Diamond sensor unit

Abstract

A diamond sensor unit includes: a diamond having a color center with an electron spin; an excitation light irradiation section that irradiates the diamond with excitation light; a first patch antenna that receives an electromagnetic wave; an electromagnetic wave irradiation section that irradiates the diamond with the electromagnetic wave received by the first patch antenna; a detection section that detects emission light emitted from the color center of the diamond after the excitation light and the electromagnetic wave are irradiated to the diamond; and an optical waveguide that transmits the excitation light and the emission light.

Description

Technical Field

[0001] This disclosure relates to diamond sensor units. This application claims priority based on Japanese Application No. 2021-010937, filed on January 27, 2021, and incorporates the entire contents of that Japanese application. Background Technology

[0002] Sensors using diamond NV centers are known. In cases where diamond NV centers are combined with microscopes, for example... Figure 1 The configuration is shown. Specifically, the LED 900, disposed on substrate 912, emits green light to excite the NV center of diamond 904. The emitted light, after passing through SPF (Short Pass Filter) 902, is incident on diamond 904 disposed on substrate 914. Thus, NV... - The central electron becomes excited. When the excited electron returns to its original ground state, red fluorescence is emitted from the diamond 904. This fluorescence is focused by lens 906 and, after passing through LPF (Long Pass Filter) 908, is detected by photodiode 910 disposed on substrate 916. Additionally, microwaves generated by an external device (not shown) are irradiated onto the diamond 904. Thus, if excited to different spin states and resonance states, the intensity of the red fluorescence from the diamond 904 changes. This change is detected by photodiode 910. Lens 906 can be a lens structure of a high-performance optical microscope or a simple lens structure.

[0003] Patent Document 1 discloses a scanning probe microscope (i.e., frequency-modulated atomic force microscope (FM-AFM)) using a diamond NV center. Patent Document 2 discloses a magnetic field detection device using a diamond NV center. Non-Patent Document 1 discloses a compact magnetic field detection device using a lens.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-67650

[0007] Patent Document 2: Japanese Patent Application Publication No. 2018-136316

[0008] Non-patent literature

[0009] Non-patent literature 1: Felix M. Stuerner, et al., “Compact integrated magnetometer based on nitrogen-vacancy centers in diamond”, Diamond & RelatedMaterials 93 (2019) 59-65 Summary of the Invention

[0010] The diamond sensor unit disclosed herein includes: a diamond having a color center with an electron spin; an excitation light irradiation unit for irradiating the diamond with excitation light; a first patch antenna for receiving electromagnetic waves; an electromagnetic wave irradiation unit for irradiating the diamond with electromagnetic waves received by the first patch antenna; a detection unit for detecting emitted light from the color center of the diamond after the diamond is irradiated with excitation light and electromagnetic waves; and an optical waveguide for transmitting the excitation light and emitted light. Attached Figure Description

[0011] Figure 1 This is a cross-sectional view of an existing NV center microscope that uses diamond.

[0012] Figure 2 This is a schematic diagram showing the general structure of the diamond sensor unit according to the first embodiment of this disclosure.

[0013] Figure 3 This is a three-dimensional view showing a patch antenna for receiving microwaves.

[0014] Figure 4 This is a three-dimensional view showing a horn antenna that transmits microwaves.

[0015] Figure 5 It shows that it was used Figure 2 The timing diagram shows the timing of the excitation light and electromagnetic wave irradiation, as well as the timing of the emission light measurement, for the diamond sensor unit shown.

[0016] Figure 6 It is a graph that schematically shows the relationship between the observed signal strength (i.e., the intensity of emitted light) and the frequency of electromagnetic waves (i.e., microwaves).

[0017] Figure 7 This is a schematic diagram showing the general structure of the diamond sensor unit according to the second embodiment of this disclosure.

[0018] Figure 8 This is a three-dimensional view showing the configuration of the micropatch antenna and the horn antenna on the object being measured.

[0019] Figure 9 It shows along including Figure 8The diagram shows a cross-sectional view of the object being measured, the micropatch antenna, and the horn antenna formed by cutting the plane along the IX-IX line.

[0020] Figure 10 This illustrates the second embodiment (see reference). Figure 7 A perspective view of an embodiment of ).

[0021] Figure 11 This is a perspective view showing an electromagnetic wave irradiation section that uses coplanar circuitry.

[0022] Figure 12A It is a graph showing the experimental results.

[0023] Figure 12B It is a graph showing the experimental results.

[0024] Figure 12C It is a graph showing the experimental results.

[0025] Figure 13 It is a graph showing the experimental results. Detailed Implementation

[0026] [The technical problem the invention aims to solve]

[0027] When using sensors on high-voltage equipment such as power equipment, there is a possibility of damage to the light-emitting and light-receiving elements due to the instantaneous high voltage and current generated by discharge, or due to the strong electromagnetic waves generated as a result. Therefore, the structure disclosed in Patent Document 1 cannot be used in sensors used in high-voltage environments.

[0028] Patent document 2 discloses a configuration in which the light-emitting element and the light-receiving element are positioned away from the diamond and microwave irradiation coil. However, since the excitation light and the emitted fluorescence are transmitted in the air as parallel light, they diffuse, and the distance they can be moved away is limited. In particular, the weak signal intensity of the fluorescence becomes a problem.

[0029] Therefore, the purpose of this disclosure is to provide a diamond sensor unit that is not damaged even in high-voltage environments and can accurately detect magnetic fields and the like over long distances.

[0030] [The effects of the invention]

[0031] According to this disclosure, a diamond sensor unit can be provided that is not damaged even in high-voltage environments and can accurately measure magnetic and electric fields over long distances.

[0032] [Description of embodiments of this disclosure]

[0033] The embodiments described herein are listed below. At least a portion of the embodiments described below may also be combined in any way.

[0034] (1) The diamond sensor unit according to the first aspect of this disclosure includes: a diamond having a color center with electron spin; an excitation light irradiation unit for irradiating the diamond with excitation light; a first patch antenna for receiving electromagnetic waves; an electromagnetic wave irradiation unit for irradiating the diamond with electromagnetic waves received by the first patch antenna; a detection unit for detecting emitted light from the color center of the diamond after the diamond is irradiated with excitation light and electromagnetic waves; and an optical waveguide for transmitting the excitation light and emitted light. Therefore, it will not be damaged even in high-voltage environments, and can accurately measure magnetic and electric fields over long distances. Furthermore, by using a patch antenna as the receiving antenna for electromagnetic waves, the design freedom is increased.

[0035] (2) The diamond sensor unit may also include a horn antenna or a second patch antenna for transmitting electromagnetic waves received by the first patch antenna. The horn antenna can transmit microwaves as electromagnetic waves, and the second patch antenna can transmit microwaves, millimeter waves, or submillimeter waves as electromagnetic waves. This allows for the transmission of electromagnetic waves with good directivity to the first patch antenna, improving detection accuracy. Furthermore, it can transmit electromagnetic waves at frequencies corresponding to the type of color center used, and is not limited to NV centers; it can also realize sensors using Si-V centers, Ge-V centers, or Sn-V centers, etc.

[0036] (3) The first patch antenna may also include a plate-shaped conductive component for receiving electromagnetic waves, disposed on the electrical equipment or electrical wiring to be detected. The first patch antenna may also be configured such that the conductive component is parallel to the equipotential surface formed by the object being detected. Thus, when receiving electromagnetic waves by the first patch antenna, the influence of the electric field generated by the normal operation of the electrical equipment or electrical wiring to be measured can be suppressed. Therefore, the first patch antenna can stably receive electromagnetic waves.

[0037] (4) The equipotential surface can also be curved, and the first patch antenna can also be configured such that the conductive component follows the curved shape. Therefore, when receiving electromagnetic waves by the first patch antenna, the influence of the electric field generated by the normal operation of the electrical equipment or electrical wiring passing through the object being measured can be further suppressed. Thus, the first patch antenna can receive electromagnetic waves more stably.

[0038] [Details of the embodiments of this disclosure]

[0039] In the following embodiments, the same reference numerals are used to refer to the same parts. Their names and functions are also the same. Therefore, detailed descriptions of them will not be repeated.

[0040] (First Implementation)

[0041] Reference Figure 2The diamond sensor unit 100 according to the first embodiment of this disclosure includes an excitation light generating unit 106, a fluorescence reflection filter 110, an optical waveguide 112, a sensor unit 120, an LPF 122, a light receiving unit 128, and a receiving unit 130. An electromagnetic wave generating unit 140, a control unit 142, and a transmitting unit 144 are disposed outside the diamond sensor unit 100.

[0042] The control unit 142 includes a CPU (Central Processing Unit) and a storage unit (neither shown). The processing performed by the control unit 142, which will be described later, is achieved by the CPU reading and executing programs pre-stored in the storage unit.

[0043] The excitation light generating unit 106 includes a light-emitting element 102 and a light-concentrating element 104. The light-emitting element 102 is controlled by the control unit 142 to generate NV light for exciting the diamond (described later). - The excitation light is emitted from the center (hereinafter referred to as the NV center). The control unit 142 supplies a voltage to the light-emitting element 102 at a predetermined timing, for example. The excitation light is green light (wavelength approximately 490-560 nm). The excitation light is preferably a laser, and the light-emitting element 102 is preferably a semiconductor laser (e.g., the wavelength of the emitted light is 532 nm). The focusing element 104 focuses the excitation light emitted from the light-emitting element 102. The focusing element 104 is a component for inputting as much of the excitation light diffused and emitted from the light-emitting element 102 as possible into the incident end of the optical waveguide 112, which will be described later. The focusing element 104 preferably outputs parallel light focused within a range smaller than the size of the incident end of the optical waveguide 112 (e.g., its core diameter (i.e., the diameter of the fiber core) in the case of using an optical fiber).

[0044] The fluorescence reflection filter 110 is an element used to separate the excitation light incident from the focusing element 104 from the light emitted from the diamond (i.e., fluorescence), as described later. For example, the fluorescence reflection filter 110 is a short-pass filter that allows light with wavelengths below a specified wavelength to pass through and blocks (i.e. reflects) light with wavelengths higher than the specified wavelength, or a band-pass filter that allows light with wavelengths within a specified wavelength range to pass through and blocks (i.e. reflects) light with wavelengths outside the specified wavelength range. Generally, since the wavelength of the excitation light is shorter than that of the fluorescence, such a structure is preferred. The fluorescence reflection filter 110 is preferably a dichroic mirror with this function.

[0045] The optical waveguide 112 includes a medium for transmitting light, enabling bidirectional light transmission. Specifically, it transmits excitation light incident on the first end disposed on the excitation light generating section 106 to the second end disposed on the sensor section 120. Additionally, it transmits emitted light (i.e., fluorescence) incident on the diamond element 116 at the second end to the first end. The optical waveguide 112 is, for example, an optical fiber. To increase the energy density of the transmitted excitation light, it is preferable that the core diameter of the optical fiber be as small as possible. On the other hand, if the core diameter is too small, the efficiency of inputting light diffused and emitted from the light source (i.e., the light-emitting element) into the optical fiber decreases. Therefore, an appropriate core diameter exists. For example, the core diameter of the optical fiber is approximately 80µm or less and 1µm or more.

[0046] The sensor unit 120 includes a focusing element 114, a diamond element 116, and an electromagnetic wave irradiation unit 118. The diamond element 116 includes an NV center. The focusing element 114 is disposed in contact with the diamond element 116. The focusing element 114 focuses the excitation light output from the optical waveguide 112 and irradiates the diamond element 116. The electromagnetic wave irradiation unit 118 irradiates electromagnetic waves (e.g., microwaves) onto the diamond element 116. The electromagnetic wave irradiation unit 118 is, for example, a coil formed including an electrical conductor. The source of the electromagnetic waves irradiated from the electromagnetic wave irradiation unit 118 onto the diamond element 116 is the electromagnetic wave generating unit 140. That is, the electromagnetic waves output from the electromagnetic wave generating unit 140 are radiated into the air as electromagnetic waves EW by the transmitting unit 144, received by the receiving unit 130 (e.g., an antenna), and transmitted to the electromagnetic wave irradiation unit 118.

[0047] The receiving unit 130 is, for example, Figure 3 The patch antenna shown is a microstrip antenna. This patch antenna includes substrates 280 and 284, and a connector 288 for outputting the received signal. Connector 288 is an SMA-type coaxial connector, connected to the electromagnetic wave irradiation unit 118 via a coaxial cable or the like. Substrates 280 and 284 are arranged at a predetermined interval H by spacers 286 at their four corners. Substrates 280 and 284 are both substrates of electrically insulating components with a predetermined thickness d, and their planes are squares with side length L. On the two planes of substrate 280, on the surfaces not opposite substrate 284, four conductive components 282 are arranged far apart from each other. Each conductive component 282 is a square, with its four sides parallel to the four sides of substrate 280, and the four conductive components 282 as a whole are symmetrical about the center point of substrate 280. On the entire surface of the two planes of substrate 284 opposite substrate 280, conductive components 290 are arranged.

[0048] Four conductive parts 282 are connected in parallel with the signal lines of connector 288, and the conductive part 290 of substrate 284 is connected to the shield (i.e., ground) of connector 288. Conductive part 290 is the ground plane of patch antenna. Thus, patch antenna is directional in a direction perpendicular to the plane of substrate 280. Microwaves received by receiving unit 130 are transmitted to electromagnetic wave irradiation unit 118 via transmission path (i.e., coaxial cable) and irradiate diamond element 116. In the case of receiving microwaves at a frequency of approximately 2.87 GHz, substrates 280 and 284 are made, for example, of glass epoxy resin substrates (e.g., FR4) with L=120 (mm) and t=1 (mm) and arranged at intervals of H=5.2 (mm). Patch antenna can be formed in a planar shape, thus increasing the design freedom by using patch antenna in receiving unit 130.

[0049] For example, the sending unit 144 is Figure 4 The waveguide horn antenna shown is a waveguide antenna. The horn antenna includes an adapter section 300, a horn section 302, and a connector 304. The connector 304 is an SMA-type coaxial connector that supplies electromagnetic waves (i.e., microwaves) from an external source (i.e., the electromagnetic wave generator 140) to the adapter section 300. The adapter section 300 is a waveguide formed of a conductive material (e.g., aluminum alloy), and the shape of its cross-section (hereinafter referred to as the cut) perpendicular to the propagation direction of the electromagnetic wave is constant. The electromagnetic waves supplied to the adapter section 300 propagate to the horn section 302. The horn section 302 is formed of a conductive material (e.g., aluminum alloy) and is shaped as a hammer with a gradually widening cut to match free space and suppress reflections. The horn antenna is directional in the direction of its central axis 306. Figure 4 The horn section 302 of the horn antenna shown has an opening of a specified width L1 and a specified height L2, and the total length of the adapter section 300 and the horn section 302 is a specified length L3. In the case of microwaves with a transmission frequency of approximately 2.87 GHz, horn antennas with L1 = 110 (mm), L2 = 87.9 (mm), and L3 = 254 (mm) can be used, for example. By using a horn antenna in the transmitting section 144, electromagnetic waves can be transmitted to the receiving section 130 (i.e., patch antenna) with good directivity.

[0050] It should be noted that the shape of the trumpet portion 302 is only required to be a hammer shape with the cut gradually widening, and is not limited to that of other parts. Figure 4The shape shown is arbitrary. For example, the shape of the horn portion 302 can be conical, a pyramidal shape with the height L2 of the opening equal to the height of the adapter portion 300, or a pyramidal shape with the width L1 of the opening equal to the width of the adapter portion 300. Furthermore, the adapter portion 300 and the horn portion 302 can be formed as a single unit or configured to be detachable. For example, each of the adapter portion 300 and the horn portion 302 can have a flange at the connection point, and the flange can be detachably connected by screws or the like. Additionally, the electromagnetic wave outlet (i.e., the opening) of the horn portion 302 should face the receiving portion 130 (i.e., the receiving portion 130 is located on the extension line of the central axis 306 of the horn antenna). The horn portion 302 is preferably separated from the closest part of the patch antenna by at least 50 cm, more preferably by at least 1 m, further preferably by at least 5 m, and even more preferably by at least 10 m. When the distance is less than 50 cm, if the receiving unit 130 is located on a high-voltage side of 33 kV or higher (e.g., a high-voltage device), discharge is likely to occur between the high-voltage side and the speaker unit 302, which is not preferable. Furthermore, when the distance is greater than 30 m, the power of the microwaves emitted from the transmitting unit 144 cannot reach the receiving unit 130, which is also not preferable.

[0051] The irradiation of the diamond element 116 by the excitation light and electromagnetic waves is controlled by the control unit 142, for example, in Figure 5 The timing is as shown. That is, the control unit 142 controls the light-emitting element 102 to output excitation light for a predetermined time (e.g., period t1) at a predetermined time. The control unit 142 controls the electromagnetic wave generating unit 140 to output electromagnetic waves for a predetermined time (e.g., period t2) at a predetermined time. The pulse sequence in period t2 can be any appropriate pulse sequence used depending on the diamond used (e.g., the consistency of the orientation of multiple NV centers) and the observed signal (i.e., the signal affected by the spin state of the NV centers). Thus, the electromagnetic waves and excitation light are combined in time and space to irradiate the diamond element 116. As will be described later, the control unit 142 obtains the output signal of the input light detection unit 126 at a predetermined time (e.g., within period t3) and stores it in the storage unit.

[0052] The NV center has a structure similar to that of a diamond crystal, where carbon (C) atoms are replaced by nitrogen (N) atoms, and no adjacent carbon atoms (i.e., vacancies (V)) are present. The NV center migrates from its ground state to an excited state by emitting green light (e.g., a 532 nm laser) with wavelengths of approximately 490–560 nm, and returns to its ground state by emitting red light (e.g., 637 nm fluorescence) with wavelengths of approximately 630–800 nm. The NV center in a state where it has captured an electron (i.e., NV...) - Under these conditions, the magnetic quantum number m is formed. s Given a spin triplet state of -1, 0, +1, if a magnetic field exists, then ms The energy levels of the ±1 state split according to the magnetic field strength (Zeeman splitting). Irradiating the center of NV with microwaves of approximately 2.87 GHz causes m... s The state =0 transitions to m s After reaching the state of ±1 (i.e., electron spin resonance), it is excited by irradiation with green light. As a result, the intensity of the observed emitted light decreases because the migration back to the ground state includes the migration of non-emissive light (i.e., fluorescence). Therefore, a valley (i.e., a drop in signal) is observed in the ESR (Electron Spin Resonance) spectrum. As described above, the light-emitting element 102 and the electromagnetic wave generating unit 140 are controlled by the control unit 142, for example, to measure... Figure 6 The spectrum shown. The observed Δf depends on the magnetic field strength at the location of diamond element 116.

[0053] The specific spectral measurements are performed as follows. Light diffused and emitted from the diamond element 116 (i.e., fluorescence) is focused by the focusing element 114 and input as parallel light to the second end of the optical waveguide 112. The light (i.e., fluorescence) input into the optical waveguide 112 is transmitted through the optical waveguide 112 and output from the first end of the optical waveguide 112. The light (i.e., fluorescence) output from the first end of the optical waveguide 112 is reflected by the fluorescence reflection filter 110, passes through the LPF 122, is focused by the focusing element 124, and incident on the photodetector 126. Thus, light with a frequency corresponding to the magnetic field at the location where the diamond element 116 is positioned is detected by the photodetector 126. The photodetector 126 generates and outputs an electrical signal corresponding to the incident light. The photodetector 126 is, for example, a photodiode. The output signal of the photodetector 126 is acquired by the control unit 142.

[0054] LPF122 is a long-pass filter that allows light with wavelengths above a specified wavelength to pass through while blocking (e.g., reflecting) light with wavelengths smaller than the specified wavelength. The emitted light from diamond element 116 is red light, which passes through LPF122, but the excitation light, due to its shorter wavelength, does not pass through LPF122. Therefore, it is possible to suppress the excitation light emitted from light-emitting element 102 from being detected as noise by photodetector 126, and to reduce the detection sensitivity of the emitted light (i.e., fluorescence) from diamond element 116.

[0055] Based on the above, the control unit 142 can irradiate excitation light onto the diamond element 116, scan the frequency of electromagnetic waves within a specified range, and irradiate the diamond element 116, thereby acquiring the light (i.e., fluorescence) emitted from the diamond element 116 as an electrical signal output from the photodetector 126. The magnetic field strength at the location of the diamond element 116 can be calculated based on the observed Δf (i.e., the value of the magnetic field strength at the location of the diamond element 116). In other words, the diamond sensor unit 100 functions as a magnetic sensor. It should be noted that the diamond sensor unit 100 is not limited to magnetic fields (i.e., magnetic fields), and can also be used as a sensor for detecting physical quantities related to magnetic fields, such as magnetization, electric field, voltage, current, temperature, and pressure.

[0056] The electromagnetic waves irradiated onto the diamond element 116 are propagated in the air (i.e. wirelessly) by the transmitting unit 144 and the receiving unit 130, and transmitted to the electromagnetic wave irradiation unit 118. Therefore, in high-voltage devices such as those equipped with the sensor unit 120, even if high voltage and large current are generated due to discharge, the device for transmitting electromagnetic waves (i.e., the electromagnetic wave generating unit 140 and the control unit 142) will not be damaged.

[0057] Furthermore, if optical fiber is used in the optical waveguide 112, the diamond element 116 and the focusing element 114, which are the main body of the sensor, are formed of electrical insulators. Therefore, even if the sensor section 120 and the second end of the optical waveguide 112 are provided in a high-voltage device, damage caused by discharge or the like can be suppressed. Thus, the diamond sensor unit 100 can safely measure magnetic fields in a high-voltage environment. In addition, the excitation light generating section 106 and the light receiving section 128 can be arranged away from the high-voltage environment via the optical waveguide 112, and the electromagnetic wave generating section 140 and the transmitting section 144 can also be arranged away from the high-voltage environment. Therefore, the diamond sensor unit 100 can measure magnetic fields at a distance. The distance (i.e., the interval distance) between the transmitting section 144, the excitation light generating section 106, the light receiving section 128 and the sensor section 120 is preferably 10 cm or more, more preferably 50 cm or more. The interval distance is further preferably 1 m or more, even more preferably 5 m or more, and even more preferably 10 m or more.

[0058] Furthermore, since the sensor unit 120 includes a focusing element 114 disposed between the diamond element 116 and the optical waveguide 112, the loss of excitation and emission light can be reduced, thereby improving detection accuracy. Additionally, a fluorescence reflection filter 110 can be provided to separate the excitation and emission light, with both light transmitted through a single medium (e.g., the optical waveguide 112). Therefore, as will be described later, compared to the case where two separate media are used to transmit the excitation and emission light, the number of components can be reduced, resulting in a simpler structure.

[0059] (Second Implementation)

[0060] In the first embodiment, a single optical waveguide 112 is used for bidirectional light transmission (i.e., excitation light and emission light), but in the second embodiment, optical waveguides are used to transmit the excitation light and emission light of the diamond element 116 respectively. (Refer to...) Figure 7 The diamond sensor unit 200 according to the second embodiment of this disclosure includes an excitation light generating unit 206, a first optical waveguide 212, a focusing element 208, a fluorescence reflection filter 210, a sensor unit 220, an LPF 222, a focusing element 224, a second optical waveguide 230, a light receiving unit 228, and a receiving unit 252. Similar to the first embodiment, an electromagnetic wave generating unit 140, a control unit 142, and a transmitting unit 144 are disposed externally on the diamond sensor unit 200.

[0061] The excitation light generating unit 206 includes a light-emitting element 202 and a light-concentrating element 204. The sensor unit 220 includes a light-concentrating element 214, a diamond element 216, and an electromagnetic wave irradiation unit 218. The light receiving unit 228 includes a light detection unit 226. The light-emitting element 202, the light-concentrating element 204, the fluorescence reflection filter 210, the light-concentrating element 214, the diamond element 216, the electromagnetic wave irradiation unit 218, the LPF 222, the light detection unit 226, and the receiving unit 252 are respectively connected to... Figure 2 The light-emitting element 102, the focusing element 104, the fluorescence reflection filter 110, the focusing element 114, the diamond element 116, the electromagnetic wave irradiation unit 118, the LPF 122, the light detection unit 126, and the receiving unit 130 shown below all function similarly. Therefore, they will be described briefly.

[0062] Similar to the first embodiment, the light-emitting element 202 is controlled by the control unit 142 to generate excitation light for exciting the NV center of the diamond. The control unit 142, for example, supplies a voltage to the light-emitting element 202 at a predetermined timing. The excitation light is green light. The excitation light is preferably a laser, and the light-emitting element 202 is preferably a semiconductor laser. The focusing element 204 focuses the excitation light diffused and output from the light-emitting element 202 and inputs it to the incident end of the first optical waveguide 212.

[0063] The first optical waveguide 212 includes a medium for transmitting light. The first optical waveguide 212 and... Figure 2Unlike the waveguide 112 shown, this waveguide transmits excitation light but not the emitted light from the diamond element 216. That is, the excitation light incident on the first waveguide 212, positioned at the first end (i.e., the incident end) on the side of the excitation light generation section 206, is transmitted to the second end (i.e., the output end) positioned on the side of the sensor section 220 and output. The first waveguide 212 is, for example, an optical fiber. The excitation light diffused and output from the first waveguide 212 is focused by the focusing element 208 and incident as parallel light onto the fluorescence reflection filter 210.

[0064] The fluorescence reflection filter 210 is a component used to separate the excitation light incident from the focusing element 208 from the light emitted from the diamond element 216 (i.e., fluorescence). The fluorescence reflection filter 210 can also be a dichroic mirror.

[0065] Concentrating element 214 focuses the excitation light input through fluorescence reflection filter 210 and irradiates diamond element 216. Concentrating element 214 is configured in contact with diamond element 216. Diamond element 216 includes an NV center. Electromagnetic wave irradiation unit 218 irradiates electromagnetic waves (e.g., microwaves) onto diamond element 216. Electromagnetic wave irradiation unit 218 is, for example, a coil. Electromagnetic waves are generated by electromagnetic wave generating unit 140, radiated into the air as electromagnetic waves EW by transmitting unit 144, and received by receiving unit 252 (e.g., Figure 3 The patch antenna shown receives and supplies electromagnetic wave irradiation to the electromagnetic wave irradiation unit 218. The irradiation of the diamond element 216 by the excitation light and electromagnetic waves is controlled by the control unit 142, for example... Figure 5 The timing control is shown. As such, red light (i.e., fluorescence) is emitted from the diamond element 216, as described above.

[0066] The light diffused and emitted from the diamond element 216 (i.e., red fluorescence) is focused into parallel light by the focusing element 214 and input to the fluorescence reflection filter 210. The light (i.e., red fluorescence) input into the fluorescence reflection filter 210 is reflected by the fluorescence reflection filter 210 and incident on the LPF 222. The emitted light (i.e., red fluorescence) from the diamond element 216 incident on the LPF 222 passes through the LPF 222, is focused by the focusing element 224, and incident on the first end (i.e., the incident end) of the second optical waveguide 230. The LPF 222 suppresses the excitation light emitted from the light-emitting element 202 from being detected by the photodetector 226 as noise, thus reducing the detection sensitivity of the emitted light (i.e., fluorescence) from the diamond element 216.

[0067] The second optical waveguide 230 includes a medium for transmitting light. The second optical waveguide 230 transmits light (i.e., the emitted light from the diamond element 216) incident from the focusing element 224 to the first end (i.e., the incident end) to the second end (i.e., the output end) disposed on the light-receiving side of the light-receiving portion 228 and outputs it. The light output from the second optical waveguide 230 is detected by a light detection unit 226. The light detection unit 226 is, for example, a photodiode. The output signal of the light detection unit 226 is acquired by the control unit 142.

[0068] Based on the above, similar to the first embodiment, the control unit 142 can irradiate excitation light onto the diamond element 216, scan the frequency of electromagnetic waves within a predetermined range, and irradiate the diamond element 216, thereby acquiring the light (i.e., fluorescence) emitted from the diamond element 216 as an electrical signal output from the photodetector 226. Therefore, the diamond sensor unit 200 functions as a magnetic sensor. The diamond sensor unit 200 is not limited to magnetic fields, and can also be used as a sensor for detecting physical quantities related to magnetic fields, such as magnetization, electric field, voltage, current, temperature, and pressure.

[0069] The electromagnetic waves irradiated onto the diamond element 216 are propagated in the air (i.e. wirelessly) by the transmitting unit 144 and the receiving unit 252 and transmitted to the electromagnetic wave irradiation unit 218. Therefore, in high-voltage devices such as those equipped with the sensor unit 220, even if high voltage and large current are generated due to discharge, the device for transmitting electromagnetic waves (i.e., the electromagnetic wave generating unit 140 and the control unit 142) will not be damaged.

[0070] Furthermore, if optical fibers are used in both optical waveguides, the diamond element 216 and the focusing element 214, which serve as the main body of the sensor, are formed of electrical insulators, thus suppressing damage caused by discharge, etc. Therefore, the diamond sensor unit 200 can safely measure magnetic fields, etc., in a high-voltage environment. Additionally, the excitation light generating section 206 and the light receiving section 228 can be arranged away from the high-voltage environment via the first optical waveguide 212 and the second optical waveguide 230, and the electromagnetic wave generating section 140 and the transmitting section 144 can also be arranged away from the high-voltage environment. Therefore, the diamond sensor unit 200 can measure magnetic fields, etc., at a distance. The distance (i.e., the interval distance) between the transmitting section 144, the excitation light generating section 206, the light receiving section 228 and the sensor section 220 is preferably 10 cm or more, more preferably 50 cm or more. The interval distance is further preferably 1 m or more, even more preferably 5 m or more, and even more preferably 10 m or more.

[0071] In addition, the sensor unit 220 includes a focusing element 214 disposed between the diamond element 216 and the first optical waveguide 212 and the second optical waveguide 230, which can reduce the loss of excitation light and emission light and improve detection accuracy.

[0072] By using two optical waveguides (i.e., the first optical waveguide 212 and the second optical waveguide 230), excitation light and the emitted light from the diamond element 216 with different wavelengths can be transmitted appropriately, respectively. That is, by using optical fibers with core diameters corresponding to the wavelengths, suitable focusing optical systems (i.e., focusing elements 204, 208, 214, and 224) can be designed, improving light transmission efficiency and measurement accuracy. When using optical fibers in the waveguides, the core diameter of the optical fiber transmitting the emitted light from the diamond (i.e., the second optical waveguide 230) is preferably larger than the core diameter of the optical fiber transmitting the excitation light (i.e., the first optical waveguide 212).

[0073] As described above, to increase the energy density of the excitation light, a smaller core diameter is preferable for the optical fiber used to transmit the excitation light. However, if the core diameter is too small, losses will occur when light is input from the light source into the optical fiber. Therefore, an appropriate core diameter is required. The core diameter of the first optical waveguide 212 is preferably 1µm or more and 100µm or less. On the other hand, a larger core diameter is preferable for the optical fiber used to transmit the emitted light from the diamond element 216. However, if the core diameter is too large, the cost will be high. The core diameter of the second optical waveguide 230 is preferably 1µm or more and 1mm or less.

[0074] Figure 2 The sensor unit 120 and receiver unit 130 are disposed near the object being detected. If the object being detected is a high-voltage electrical device or power transmission line, it generates an electric field around it when energized, thus affecting the receiving performance of the receiver unit 130. (Regarding...) Figure 5 The same applies to the sensor section 220 and the receiver section 252. To mitigate the impact, attention is preferably paid to the configuration of the receiver section 130 for the electric field, that is, the configuration of the conductive components that function as antennas for the receiver section 130. Specifically, in Figure 3 In the case of the patch antenna shown, it is preferable to configure the receiving unit 130 so that the conductive components 282 and 290 are parallel to the equipotential surface formed by electrical equipment and power lines, etc. Therefore, when receiving electromagnetic waves by the receiving unit 130, the influence of the electric field formed by the normal operation of the detection object (i.e., high-voltage power equipment or power lines, etc.) can be suppressed. Thus, the receiving unit 130 can stably receive electromagnetic waves emitted from the transmitting unit 144.

[0075] If the equipotential surface at the location where the receiving unit 130 is configured is planar, then as described above, even if the substrates 280 and 284 of the receiving unit 130 are flat (e.g., a glass epoxy resin substrate), the conductive members 282 and 290 can be configured parallel to the equipotential surface. However, if the equipotential surface is curved, and the substrates 280 and 284 are rigid flat plates, it is not possible to configure the conductive members 282 and 290 along the curved equipotential surface. Therefore, it is preferable to form the shapes of the conductive members 282 and 290, i.e., the shapes of the substrates 280 and 284 that form their bases, into shapes that are curved along the equipotential surface. It should be noted that the equipotential surface of power equipment and transmission lines can be known in advance through simulation or the like based on the shape of the conductive members constituting them. If the conductive members deviate from the equipotential surface, it may cause electric field concentration at the corners of patch antennas, which could become the starting point of insulation failure, or cause equipment failure such as arc discharge during a sudden potential change such as a lightning strike.

[0076] For example, refer to Figure 8 When the sensor unit 120 is disposed on a high-voltage power transmission line having a center conductor 310 and an outer conductor 312, the receiver unit 130 is disposed, for example, near the center conductor 310. The center conductor 310 is formed of a conductive member and is surrounded by an insulating member. The outer conductor 312 is formed of a conductive member and is grounded (i.e., at ground potential). A gas such as SF6 or CO2 may also be filled between the center conductor 310 and the outer conductor 312.

[0077] The equipotential surface formed by energizing the central conductor 310 is a cylindrical surface having the same central axis as the central conductor 310. Therefore, the conductive member 282 disposed on the substrate 280 is preferably shaped along the cylindrical surface that serves as the equipotential surface. (Refer to the cross-section of the power transmission line shown.) Figure 9 (For simplicity, substrates 280 and 284 are not shown.) The cross-section of the equipotential surface (i.e., the equipotential line) is concentrically circular with the center of the central conductor 310, i.e., point O. Therefore, the cross-sectional shape of the conductive member 282 is preferably an arc with radius r1 centered at point O. Similarly, the conductive member 290 formed on substrate 284 is preferably shaped along the cylindrical surface that serves as the equipotential surface. That is, the cross-section of the conductive member 290 is preferably an arc with radius r2 centered at point O.

[0078] The substrates 280 and 284, which are respectively provided with conductive components 282 and 290, are preferably formed into plates bent along the side of the central conductor 310, for example, using glass epoxy resin. When the receiving portion 130 is formed in this way and disposed on the central conductor 310, as... Figure 8 and Figure 9As shown, as long as the transmitting unit 144 (e.g., a horn antenna) is arranged at the opening 314 on the side of the outer conductor 312, the radiation direction is toward the center of the central conductor 310 (i.e., point O), and electromagnetic waves EW (e.g., microwaves) are radiated toward the receiving unit 130.

[0079] Therefore, when the receiving unit 130 receives electromagnetic waves, it can suppress the influence of the electric field formed by the normal operation (i.e., power supply) of the transmission line that is being detected. Thus, the receiving unit 130 can stably receive electromagnetic waves emitted from the transmitting unit 144.

[0080] Alternatively, conductive components 282 and 290 can be formed as thin plates (or films), and substrates 280 and 284, on which conductive components 282 and 290 are respectively disposed, can be formed using malleable components. For example, when substrates 280 and 284 are formed from shape memory resin (e.g., shape memory polymer), if an equipotential surface formed by electrical equipment or electrical wiring is known, substrates 280 and 284 can be heated and deformed into a shape along the equipotential surface. Thus, conductive components 282 and 290 can be deformed into a shape along the equipotential surface and disposed along the equipotential surface.

[0081] In the second embodiment, a fluorescence reflection filter 210 is used to separate the excitation light from the emitted light of the diamond element 216, but this is not a limitation. An LPF can also be used to separate the excitation light from the emitted light of the diamond element 216. Specifically, it can also be configured to... Figure 7 The optical path for transmitting excitation light shown is replaced with the optical path for transmitting emission light, and an LPF structure is used instead of the fluorescence reflection filter 210.

[0082] The above description focuses on the case where excitation light is incident on one surface of a diamond element including the NV center, and the emitted light from that same surface is measured; however, this is not a limitation. When the diamond element including the NV center has multiple flat surfaces, the surface irradiating the excitation light and the surface measuring the emitted light can be different. A flat surface refers to a plane with a defined or greater area; here, a flat surface of the diamond element including the NV center refers to a plane with an area larger than a circle with a diameter of approximately 200 µm. For example, when the diamond element is formed as a cuboid, excitation light is incident on a first flat surface among two surfaces forming a 90-degree angle, and the emitted light from the second flat surface is focused and detected. Alternatively, a third flat surface parallel to the first flat surface can be used as the surface for focusing the emitted light of the object being detected. The diamond element only needs to have at least two flat surfaces and is not limited to a hexahedron; the shape of the diamond element is arbitrary.

[0083] The above description focuses on the use of diamond elements with NV centers in diamond sensor units, but it is not a limitation. Any diamond element with a color center possessing electron spin can be used. A color center with electron spin is a center that forms a spin triplet state and emits light upon excitation; NV centers are representative examples. In addition, color centers with electron spin are known to exist in silicon-vacancy centers (i.e., Si-V centers), germanium-vacancy centers (i.e., Ge-V centers), and tin-vacancy centers (i.e., Sn-V centers). Therefore, diamond sensor units can be constructed using diamond elements including these, instead of diamond elements with NV centers.

[0084] It should be noted that the wavelengths of the excitation light and emitted light (i.e., fluorescence), as well as the frequency of the electromagnetic waves excited by resonance, vary depending on the level of the color center. NV centers are preferred due to their ease of handling in terms of light wavelength and microwave frequency. In the cases of Si-V centers, Ge-V centers, and Sn-V centers, millimeter waves (e.g., 30 GHz to 300 GHz) or submillimeter waves (e.g., 300 GHz to 3 THz) with frequencies higher than microwaves (e.g., 1 GHz to 30 GHz) are used in the irradiated electromagnetic waves. For example, in Si-V centers, millimeter waves of approximately 48 GHz can be used, while in Sn-V centers, submillimeter waves of approximately 850 GHz can be used.

[0085] In the above, a horn antenna is used in the transmitting unit 144 and the receiving unit 252 (see reference). Figure 4 The situation described is not limited to this. Patch antennas (such as microstrip antennas) can also be used instead of horn antennas. By using patch antennas, millimeter waves and submillimeter waves can be transmitted, enabling sensors using Si-V center, Ge-V center, or Sn-V center, etc.

[0086] The optical waveguide is preferably a coaxial structure with two or more layers, having a core portion through which light passes and portions of a material with a different refractive index formed around the core portion. The core portion may not be tightly filled with the light-transmitting medium. Since space itself can transmit light, the core portion can also be a cavity. The optical waveguide is preferably made of optical fiber with a core diameter of 1µm or more and 80µm or less. This is because using optical fiber makes it easier to guide the laser to the desired location and suppresses divergence at the output end of the fiber.

[0087] The focusing element can be formed from any material that has the function of focusing light. For example, it can be a lens formed from a silicon oxide-based raw material (such as glass, or additives other than silicon oxide), or it can be a material with diffraction properties. The focusing element is preferably a lens that transmits light and utilizes the refraction phenomenon. Spherical lenses, hemispherical lenses, and Fresnel lenses are preferred. In particular, due to the relationship between the refractive index and the shape of a sphere, a lens in which the focal point of parallel light is located on the spherical surface is more preferred. This is because if such a lens is used, the optical focus and optical axis adjustment become very simple, and the amount of light can be utilized to the maximum extent.

[0088] When the sensor unit is placed in a high-voltage environment, the optical waveguide (e.g., optical fiber) that transmits the excitation light and the emitted light from the diamond is preferably arranged through an insulating barrier. This isolates the excitation light generating unit and the light receiving unit from the high voltage, protecting the equipment used in the excitation light generating unit and the light receiving unit.

[0089] The electromagnetic wave irradiation section is not limited to a coil shape; it can also be a straight electrical wiring as described later. In this case, the diamond element only needs to be placed on the surface or end of the transmission path (e.g., a conductive component) of the transmission path for electromagnetic waves (e.g., microwaves or millimeter waves). This allows electromagnetic waves to be irradiated with high precision toward the NV center of the diamond.

[0090] When using the aforementioned diamond sensor unit to detect time changes in the magnetic field, etc., using alternating current, it is preferable that the NV center of the diamond element rapidly recovers from its emitted light state to its original state (i.e., the state before excitation) after being excited. Therefore, it is preferable that the spin coherence time T2 of the diamond element is short. For example, the spin coherence time T2 of the diamond element is preferably less than 50 µsec. It should be noted that, since the detection sensitivity is related to (T2)... -1 / 2 The difference is proportional, therefore the smaller T2 is, the lower the detection sensitivity. Therefore, when detecting rapid changes in the magnetic field, such as pulsed magnetic field changes, it is advisable to sacrifice detection sensitivity and shorten the spin coherence time T2 of the diamond element as much as possible.

[0091] To shorten the spin coherence time, it is preferable that the diamond element includes impurities. Considering that a smaller T2 results in lower detection sensitivity, for example, the total hydrogen concentration in the diamond is preferably greater than 0 ppm and less than 1 ppm. Additionally, the NVH (Noise, Vibration, and Harshness) in the diamond... - The concentrations of CH and CH2 are preferably greater than 0 ppm and less than 1 ppm. Here, the concentration (ppm unit) represents the proportion of the number of atoms.

[0092] It should be noted that, in the first embodiment, the diamond sensor unit 100 may also include a transmitting unit 144. Similarly, in the second embodiment, the diamond sensor unit 200 may also include a transmitting unit 144.

[0093] Example 1

[0094] The effectiveness of this disclosure will be demonstrated below through examples. Figure 10 Show Figure 7 An embodiment of the structure shown. Figure 10 In, with Figure 7 The constituent elements shown are labeled with the corresponding constituent elements. Figure 7 Same reference numerals as shown in the attached figures.

[0095] Step-index multimode fiber is used in the first optical waveguide 212 and the second optical waveguide 230. The core diameter of the first optical waveguide 212 is 50µm, and the numerical aperture (NA) is 0.2. The core diameter of the second optical waveguide 230 is 400µm, and the NA is 0.5. A rectangular diamond of 3mm × 3mm × 0.3mm is used in the diamond element 216. A spherical lens with a diameter of 2mm is used in the focusing element 214 to fix the focusing element 214 in contact with the surface of the diamond element 216 (i.e., a flat surface of 3mm × 3mm). In the optical system for transmitting excitation light, in addition to the focusing element 208 and the fluorescence reflection filter 210, a triangular prism 250 is also configured to form a collimating optical system. Thus, the excitation light is adjusted to be incident on the center of the focusing element 214.

[0096] It was used in the electromagnetic wave irradiation unit 218 Figure 11 The coplanar circuit is shown. A copper foil 272, formed on the surface of a glass epoxy board 270 with a side approximately 2 cm thick, is cut into a "コ" shape, forming an electromagnetic wave irradiation section 218 in the center as the main wiring with a width of 1 mm. A diamond element 216 is fixed to the first end of the electromagnetic wave irradiation section 218 opposite the copper foil 272 using silver paste (i.e., at...). Figure 11 (The area is represented by an ellipse with a dotted line). Therefore, microwaves can be irradiated with good precision towards the NV center of the diamond element 216. The second end of the electromagnetic wave irradiation section 218, where the diamond element 216 is not located, and... Figure 10 Connector 254 is used for connection.

[0097] Microwaves are generated by a microwave generating device located at a long distance, transmitted through the air, and received by a receiving unit 252 (see reference). Figure 10 ) Receiver. A transmitter 144 that emits microwaves toward the receiver 252 is used. Figure 4The horn antenna shown has dimensions of L1=110 (mm), L2=87.9 (mm), and L3=254 (mm), and a gain of 10dB. It is used in the receiver 252. Figure 3 The patch antenna shown has a frequency of 2.873 GHz and a maximum gain of approximately 10 dBi. Substrates 280 and 284 are glass epoxy resin substrates (L = 120 mm, t = 1 mm) arranged at an H = 5.2 mm interval. Microwaves received by receiver 252 are transmitted to connector 254 via a transmission path (i.e., a coaxial cable) and irradiated onto diamond element 216 from electromagnetic wave irradiation unit 218.

[0098] A PIN-AMP (i.e., a photodiode IC with a linear current amplification circuit) is used in the photodetector unit 226. The PIN-AMP photodiode used has a sensitivity wavelength range of 300~1000nm and a maximum sensitivity wavelength of 650nm, amplifying the photocurrent generated by the photodiode by 1300 times and outputting it.

[0099] The focusing element 214, diamond element 216, and electromagnetic wave irradiation part 218 constituting the sensor unit are arranged near the electrical wiring 260. An alternating current (50Hz or 60Hz, 30A) flows through the electrical wiring 260, and the resulting fluctuating magnetic field is used as the detection object. The maximum value of the magnetic field formed in the sensor unit by the alternating current is approximately 0.3µT. The power of the microwave emitted from the horn antenna is set to constant (30dBm (=1W)), and the distance D between the sensor unit and the horn antenna emitting the microwave is varied to perform the measurement. The results are as follows: Figures 12A-12C and Figure 13 As shown. In either case, both the sensor and the receiver are positioned at the same distance D from the horn.

[0100] Figures 12A-12C The signal detected by the PIN-AMP is shown when a 50Hz alternating current (30A) flows through electrical wiring 260. Figures 12A-12C The measurements are for D=2.8 (m), D=4 (m), and D=5 (m), respectively. The vertical axis is 10.0 mV per scale increment, and the horizontal axis is 5 ms per scale increment. Figure 13 The signal detected by the PIN-AMP is shown when a 60Hz AC current (30A) flows through electrical wiring 260, with D=10 (m). The vertical axis represents 10.0mV per scale increment, and the horizontal axis represents 4ms per scale increment.

[0101] Depend on Figures 12A-12C and Figure 13It can be seen that if the distance D of the emitted microwave becomes longer, the detected signal will decrease. However, even if a relatively weak microwave of about 1W is emitted from a position about 10m away from the sensor, the change in the magnetic field formed by the alternating current can be fully detected. Figures 12A-12C The detection signal shown varies at an AC frequency of 50Hz. Figure 13 The detection signal shown varies at an AC frequency of 60Hz. It should be noted that microwaves attenuate with distance, but this can be mitigated by adjusting the emitted microwave power, the gain of the radiating antenna, and the gain of the receiving antenna, taking into account the detection limit (i.e., the lower limit of power) of the optical detector and the emission distance. If the receiving unit is placed in a high-voltage environment of 10kV at a distance D of 5cm, discharge will occur at the corners of the horn antenna and the receiving unit, making measurement impossible. If the distance D is set to 30m, the microwave power cannot reach the required level, making it impossible to measure the signal change corresponding to the change in magnetic force (i.e., the change in the magnetic field formed by the alternating current flowing through the electrical wiring 260). If the distances D are set to 50cm and 1m, the signal strengths are... Figure 12A The signal strength is 5 times and 4 times that of the noise average. Here, signal strength refers to the difference between the maximum and minimum values ​​obtained by averaging the noise. Figure 12A Signal strength refers to, regarding Figure 12A The data is the difference between the maximum and minimum values ​​obtained by averaging the noise. As mentioned above, if the distance D is set to 30m, the microwave power cannot reach the signal, so a smaller distance D is preferred. However, signal strength depends not only on microwave power, so if the distance D is small enough, the signal strength becomes sufficiently high, leading to a saturation tendency. Therefore, as a diamond sensor unit, it is considered good if the distance between the horn antenna (specifically the horn section) and the sensor section (specifically the receiver section) is 50cm or more and 10m or less, allowing for measurement and confirmation.

[0102] In the above, coplanar circuits are formed on a substrate with one side approximately 2cm, but a rectangular substrate with one side approximately 5cm or less can also be used.

[0103] The present disclosure has been described above by way of example, but the above-described embodiments are merely examples and the present disclosure is not limited to the above-described embodiments. The scope of the present disclosure is defined by the claims, based on the detailed description of the invention, and includes all modifications within the meaning and scope equivalent to the statements therein.

[0104] Explanation of reference numerals in the attached figures

[0105] 100, 200 diamond sensor units

[0106] 102, 202 Light-emitting elements

[0107] Concentrating elements: 104, 114, 124, 204, 208, 214, 224

[0108] 106, 206 Excitation Light Generating Section

[0109] 110, 210 Fluorescent Reflection Filters

[0110] 112 Optical waveguide

[0111] 116 and 216 diamond components

[0112] Electromagnetic wave irradiation section 118, 218

[0113] 120, 220 sensor section

[0114] 122, 222, 908 LPF

[0115] 126, 226 Optical Detection Department

[0116] Light-receiving sections 128 and 228

[0117] Receiving Units 130 and 252

[0118] 140 Electromagnetic wave generating unit

[0119] 142 Control Department

[0120] 144 Sending Department

[0121] 212 First Optical Waveguide

[0122] 230 Second Optical Waveguide

[0123] 250 triangular prism

[0124] 254, 288, 304 connectors

[0125] 260 Electrical wiring

[0126] 270 Glass epoxy board

[0127] 272 Copper Foil

[0128] 280, 284, 912, 914, 916 base plate

[0129] 282, 290 Conductive components

[0130] 286 spacers

[0131] 300 Adapter Section

[0132] 302 Speaker section

[0133] 306 central axis

[0134] 310 Center Conductor

[0135] 312 External Conductor

[0136] 314 Opening

[0137] 900 LED

[0138] 902 SPF

[0139] 904 diamond

[0140] 906 lens

[0141] 910 photodiode

[0142] d Thickness

[0143] EW electromagnetic waves

[0144] H interval

[0145] L, L3 length

[0146] L1 width

[0147] L2 height.

Claims

1. A diamond sensor unit, comprising: Diamond has color centers, which have electron spin; An excitation light irradiation section irradiates the diamond with excitation light; The first patch antenna receives electromagnetic waves; The electromagnetic wave irradiation unit is set separately from the first patch antenna. The electromagnetic waves received by the first patch antenna are transmitted through the transmission path and irradiate the diamond. The detection unit detects the emitted light from the color center of the diamond after the diamond is irradiated with the excitation light and the electromagnetic wave. as well as An optical waveguide transmits the excitation light and the emitted light.

2. The diamond sensor unit according to claim 1, wherein, The diamond sensor unit further includes a horn antenna or a second patch antenna for transmitting the electromagnetic waves received by the first patch antenna. The horn antenna transmits microwaves as the electromagnetic wave. The second patch antenna transmits microwaves, millimeter waves, or submillimeter waves as the electromagnetic waves.

3. The diamond sensor unit according to claim 1 or 2, wherein, The first patch antenna includes a plate-shaped conductive component that receives the electromagnetic waves, and is disposed on electrical equipment or electrical wiring that is the object of detection. The first patch antenna is configured such that the conductive component is parallel to the equipotential surface formed by the object being detected.

4. The diamond sensor unit according to claim 3, wherein, The equipotential surface is curved. In the first patch antenna, the conductive component is configured along the curved shape.

Images