the cover surface;

[0036] Figure 8 One embodiment of a magnetic field sensor is shown in a top view. DETAILED DESCRIPTION

[0037] Figure 1 A magnetic field sensor 1 is shown, wherein a magneto-optical material 2, such as diamond with NV defects, as well as an excitation light source 3 and a detector 5 are arranged on a dielectric 7, wherein the magneto-optical material is, for example, diamond with NV defects, and the excitation light source is, for example, a laser diode. In addition, a resonator structure 8 is arranged on the dielectric. The resonator structure is configured to amplify and deform the alternating electromagnetic field generated by the microwave source in a predefined frequency band, so that a uniform microwave field is constructed in the region of the magneto-optical material 2. Figure 1 The field lines of the microwave field 41 can be seen in FIG. The first metal layer 11 can be arranged on the bottom side of the dielectric 7. Here, the excitation light source 3, the magneto-optical material 2 and the detector 5 are arranged in a closed space.

[0038] The excitation light source 3 is configured to emit excitation radiation having a wavelength between 490 nm and 575 nm. If the magneto-optical material 2 is irradiated with the excitation radiation, the electronic state of the magneto-optical material 2 can be excited, and the electronic state relaxes again to the ground state while emitting fluorescence radiation. Now, if the spin state of the magneto-optical material 2 is simultaneously excited by a microwave field having a suitable frequency (e.g. 2.87 MHz), the intensity of the emitted fluorescence radiation decreases, because the probability of the ground state being occupied is small: excitation into the excited state proceeds from the ground state. The intensity of the fluorescence radiation can be detected by means of a detector 5.

[0039] An alternating electromagnetic field is generated by means of a microwave source, and the alternating electromagnetic field is amplified and deformed by a resonator structure 8 arranged on a dielectric 7, so that a microwave field 41 exists at a location where the magneto-optical material 2 is arranged. The first metal layer 11 limits the microwave field 41 downward 13, but does not limit the microwave field 41 upward 12, so that the microwave field can freely propagate upward. This results in that the characteristics of the microwave field 41 generated by the resonator structure 8 can be affected by the environment of the magnetic field sensor 1 and the magnetic field sensor 1 cannot be used universally. In addition, components arranged outside the magnetic field sensor 1 can also be disturbed by the generated microwave field 41, so that such a magnetic field sensor 1 does not meet the requirements in terms of electromagnetic compatibility.

[0040] Furthermore, the optical and electro-optical components 2, 3, 5, 8 of the magnetic field sensor 1 are exposed to ambient conditions. This is particularly problematic for the excitation light source 3. If the excitation light source is designed as a laser diode, it is primarily the facets of the laser diode that are sensitive to organic deposits.

[0041] Figure 2 FIG. 1 shows a magnetic field sensor according to an embodiment of the present invention. A resonator structure 8, a magneto-optical material 2 (e.g., a diamond crystal with NV defects), an excitation light source 3 (e.g., a laser diode), and a detector 5 are arranged on the bottom surface 14 of the housing 17. In addition, the housing 17 has four side surfaces and a bottom surface 14. Figure 2 15 and 16 of the four sides are shown. The housing 17 can be constructed in one piece and have the dielectric 7 at least on the bottom surface 14. The housing 17 can also be formed completely or almost completely by the dielectric 7. The resonator structure 8 can be arranged directly on the bottom surface 14, in particular directly on the dielectric 7.

[0042] The first metal layer 10 can be arranged below the bottom surface 14 of the housing 17, in particular parallel to the bottom surface 14, and thus below the resonator structure 8. The second metal layer 11 can be arranged above the resonator structure 8, in particular on the side of the cover surface 18 facing the component of the magnetic field sensor 2, 3, 5, 8. The microwave field 41 is formed, which is shielded by the first and second metal layers 10, 11 from the upper side 12 and the lower side 12 of the closed space 9, which is formed by the cover surface 18, the four side walls 15, 16 and the bottom surface 14. It should be understood that only a single metal layer (10, 27, 30) can also be arranged below the bottom surface 14 of the housing 17, wherein sufficient shielding and deformation of the microwave field can already be achieved by providing this metal layer.

[0043] The cover surface 18 is formed on the cover 33 so that the cover 33 and the housing 17 close the closed space 9 to the outside, in which the excitation light source 3, the detector 5, the magneto-optical material 2 and the resonator structure 8 are arranged. In this way, the excitation light source 3 and the detector 5 are protected from environmental influences, such as pollution. At the same time, the resonator structure 8 can be arranged in the vicinity of the magneto-optical material 2 so that the microwave field generated by the resonator structure 8 can be transmitted to the magneto-optical material 2 without loss or almost without loss.

[0044] like Figure 2 As shown, the resonator structure 8 can also be surrounded by a third metal layer 20, which is arranged on the bottom surface 14. The housing 17 can be arranged on the circuit board 24, and in particular, the housing 17 can be soldered to the circuit board 24. Here, a gap 25 is generated between the circuit board 24 and the housing 17. The gap 25 can be filled with air or filled with a preferably dielectric material. If the metal layers 10 and 27 are missing, the thickness of the gap 25 between the housing 17 and the circuit board 24 can affect the wave impedance of the resonator formed by the resonator structure 8, the dielectric 7 and the first and second metal layers 11 and 30, as well as the propagation speed of the formed wave and thus the resonant frequency of the resonator. Providing the third metal layer 20 can reduce the sensitivity of the resonant frequency to changes in the thickness of the gap 25.

[0045] Underneath or instead of first metal layer 10, one or more further metal layers 27 may be arranged in housing 17, in particular parallel to bottom surface 14 of housing 17. Alternatively or additionally, metal layer(s) 27 may also be applied to the outside of housing 17. Similarly, underneath or instead of second metal layer 11, further metal layers 28, 29 may be arranged in cover 33, in particular parallel to bottom surface 14 and / or to cover surface 18, or may be arranged on the side of cover 33 facing away from the components of sensors 2, 3, 5, 8, i.e. on the outside of cover 33.

[0046] Metal layers 30, 31, 32 may also be provided on the circuit board 24. These metal layers 30, 31, 32 may be arranged on one side or both sides and / or in the circuit board 24. A microwave source 4 and a magnetic field generating device 6 may also be arranged in the circuit board 24, the microwave source being connected to the resonator structure 8. Here, the magnetic field generating device 6 may include a Helmholtz coil and / or one or more permanent magnets, which generate a permanent magnetic field in the region of the magneto-optical material 2.

[0047] The metal layers 10 , 11 , 27 , 28 , 29 , 30 , 31 , 32 can be designed as ground planes, wherein they are connected to an electrical ground of the microwave source 4 .

[0048] Figure 3 A further exemplary embodiment of a magnetic field sensor 1 is shown. Figure 2 Different from the embodiment in the embodiment, the four side surfaces 15, 16 and the cover surface 18 of the closed space 9 are formed on the sealing member 19, and the excitation light source 3, the detector 5, the magneto-optical material 2 and the resonator structure 8 are arranged in the closed space. The bottom surface 14 is constructed on the first dielectric substrate 21. The first dielectric substrate 21 has a dielectric 7. The sealing member 19 is directly arranged on the first dielectric substrate 21. As in the embodiment according to Figure 2 As in the embodiment of FIG. 1 , here, the excitation light source 3, the detector 5, the resonator structure 8, the magneto-optical material 2 and the third metal layer 20 are also arranged on the bottom surface 14. The third metal layer 20 surrounds the resonator structure 8.

[0049] First metal layer 10 can be arranged in dielectric substrate 21. Second metal layer 11 can be arranged on cover surface 18 of closure 17 so that it faces components 2, 3, 5, 8 of magnetic field sensor 1. Further metal layers 28, 29 are arranged in or on closure 17 or parallel to cover surface 18. Figure 2 Similar to the embodiments described in the context of Figure 3Not shown in the figure - on the circuit board 24.

[0050] Figure 4 Another embodiment of the magnetic field sensor 1 according to the present invention is shown. In this embodiment, a first dielectric substrate 21 and a second dielectric substrate 22 are arranged in a housing 17. Here, the first metal layer 10 is arranged on the bottom surface 14 of the housing 17, and the first dielectric substrate 21 is arranged on the first metal layer 10. The resonator structure 8 and optionally also the third metal layer 20 are arranged on the first dielectric substrate 21.

[0051] On the cover surface 18 of the cover 33, a fourth metal layer 23 is arranged in the closed space 9, and a second dielectric substrate 22 is arranged on the side of the fourth metal layer facing the closed space 9. A second metal layer 11 is arranged on the side of the second dielectric substrate 22 facing the closed space 9. In this embodiment, the dielectric 7 is formed by the first dielectric substrate 21. Figure 2 Similar to the embodiment described in the context of Figure 4 Not shown in the figure - on the circuit board 24.

[0052] Figure 5 A further embodiment of the magnetic field sensor 1 is shown. Figure 2 As in the embodiment of the present invention, the resonator structure 8, the excitation light source 3, the detector 5 and the magneto-optical material 2 are arranged on the bottom surface 14 of the shell 17. The third metal layer 20 can also be arranged on the bottom surface 14 of the shell 17. A second metal layer 11 is arranged on the covering surface 18 of the cover 33. The first metal layer 10 is arranged in the shell 17, in particular arranged below the bottom surface 14 in parallel with the bottom surface 14, and is constructed as a cooling block 25. The cooling block 25 can be constructed of an electrically conductive material. The cooling block 25 can be connected to the electrical ground of the microwave source 4 and can be used as a shield and / or as a ground plane. Figure 2 Similar to the embodiment described in the context of FIG. 1 , in this embodiment, the housing 17 can also be arranged at—at Figure 5 Not shown in the figure - on the circuit board 24.

[0053] Figure 6Another embodiment of the magnetic field sensor 1 is shown. Therein, the resonator structure 8, the excitation light source 3, the detector 5 and the magneto-optical material 2 are again arranged on the bottom surface 14 of the housing 17. The third metal layer 20 can also be arranged on the bottom surface 14 of the housing 17. The second metal layer 11 is arranged in or on the cover 33, in particular parallel to the covering surface 18. The first metal layer 10 is arranged in the housing 17, in particular parallel to the bottom surface 14 and below the bottom surface 14. A fifth metal layer 26 is arranged on at least one of the side surfaces 15 and 16. Further metal layers 34 and 35 can be arranged in the housing 17 or the closure 19 or on the outer side of the housing 17 or the closure 19, respectively, parallel to one of the side surfaces 15 and 16. The metal layers 26, 34 and 35 further shield the microwave field from the environment of the magnetic field sensor 1. In Figure 2 Similar to the embodiment described in the context of FIG. 1 , in this embodiment, the housing 17 can also be arranged at—at Figure 6 Not shown in the figure - on the circuit board 24.

[0054] Figure 7 Further exemplary embodiments of magnetic field sensors 1 are shown. Figure 7 The embodiment in corresponds to the Figure 6 Embodiments in which the metal layers 26, 34, 35 arranged parallel to one of the side surfaces 15, 16 are connected to the metal layers 10, 27 extending parallel to the bottom surface 14 and arranged on or in the housing 17 and / or to the metal layers 11, 28, 29 arranged on or in the cover 33. The metal layers 26, 34, 35 arranged parallel to one of the side surfaces 15, 16 can be connected in a conductive manner to the metal layers 11, 28, 29 extending in or on the cover 33 via the contacts 36, 37, 38.

[0055] It is understood that in an embodiment in which the side surfaces 15, 16 and the cover surface 17 are arranged on the closure 19 and the bottom surface 14 is formed on the dielectric substrate 21, a metal layer 26, 34, 35 arranged parallel to one of the side surfaces 15, 16 may be provided, in this case arranged in the closure 19. The metal layer 26, 34, 35 arranged parallel to one of the side surfaces 15, 16 may also be connected in an electrically conductive manner to the metal layer 10, 27 arranged in or on the dielectric substrate 21 and / or to the metal layer 11, 28, 29 extending parallel to the cover surface 18 and arranged in the closure 19. In this case, the metal layer 10, 27 arranged in or on the dielectric substrate 21 is electrically connected to the metal layer 26, 34, 35 arranged parallel to one of the side surfaces 15, 16 via the contact elements 26, 27, 28.

[0056] Figure 8An embodiment of the magnetic field sensor 1 is shown in a top view. The resonator structure 8, the excitation light source 3 and the magneto-optical material 2 are arranged on the bottom surface 14 of the housing 17. Figure 8 The cover 33 is not shown in the figure, which together with the housing 17 closes the closed space to the outside. The resonator structure 8 has a horseshoe-shaped first part 39 and an annular second part 40, wherein the horseshoe-shaped first part 39 and the annular second part 40 have a gap, and the two parts 39 and 40 are connected to each other at the corresponding edges of the gap. The magneto-optical material 2 is arranged at the center point of the annular second part 40, in this case, a diamond with NV defects. The housing 17 is arranged on the circuit board 24. The magnetic field generating device 6 is also arranged on the circuit board 24, and the magnetic field generating device is constructed as an arrangement of four permanent magnets.

Claims

1. A magnetic field sensor (1) having - magneto-optical material (2), - an excitation light source (3) configured to emit excitation radiation for exciting electronic states of the magneto-optical material (2), a microwave source (4) which is designed to generate an electromagnetic field for feeding the resonator structure (8), a detector (5) which is designed to detect fluorescence radiation emitted by the magneto-optical material (2) after irradiation with the excitation radiation, a magnetic field generating device (6) arranged and constructed to generate a permanent magnetic field in the region of the magneto-optical material (2), a resonator structure (8) arranged on the dielectric (7), the resonator structure being designed to deform the electromagnetic field emitted by the microwave source (4) so ​​as to generate a microwave field suitable for manipulating the spin state of the magneto-optical material (2), -in, The magneto-optical material (2), the excitation light source (3), the detector (5) and the resonator structure (8) are arranged in a closed space (9).

2. The magnetic field sensor (1) according to claim 1, wherein: A first metal layer (10) is arranged below the resonator structure (8), which is arranged on the dielectric (7), and / or a second metal layer (11) is arranged above the resonator structure (8), which is arranged on the dielectric (7), and the first and / or second metal layers (10, 11) are constructed to shield a microwave field originating from the microwave structure (8) from an upper side (12) and a lower side (13) of the closed space (9).

3. The magnetic field sensor (1) according to claim 1, wherein: The bottom surface (14) and four side surfaces (15, 16) of the closed space (9) are formed on a housing (17), wherein the housing (17) has a dielectric (7) at least on the bottom surface (14).

4. The magnetic field sensor (1) according to claim 1, wherein: A cover surface (18) and four side surfaces (15, 16) of the closed space (9) are formed on a closure element (19), wherein the bottom surface (14) is formed on a first dielectric substrate (21).

5. The magnetic field sensor (1) according to claim 2 or 3, wherein: The resonator structure (8) is arranged on the bottom surface (14) of the closed space (9).

6. The magnetic field sensor (1) according to any one of the preceding claims, wherein: The first and / or second metal layer (10, 11) is configured as a ground plane which is connected to a ground of the microwave source (4).

7. The magnetic field sensor (1) according to any one of the preceding claims, wherein: The resonator structure (8) is surrounded by a third metal layer (20), which is also arranged on the dielectric (7).

8. The magnetic field sensor (1) according to any one of the preceding claims, wherein: The resonator structure (8) is arranged on the first dielectric substrate (21) opposite the first metal layer (10).

9. The magnetic field sensor (1) according to any one of the preceding claims, wherein: The second metal layer (11) is arranged on a second dielectric substrate (22).

10. The magnetic field sensor (1) according to claim 8, wherein: A fourth metal layer (23) is arranged on the second dielectric substrate (22) opposite the second metal layer (11).

11. The magnetic field sensor (1) according to any one of the preceding claims, wherein: The housing (17) or the first dielectric substrate (21) is arranged on a circuit board (24).

12. The magnetic field sensor (1) according to claim 10, wherein: A gap (25) is arranged between the printed circuit board (24) and the housing (17) or the first dielectric substrate (21), wherein the gap is filled with air or a dielectric material.

13. The magnetic field sensor (1) according to any one of the preceding claims, wherein: The first metal layer (10) is configured as a cooling block (25).

14. The magnetic field sensor (1) according to any one of the preceding claims, wherein: The fifth metal layer (26) is arranged parallel to one of the side surfaces (15, 16) of the closed space (9).

15. The magnetic field sensor (1) according to claim 13, wherein: The fifth metal layer (26) electrically connects the first metal layer (10) and the second metal layer (11).

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