Diamond spin sensor system

Abstract

A diamond spin sensor system includes: a sensor section including a diamond having a color center with electron spin; a control power supply unit that generates excitation light to be irradiated to the sensor unit; and a joint part connecting the sensor part and the control power supply part, the joint part transmitting the excitation light to the sensor part and irradiating the diamond, and the joint part transmitting the fluorescence emitted from the diamond to the control power supply part.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a diamond spin sensor system. This application claims priority based on Japanese Application No. 2023-100677 filed on June 20, 2023, and the entire content recited in the above-mentioned Japanese application is incorporated by reference. BACKGROUND

[0002] In a power cable configured at a high place such as a tower as a power transmission and distribution device, in order to perform maintenance management and abnormality detection thereof, a device provided with a temperature detector, a current detector, and the like is provided in the power cable. For example, in the following Patent Literature 1, a structure is disclosed in which, in order to detect a failure site occurring in a power transmission and distribution line or the like, an optical sensor (utilizing Faraday effect or Pockels effect) is configured on the high voltage side, and a detected optical signal is transmitted to a monitoring control system on the ground side through an optical fiber of an optical fiber embedded insulator.

[0003] In addition, in order to eliminate a wire (optical fiber or the like) for connecting a detection device provided in a power cable and a device provided on the ground, the detection device is also provided with a wireless communication function. That is, information such as a temperature and a current value detected by the detection device provided in the power cable is transmitted to the device provided on the ground through a wireless communication unit in the detection device.

[0004] As a sensor for detecting a magnetic field, a temperature, and the like, a diamond spin sensor system using an NV center (that is, an NV color center) of a diamond is known. The NV color center formed by a nitrogen at a substitution site of carbon entering the diamond and a vacancy adjacent to the nitrogen becomes a triplet state (that is, spin S is S=1) when it is negatively charged (this state is denoted as an NV- color center). When the NV color center is excited by a wavelength of 532 nm (that is, green light), fluorescence of a wavelength of 637 nm (that is, red light) is emitted. The emission intensity of the fluorescence changes depending on the spin state, and the spin state changes depending on the magnetic resonance of a microwave or a radio wave applied to the NV color center, and thus it can be used as a magnetic sensor.

[0005] For example, the diamond spin sensor system includes a diamond substrate containing an NV color center, an optical system that transmits excitation light from a light source and irradiates the NV color center, an optical system that condenses fluorescence from the NV color center and transmits it to a light detector, and a waveguide that transmits a microwave from a power source and irradiates the NV color center. For example, in the following Non-Patent Literature 1, a structure is disclosed in which a diamond sensor is loaded on a coplanar waveguide to irradiate a microwave. The shape of the diamond substrate is a rectangular parallelepiped, excitation light is irradiated from the side surface of the diamond substrate, and fluorescence is condensed from the diamond substrate.

[0006] PRIOR ART DOCUMENTS PATENT LITERATURE Patent Literature 1: Japanese Patent Application Laid-Open No. 2003-35852 Non Patent Literature Non Patent Literature 1: Masataka Masuya, Yuji Hatano, Takayuki Iwai, Mutsumi Hatano, "High sensitivity macroscopic diamond magnetometer using coplanar waveguide", Abstracts of the 79th Autumn Meeting of the Applied Physics Society (Issued on September 5, 2018) Non Patent Literature 2: Takamasa Okamoto, Kazuhiro Nakamura, Hiroki Morishita, Masanori Fujihara, Shiro Saito, Kenkichi Mizukami, "Temperature sensor integrated with diamond NV color center", Abstracts of the 78th Autumn Meeting of the Applied Physics Society (Issued on August 25, 2017) SUMMARY

[0007] The diamond spin sensor system according to an aspect of the present disclosure includes a sensor portion including a diamond having a color center with an electron spin, a control power supply portion that generates excitation light to be irradiated to the sensor portion, and a joint portion that connects the sensor portion and the control power supply portion, the joint portion transmitting the excitation light to the sensor portion and irradiating the diamond, and the joint portion transmitting fluorescence emitted from the diamond to the control power supply portion. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a block diagram showing the structure of the diamond spin sensor system according to the first embodiment.

[0009] Figure 2 is a block diagram showing the structure of the diamond spin sensor system according to the first embodiment. Figure 1 is a cross-sectional view showing the structure of the joint portion shown in

[0010] Figure 3 is a cross-sectional view showing the structure of the joint portion shown in Figure 1 is a schematic view showing an example of arrangement of the diamond spin sensor system shown in

[0011] Figure 4 is a schematic view showing the structure of the joint portion according to the first modification.

[0012] Figure 5 is a schematic view showing the structure of the joint portion according to the second modification.

[0013] Figure 6 is a cross-sectional view showing the structure of the joint portion according to the third modification.

[0014] Figure 7 is a schematic view showing the structure of the joint portion according to the fourth modification.

[0015] Figure 8 is a block diagram showing the structure of the diamond spin sensor system according to the second embodiment.

[0016] Figure 9 It means Figure 8 The diagram shows a cross-sectional view of the structure of the microwave connector.

[0017] Figure 10 This is a schematic diagram showing the structure of the diamond spin sensor system involved in the first embodiment.

[0018] Figure 11 It is represented in tabular form based on Figure 10 The diagram shows the measurement results of the structure.

[0019] Figure 12 This is a schematic diagram showing the structure of the measurement system involved in the first comparative example.

[0020] Figure 13 It is represented in tabular form based on Figure 12 The diagram shows the measurement results of the structure.

[0021] Figure 14 This is a schematic diagram illustrating the structure of the diamond spin sensor system involved in the second embodiment.

[0022] Figure 15 It is represented in tabular form based on Figure 14 The diagram shows the measurement results of the structure.

[0023] Figure 16 This is a schematic diagram illustrating the structure of the diamond spin sensor system involved in the third embodiment.

[0024] Figure 17 It is represented in tabular form based on Figure 16 The diagram shows the measurement results of the structure.

[0025] Figure 18 This is a schematic diagram showing the structure of the diamond spin sensor system involved in the fourth embodiment.

[0026] Figure 19 It is represented in tabular form based on Figure 18 The diagram shows the measurement results of the structure. Detailed Implementation

[0027] [The problem this disclosure aims to solve] Existing systems for maintaining and managing power cables include: mechanisms that supply power to detection equipment via wires other than the power cables; mechanisms that detect temperature and current at different locations; and mechanisms that transmit the detected information to ground-based equipment via wired or wireless means. Therefore, multiple and varied electronic components are used, including those that convert power into control data, those that convert temperature and current into digital information, and those that transmit the information to the ground. Furthermore, to operate in environments with large temperature fluctuations, such as temperature cycling, the airtightness of the equipment needs to be improved, leading to problems such as heat retention inside the equipment, shortened lifespan of electronic components, and increased susceptibility to failure. When an electronic component fails, the power supply to the power cable must be stopped and repairs performed. This applies not only to wires and cables but also to high-voltage equipment. Additionally, in existing systems using multiple and varied electronic components, maintaining maintenance before component failure requires setting maintenance intervals based on the lifespan of each component, which presents a complex problem.

[0028] Furthermore, the same problem exists not only in high-voltage environments such as power transmission and distribution equipment, but also in harsh environments such as real-time sensing of physical states (voltage, current, and temperature) in high-voltage, high-temperature, extremely low-temperature, strong acid, and strong alkali environments.

[0029] Therefore, the purpose of this disclosure is to provide a diamond spin sensor system that can detect physical states in harsh environments, has a long product life, and is easy to maintain.

[0030] [The Effects of This Disclosure] According to this disclosure, a diamond spin sensor system that can detect physical states in harsh environments, has a long product life, and is easy to maintain can be provided.

[0031] [Description of embodiments of this disclosure] The embodiments described herein are presented in an explanatory manner. At least some of the embodiments described below may be combined arbitrarily.

[0032] (1) The diamond spin sensor system according to the first aspect of this disclosure includes: a sensor section containing a diamond having a color center with electron spin; a control power supply section generating excitation light that irradiates the sensor section; and a connector section connecting the sensor section and the control power supply section, wherein the connector section transmits the excitation light to the sensor section and irradiates the diamond, and the connector section transmits fluorescence emitted from the diamond to the control power supply section. Therefore, since the sensor section contains a diamond that can withstand harsh environments as a sensor element, a diamond spin sensor system capable of detecting physical states (voltage, current, temperature, etc.) in harsh environments, with long product life and easy maintenance, is realized.

[0033] (2) Based on (1) above, the sensor unit can be configured in a first environment, and the control power supply unit can be configured in a second environment different from the first environment. The first environment can be at least one order of magnitude larger than the second environment in terms of voltage and temperature. Thus, the control power supply unit can be configured in a normal environment, and a diamond spin sensor system with long product life and easy maintenance can be realized.

[0034] (3) Based on (1) or (2) above, the sensor unit may further include an optical waveguide that transmits excitation light to the diamond. The optical waveguide may be formed of a transparent resin, a transparent nitride, or a transparent oxide. The diamond and the connection between the diamond and the optical waveguide may be isolated from the outside air. Thus, the sensor unit can be placed in a more severe environment.

[0035] (4) Based on (3) above, the joint may include an insulator, and the insulator may have a structure inside the insulator that allows the excitation light to pass through. Thus, the excitation light can be transmitted efficiently, and the mechanism disposed inside the joint can be prevented from being damaged.

[0036] (5) Based on (4) above, an uncovered light transmission component that allows the excitation light to pass through can be arranged inside the connector, or a space that allows the excitation light to pass through can be formed inside the connector. This reduces manufacturing time and manufacturing costs.

[0037] (6) Based on (5) above, a space is formed inside the connector, and a lens that allows excitation light to pass through can be provided inside the connector. As a result, the transmission efficiency of excitation light based on the space inside the connector can be improved.

[0038] (7) Based on (6) above, the diamond spin sensor system can have multiple optical fibers that transmit fluorescence emitted from the diamond and direct it to the lens. These multiple optical fibers can be bundled together. This improves the collection efficiency of the fluorescence emitted from the diamond.

[0039] (8) Based on (1) or (2) above, the joint may include an insulator, and the insulator may have a structure inside the insulator that allows the excitation light to pass through. Thus, the excitation light can be transmitted efficiently, and the mechanism disposed inside the joint can be prevented from being damaged.

[0040] (9) Based on (1) to (3) and (8) above, an uncovered light transmission component that allows the excitation light to pass through can be arranged inside the connector. As a result, manufacturing time can be reduced and manufacturing costs can be lowered.

[0041] (10) Based on (1) to (3) and (8) above, the interior of the connector can have a space for the excitation light to pass through. As a result, manufacturing time can be reduced and manufacturing costs can be lowered.

[0042] (11) Based on any one of (1) to (10) above, the diamond spin sensor system may further include: an electromagnetic wave generating unit that outputs microwaves; and a microwave connector unit, wherein the sensor unit includes a microwave circuit or a microwave waveguide, and the microwave connector unit includes: a transmitting unit that radiates microwaves input from the electromagnetic wave generating unit; and a receiving unit that receives microwaves radiated from the transmitting unit, and can output microwaves received by the receiving unit to the microwave circuit or microwave waveguide included in the sensor unit, wherein a space for the propagation of microwaves radiated by the transmitting unit may be formed in the microwave connector unit. Thus, the magnetic field can be calculated based on the interval between two troughs in the observed spectrum.

[0043] (12) Based on (11) above, the transmitting unit may include a first concave surface that radiates microwaves, and the receiving unit may include a second concave surface that focuses microwaves. The shapes of the first and second concave surfaces may each be part of a parabola or a sphere. This improves the transmission efficiency of microwaves based on the space within the microwave connector.

[0044] [Details of the embodiments disclosed herein] 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.

[0045] (First Implementation) Reference Figure 1 The diamond spin sensor system 100 according to the first embodiment of this disclosure includes a sensor unit 102, a connector unit 104, a control power supply unit 106, and an optical waveguide 108. The sensor unit 102 includes a diamond 110 having an NV color center (hereinafter referred to as an NV color center) and an optical waveguide 112. The optical waveguide 112 includes a light-transmitting medium, which is coated with resin or the like. The optical waveguide 112 is, for example, an optical fiber. The sensor unit 102 (specifically, the optical waveguide 112) is connected to the connector unit 104 via a connector 140. As described later, the connector unit 104 includes a light-transmitting medium and is connected to the optical waveguide 108 via a connector 142. The optical waveguide 108 includes a light-transmitting medium. The optical waveguide 108 is, for example, an optical fiber. The optical waveguide 112, the connector unit 104, and the optical waveguide 108 all transmit light bidirectionally.

[0046] Reference Figure 2The connector 104 includes a first receiving portion 200, a second receiving portion 202, and a third receiving portion 204. The first receiving portion 200 is, for example, an insulator, formed of ceramic or resin. The connector 104 also includes a light transmission member 206, a hammer-shaped member 208, and a hammer-shaped member 210 housed inside the first receiving portion 200 (i.e., the space surrounded by a cylindrical inner wall). The light transmission member 206 is, for example, a rod-shaped quartz. The sides of the light transmission member 206 may or may not be covered. The hammer-shaped member 208 is disposed at a first end of the light transmission member 206, and the hammer-shaped member 210 is disposed at a second end of the light transmission member 206.

[0047] The second housing 202 and the third housing 204 are, for example, formed of resin. The connector 104 further includes an optical fiber 212 housed inside the second housing 202 and an optical connector 216 disposed on the wall of the second housing 202. A first end of the optical fiber 212 is connected to a hammer-shaped member 208, and a second end of the optical fiber 212 is connected to the optical connector 216. The optical connector 216 connects to the optical waveguide 108 (see reference 108). Figure 1 ) connection. Optical connector 216 corresponds to Figure 1 The connecting portion 142 is shown. Additionally, the connector portion 104 also includes an optical fiber 214 housed in the third housing portion 204 and an optical connector 218 disposed on the wall of the third housing portion 204. The first end of the optical fiber 214 is connected to the hammer-shaped member 210, and the second end of the optical fiber 214 is connected to the optical connector 218. The optical connector 218 connects to the optical waveguide 112 (see reference 112). Figure 1 ) connection. Optical connector 218 corresponds to Figure 1 The connecting part 140 shown.

[0048] Furthermore, as a measure to combat moisture inside the first housing 200, the second housing 202, and the third housing 204, it is preferable that the joints between the first housing 200 and the second housing 202, and between the first housing 200 and the third housing 204, be in close contact with a sealing member such as resin. Similarly, it is preferable that the joints between the second housing 202 and the optical connector 216, and between the third housing 204 and the optical connector 218, be in close contact with a sealing member.

[0049] Hammer-shaped member 208 is a member for connecting optical fiber 212 and optical transmission member 206. That is, as described later, hammer-shaped member 208 directs excitation light, which is input from optical connector 216 to optical fiber 212, transmitted through optical fiber 212, and emitted from a first end of optical fiber 212, to the first end of optical transmission member 206. Hammer-shaped member 210 is a member for connecting optical transmission member 206 and optical fiber 214. That is, hammer-shaped member 210 focuses excitation light propagating in optical transmission member 206 and output from a second end of optical transmission member 206, directing it to the first end of optical fiber 214. Hammer-shaped members 208 and 210 are formed, for example, of glass (quartz glass, etc.).

[0050] return Figure 1 The control power supply unit 106 irradiates the diamond 110 with excitation light and detects the fluorescence emitted from the diamond 110. The control power supply unit 106 includes an excitation light generating unit 120, a filter 122, a focusing element 124, an LPF 126, a photodetector unit 128, and a control unit 130. The control unit 130 includes a CPU (Central Processing Unit), a storage unit, and a wireless communication unit (none shown). The processing performed by the control unit 130, described later, is implemented by the CPU reading and executing a program pre-stored in the storage unit. As described later, the control unit 130 acquires the signal (i.e., fluorescence intensity) detected by the photodetector unit 128 and transmits it to an external device via the wireless communication unit. The external device calculates physical states (e.g., magnetic field and temperature) based on the detection signal received from the control unit 130 by the photodetector unit 128.

[0051] The excitation light generating unit 120 is controlled by the control unit 130 to generate excitation light for exciting the NV color centers of the diamond 110. The control unit 130 supplies a voltage to the excitation light generating unit 120 at predetermined timings to cause it to emit light. The excitation light is green light (i.e., wavelength 490 nm to 560 nm). The excitation light is preferably a laser, and the excitation light generating unit 120 is preferably a semiconductor laser (e.g., emitting light with a wavelength of 532 nm).

[0052] Filter 122 is an element used to separate the excitation light incident from the excitation light generation unit 120 and the light emitted from the diamond (i.e., fluorescence). For example, filter 122 is a filter that blocks (i.e. reflects) light with wavelengths below a predetermined wavelength and allows light with wavelengths larger than the predetermined wavelength to pass through, or a bandpass filter that allows light with wavelengths within a predetermined wavelength range to pass through and blocks (i.e. reflects) light with wavelengths outside the predetermined wavelength range. Generally, since the wavelength of the excitation light is shorter than that of the fluorescence, such a structure is preferred. Filter 122 is preferably a dichroic mirror having such a function.

[0053] The focusing element 124 focuses the excitation light input from the filter 122. The focusing element 124 is, for example, a spherical lens. The focusing element 124 inputs as much of the excitation light diffused from the excitation light generating section 120 as possible into the end of the optical waveguide 108. The optical waveguide 108 has a first end and a second end, and transmits the excitation light incident from the focusing element 124 to the first end to the second end. In addition, the optical waveguide 108 transmits the emitted light (i.e., fluorescence) from the diamond incident to the second end to the first end and outputs it.

[0054] LPF126 is a long-pass filter that allows light with wavelengths above a predetermined wavelength to pass through while blocking (e.g., reflecting) light with wavelengths smaller than the predetermined wavelength. Diamond emits red light, which can pass through LPF126, but the excitation light output from excitation light generation unit 120 has a shorter wavelength and therefore cannot pass through LPF126. This suppresses the problem of the excitation light emitted from excitation light generation unit 120 being detected as noise by photodetector unit 128, thus reducing the detection sensitivity of diamond's emitted light (i.e., fluorescence). Photodetector unit 128 generates and outputs an electrical signal corresponding to the incident light. Photodetector unit 128 is, for example, a photodiode. The output signal of photodetector unit 128 is acquired by control unit 130. As described above, the signal acquired by control unit 130 is transmitted to an external device via the wireless communication unit of control unit 130. Thus, the external device can calculate the physical state (e.g., magnetic field and temperature) of the location where diamond 110 is disposed based on the received output signal of photodetector unit 128.

[0055] Reference Figure 3 A diamond spin sensor system 100 is configured in power transmission equipment (e.g., overhead power transmission equipment) for the maintenance and management of power cables and anomaly detection. Specifically, the sensor unit 102 (diamond 110 and optical waveguide 112) is configured on the power transmission line 900, and the control power supply unit 106 is configured on the iron column of the tower 902. A connector 104 is configured, for example, inside an insulator 904. An optical waveguide 108 connecting the connector 104 and the control power supply unit 106 is fixed to the arm of the tower 902, etc.

[0056] Using NV color centers, the magnetic field can be calculated based on changes in the ESR (Electron Spin Resonance) spectrum. Furthermore, the resonance frequency of NV color centers is known to be temperature-dependent in the range of 120K to 700K. For example, as disclosed in Non-Patent Document 2, temperature can be measured based on changes in the ODMR (Optically Detected Magnetic Resonance) signal intensity near the resonance frequency.

[0057] This device can detect the magnetic field generated by the current flowing through the transmission line 900 or the fluorescence corresponding to the temperature of the transmission line 900 using the diamond 110 of the sensor unit 102. The detection signal is transmitted to the control power supply unit 106 via the connector unit 104 and the optical waveguide 108, and then sent to the ground via the control power supply unit 106. Thus, it is possible to detect the magnetic field or temperature at the location where the diamond 110 is placed. In the vicinity of the high-voltage transmission line 900 (e.g., 6600kV or higher), i.e., in a harsh high-voltage environment, only the sensor unit 102 is placed, while the optical waveguide 108 and the control power supply unit 106 are placed in a normal environment away from the transmission line 900. The diamond 110 constituting the sensor unit 102 and the optical waveguide 112 are unaffected by the environment even when placed in a high-voltage environment. The optical waveguide 108 and the control power supply unit 106 are placed in a normal environment. Therefore, a diamond spin sensor system with long product life and easy maintenance can be realized.

[0058] Through such Figure 2 The connector 104 is configured as shown, and can be configured to accommodate two different environments. For example, the third housing 204 can be configured in a harsh environment, while the second housing 202 can be configured in a normal environment. Figure 3 In this configuration, the connector 104 is positioned between a high-voltage environment and a normal environment. The components constituting the connector 104 are made of materials resistant to high voltage. This allows the control power supply 106 and the optical waveguide 108 to be positioned in a normal environment, enabling a diamond spin sensor system with a long product lifespan and easy maintenance. Furthermore, "harsh environment" refers to environments difficult for humans to access, such as... Figure 3 In this context, "normal environment" refers to the high-voltage environment surrounding the power transmission line 900. "Normal environment" refers to an environment other than "harsh environment." In a harsh environment, at least one of the following is greater than in a normal environment (e.g., by an order of magnitude): electric field strength, magnetic field strength, temperature, and pressure.

[0059] Optical waveguides 112 and 108 can also be formed of transparent resin, transparent nitride, or transparent oxide. Diamond 110 is preferably covered with resin or ceramic to isolate it from external air. Furthermore, the connection between diamond 110 and optical waveguide 112 is also preferably sealed with resin or ceramic to isolate it from external air. This allows the sensor unit 102 to be placed in harsher environments.

[0060] As described above, an insulator can be used in the first receiving portion 200 of the connector portion 104, and a structure for transmitting excitation light (i.e., light transmission member 206) can be provided in the first receiving portion 200 (i.e., the insulator). As a result, the excitation light can be transmitted efficiently, and the mechanism disposed inside the connector portion 104 can be prevented from being damaged by harsh environments such as high voltage.

[0061] As described above, the covering of the side of the optical transmission member 206 is arbitrary, but without covering the side of the optical transmission member 206, manufacturing time and manufacturing costs can be reduced.

[0062] (First variation) In the above-described case, the docking head 104 includes a rod-shaped optical transmission component 206, an optical fiber 212, and an optical fiber 214 (see reference). Figure 2 This has been explained, but it is not limited to this. (See also...) Figure 4 The connector portion 104 may also include an optical fiber 230 instead of the optical transmission components 206, 212, and 214. The optical fiber 230 is spiral-shaped and disposed inside the first receiving portion 200. A covering portion 232 and a covering portion 234 are disposed at both ends of the optical fiber 230, while the remaining portion of the optical fiber 230 is not covered. The covering portions 232 and 234 are formed, for example, by a resin coating. The two ends of the optical fiber 230 with the covering portions 232 and 234 are connected to the optical connectors 216 and 218 (see reference). Figure 2 )connect.

[0063] The optical fiber 230 is fixed to the inner wall 240 of the first receiving portion 200 by a plurality of support members 236. The support members 236 are formed of fluororesin such as Teflon (registered trademark). This prevents the uncoated parts of the optical fiber 230 from contacting each other. Therefore, light (i.e., excitation light) input from the optical connector 216 to the optical fiber 230 can be stably transmitted to the optical connector 218, and light (i.e., fluorescence) input from the optical connector 218 to the optical fiber 230 can be stably transmitted to the optical connector 216.

[0064] (Second variation) like Figure 2 As shown, when the optical transmission member 206 is disposed inside the first receiving portion 200, it is preferable to provide a mechanism for holding the optical transmission member 206. For example, see reference... Figure 5The optical transmission member 206 is held inside the first receiving portion 200 by a plurality of support members 250. The support members 250, for example, are made of Teflon and are formed in a ring shape (donut shape) around the optical transmission member 206, with the outer periphery of the support members 250 contacting the inner wall 240 of the first receiving portion 200. This allows the optical transmission member 206 to be stably disposed inside the first receiving portion 200, and even in an environment where the connector portion 104 is disposed (e.g., a power cable) and subjected to mechanical vibration, the internal structure of the connector portion 104 can be maintained, preventing damage to the interior of the connector portion 104.

[0065] (Third variation) In the above, regarding the joint portion 104 (refer to...) Figure 2 The internal configuration of the light transmission component 206 has been described, but it is not limited to this. The light propagation function inherent in space itself can also be utilized. (See reference...) Figure 6 The connector 114 involved in the third modification includes a first receiving portion 200, a second receiving portion 202, and a third receiving portion 204, optical fiber 212, optical fiber 214, optical connector 216, and optical connector 218. The connector 114 is located within the connector 104 (refer to...). Figure 2 The light transmission member 206 is removed, and the hammer-shaped member 208 and hammer-shaped member 210 are replaced by lenses 300 and 302. A space 220 is formed, surrounded by the cylindrical inner wall of the first receiving portion 200. Figure 6 In the middle, it is marked with Figure 2 Elements with the same reference numerals have the same Figure 2 The same function. Therefore, there is no need to repeat the explanation.

[0066] Both lenses 300 and 302 are convex lenses. In the connector 114, the first end of the optical fiber 212 is positioned at the focal point F of lens 300, and the first end of the optical fiber 214 is positioned at the focal point F of lens 302. Thus, the light input to the optical connector 216 and emitted from the first end of the optical fiber 212, i.e., the excitation light 304, is incident on lens 300 and output as parallel light. The excitation light 304, output as parallel light from lens 300, converges from lens 302 towards its focal point F after incident on lens 302, and is then incident on the first end of the optical fiber 214.

[0067] Furthermore, the light, i.e., fluorescence, emitted from the first end of the optical fiber 214 and input to the optical connector 218, is output as parallel light from the lens 302 after being incident on the lens 302. The fluorescence, output as parallel light from the lens 302, is then incident on the lens 300, output from the lens 300, focused towards the focal point F of the lens 300, and incident on the first end of the optical fiber 212. Subsequently, the fluorescence 306 propagates in the optical fiber 212 and is output from the optical connector 216.

[0068] Through such Figure 6 The connector 114 is configured as shown, and the connector 114 can connect with the connector 104 (see reference). Figure 2 Similarly, it can be configured across two different environments. For example, the third housing 204 can be configured in a harsh environment, while the second housing 202 can be configured in a normal environment. Thus, the control power supply 106 and the optical waveguide 108 can be configured in a normal environment, enabling a diamond spin sensor system with long product life and easy maintenance.

[0069] As described above, a space 220 is formed inside the connector portion 114 to allow the excitation light 304 to pass through. Therefore, with... Figure 2 Compared to the connector 104 shown, it can reduce manufacturing time and manufacturing costs.

[0070] As described above, lenses 300 and 302, which allow the excitation light 304 to pass through, are arranged inside the connector portion 114. This improves the transmission efficiency of the excitation light 304 within the space 220 inside the connector portion 114.

[0071] (Fourth variation) In the above, regarding the joint portion 114 (refer to...) Figure 6 The description focuses on the case where the second housing section 202 and the third housing section 204 are each equipped with one optical fiber 212 and one optical fiber 214, respectively, but this is not a limitation. Multiple optical fibers may also be configured in the second housing section 202 and the third housing section 204. Figure 7 As shown, at the connector 114 (refer to...) Figure 6 In this configuration, multiple optical fibers 310 and 312 can be used to replace optical fibers 212 and 214 respectively, and optical connectors 314 and 316 can be used to replace optical connectors 216 and 218 respectively. Multi-core fiber optic cables 318 and 320 can replace optical waveguides 108 and 112 respectively (see reference). Figure 1 In addition, in Figure 7 The first containment section 200, the second containment section 202, and the third containment section 204 are not shown in the figure.

[0072] Multiple optical fibers 310 are connected to optical connector 314, and multiple optical fibers 312 are connected to optical connector 316. The multiple optical fibers included in the multiple optical fibers 310 are connected one-to-one with the optical fibers included in the multi-core optical fiber cable 318 via optical connector 314. The multiple optical fibers included in the multiple optical fibers 312 are connected one-to-one with the optical fibers included in the multi-core optical fiber cable 320 via optical connector 316. The multiple optical fibers 310 and multiple optical fibers 312 are bundled together. The first end of one of the multiple optical fibers 310 (hereinafter referred to as the first excitation light fiber) is connected to optical fiber 212 (refer to...) Figure 6 Similarly, it is positioned at the focal point of lens 300. The first end of one of the multiple optical fibers 312 (hereinafter referred to as the second excitation fiber) is connected to optical fiber 214 (refer to...). Figure 6 Similarly, it is positioned at the focal point of lens 302.

[0073] Excitation light 304 is input into one optical fiber (the optical fiber coupled to the optical fiber used for the first excitation light) in the multi-core optical fiber cable 318. Thus, it connects with connector 114 (see reference). Figure 6 Similarly, the excitation light 304 propagates in the first excitation fiber of the multiple optical fibers 310, radiates from the first end of the first excitation fiber, and after being incident on the lens 300, is output as parallel light from the lens 300. The excitation light 304, which is output as parallel light from the lens 300, is incident on the lens 302, output from the lens 302, focused towards the focal point F of the lens 302, and incident on the first end of the second excitation fiber of the multiple optical fibers 312. Then, after propagating in one of the optical fibers in the multi-core optical fiber cable 320 that is coupled to the second excitation fiber, the excitation light 304 irradiates the diamond 110.

[0074] The fluorescence emitted from the diamond 110 is input into multiple optical fibers of the multi-core fiber optic cable 320, excluding one fiber (the fiber coupled to the second excitation fiber). Thus, the fluorescence 306 propagates in the fibers 312 excluding the second excitation fiber, emitting from the first end of each fiber (near the focal point of lens 302), and after incident on lens 302, is output as approximately parallel light. The fluorescence output as approximately parallel light from lens 302 is then incident on lens 300, output from lens 300, focused near the focal point of lens 300, and incident on the first end of the fibers 310 excluding the first excitation fiber. Then, the fluorescence 306 propagates in the multiple optical fibers of the multi-core fiber optic cable 318 that are not coupled to the first excitation fiber. Therefore, more fluorescence emitted from the diamond 110 can be incident on the fibers of the multi-core fiber optic cable 320, enabling efficient transmission to the multi-core fiber optic cable 318.

[0075] As described above, multiple optical fibers 312 are provided to transmit the fluorescence emitted from the diamond 110 and incident on the lens 302, and these multiple optical fibers are bundled together. This improves the collection efficiency of the fluorescence emitted from the diamond 110.

[0076] (Second Implementation) In the first embodiment, a diamond spin sensor system that does not use microwaves was described. In contrast, the diamond spin sensor system according to the second embodiment uses microwaves.

[0077] The diamond spin sensor system 150 according to the second embodiment of this disclosure includes a sensor unit 102, a connector unit 104, a control power supply unit 106, an optical waveguide 108, an electromagnetic wave generator unit 152, a microwave connector unit 154, a microwave transmission path 156, a microwave transmission path 158, and a microwave circuit 160. The diamond spin sensor system 150 is... Figure 1 The diamond spin sensor system 100 shown includes an electromagnetic wave generator 152, a microwave connector 154, a microwave transmission path 156, a microwave transmission path 158, and a microwave circuit 160. Figure 8 In the middle, it is marked with Figure 1 Elements with the same reference numerals have the same Figure 1 The same functions are described again. Therefore, they will not be repeated. In addition to the functions described above, the control unit 130 also has the function of controlling the electromagnetic wave generating unit 152. That is, the program for controlling the electromagnetic wave generating unit 152 is stored in the storage unit included in the control unit 130 and executed by the CPU included in the control unit 130.

[0078] The electromagnetic wave generating unit 152, controlled by the control unit 130, generates electromagnetic waves (e.g., microwaves). The generated electromagnetic waves are transmitted through the microwave transmission path 156 and input to the microwave connector 154. The microwave transmission path 156 is, for example, a coaxial cable. The microwave connector 154 allows the input electromagnetic waves to propagate within itself and then input to the microwave transmission path 158. The microwave transmission path 158 transmits the input electromagnetic waves to the microwave circuit 160, which then irradiates the diamond 110. The microwave transmission path 158 is, for example, a coaxial cable. The microwave circuit 160 is, for example, a coil containing an electrical conductor. The microwave circuit 160 can be a coplanar circuit or a microstrip circuit, etc.

[0079] The control unit 130 controls the excitation light generating unit 120 to output excitation light 304 for a predetermined time (e.g., period t1) at a predetermined time. The control unit 130 controls the electromagnetic wave generating unit 152 to output electromagnetic waves at a predetermined time (e.g., period t2). An appropriate pulse sequence can be used for the pulse sequence in period t2. Thus, the electromagnetic waves and the excitation light are combined temporally and spatially to irradiate the diamond 110. The control unit 130 receives the output signal of the photodetector 128 at a predetermined time (e.g., period t3) and stores it in the storage unit.

[0080] For example, diamond 110 (i.e., the NV center) is excited by irradiating it with 2.87 GHz microwaves and then with green light. As a result, the transitions in which the spin of the NV center returns to the ground state include non-emissive (i.e., fluorescent) transitions, thus reducing the intensity of the observed emitted light. Consequently, two troughs (i.e., signal notches) are observed in the ESR spectrum. The interval Δf (i.e., the frequency difference) between the two observed troughs depends on the magnetic field strength at the location of diamond 110. The control unit 130 transmits the output signal of the photodetector 128 to an external device via the wireless communication unit, thereby enabling the external device to calculate Δf and, based on Δf, calculate the magnetic field.

[0081] Reference Figure 9 The microwave connector 154 includes a first receiving portion 400, a second receiving portion 402, and a third receiving portion 404. The first receiving portion 400 is, for example, an insulator, formed of ceramic or resin. A space 406 surrounded by a cylindrical inner wall is formed inside the first receiving portion 400.

[0082] The second receiving portion 402 and the third receiving portion 404 are, for example, formed of resin. The microwave connector portion 154 further includes a transmitting portion 410 housed inside the second receiving portion 402, a receiving portion 412 housed in the third receiving portion 404, a high-frequency cutoff filter 414, and a microwave transmission path 416. The transmitting portion 410 and the receiving portion 412 are, for example, antennas, having concave surfaces (e.g., parabolic surfaces, such as paraboloids or elliptic paraboloids) formed by components that reflect electromagnetic waves. The transmitting portion 410 and the receiving portion 412 are arranged opposite each other with their respective openings. Furthermore, the concave surfaces of the transmitting portion 410 and the receiving portion 412 may also be part of a sphere. In this case, if the solid angle of the concave surface is small, electromagnetic waves incident parallel to the central axis of the concave surface can be focused to a single point (i.e., a focal point).

[0083] The end of the microwave transmission path 156 is positioned at the focal point of the transmitting unit 410. Electromagnetic waves propagating in the microwave transmission path 156 and emitted from its end are reflected by the transmitting unit 410 and emitted parallel to it. The end of the microwave transmission path 416 is positioned at the focal point of the receiving unit 412. Electromagnetic waves emitted parallel to it by the transmitting unit 410 are reflected by the receiving unit 412 and focused at its focal point, and received by the end of the microwave transmission path 416. The electromagnetic waves received by the microwave transmission path 416 are output to the high-frequency cutoff filter 414. The high-frequency cutoff filter 414 removes high frequencies above a predetermined frequency from the input electromagnetic waves and outputs them to the microwave transmission path 158. Thus, as described above, the electromagnetic waves output from the electromagnetic wave generating unit 152 are transmitted to the microwave circuit 160 via the microwave transmission path 156, the microwave connector 154, and the microwave transmission path 158, and irradiate the diamond 110 through the microwave circuit 160.

[0084] Therefore, as mentioned above, the magnetic field can be calculated based on the interval Δf between the two troughs in the observed spectrum.

[0085] As described above, the transmitting unit 410 includes a first concave surface that radiates microwaves, and the receiving unit 412 includes a second concave surface that converges microwaves. The shapes of the first and second concave surfaces are each part of a parabola or a sphere. This improves the microwave transmission efficiency within the space 406 of the microwave connector 154.

[0086] Furthermore, when the electromagnetic wave is a microwave and its wavelength is too long, microwaves can be loaded onto millimeter waves, that is, the millimeter wave is used as a carrier wave and modulated and transmitted through microwaves. When irradiating diamond with microwaves, if microwaves with a wavelength of about 10 cm are used directly, the wavelength is too long, thus causing problems with direct penetration and focusing. If millimeter waves are used, the wavelength is only a few millimeters, so the direct penetration and focusing are superior to microwaves. Therefore, millimeter waves are first used as carrier waves for propagation, focusing and collecting energy, and then the energy is extracted as microwaves through wave division and used to irradiate the diamond. This enables a system with improved energy efficiency.

[0087] The above description illustrates the case where microwaves are transmitted to the microwave circuit 160 via microwave transmission path 158 and irradiate the diamond 110, but this is not a limitation. Microwaves output from the microwave connector 154 can also be transmitted to the diamond 110 via a microwave waveguide for irradiation. A microwave waveguide is a circuit with a cylindrical or square-shaped cavity in which microwaves propagate. A microwave waveguide can be a coaxial cable through which microwaves can pass, or it can be a cylindrical (cavity) with a square cross-section. Regarding square cylindrical microwave waveguides, microwave waveguides with dimensions suitable for the wavelength of microwaves are used.

[0088] The experimental results are shown below. As described above, a diamond spin sensor system including a connector was used to measure the magnetic field formed by the current flowing through the wire.

[0089] (First embodiment) Reference Figure 10 The diamond spin sensor system according to the first embodiment includes a diamond 500, an optical waveguide 502, an optical waveguide 504, an optical waveguide 510, a measuring unit 520, and a power supply unit 522. The optical waveguides 502, 504, and 510 are connected by an optical connector 506 and an optical connector 508.

[0090] Diamond 500 is manufactured as follows: It is synthesized using a high-temperature, high-pressure method, producing diamond containing 30 ppm of substituted nitrogen, shaped into a 2mm x 2mm square with a thickness of 2mm. (The last sentence appears to be incomplete and possibly refers to a specific process or method.) 18 cm -2 The resulting diamond was irradiated with an electron beam of 3 MeV energy and then annealed at 950°C for 1 hour. NV- color centers were formed in the resulting diamond, and the magnetism and temperature could be detected by their spins using ODMR (optical detection magnetic resonance) spectroscopy.

[0091] Optical waveguide 502 is connected to the first end of optical waveguide 504 via optical connector 506, and optical waveguide 510 is connected to the second end of optical waveguide 504 via optical connector 508. Optical waveguide 504 is arranged in a spiral shape inside insulator 906, which has a length of approximately 2m, an inner diameter of approximately 0.2m, and a hole length of approximately 0.6m (see the reference for the connector section). Figure 4 Optical waveguides 502 and 510 use either a 0.8 mm diameter linear optical waveguide made of quartz glass (unclad) or a 200 μm core optical fiber (unclad). Optical waveguide 504 also uses either a 0.8 mm diameter linear optical waveguide made of quartz glass or a 200 μm core optical fiber; however, as described later, the difference in insulation durability was evaluated by using both clad and unclad optical fibers.

[0092] A diamond 500 is mounted to the front end of an optical waveguide 502 using a common transparent adhesive. The fluorescence intensity from the diamond 500 can be stably measured using this adhesive. A heat-shrink tube 530 is used to wrap the diamond 500 and a portion of the optical waveguide 502 together. The heat-shrink tube 530 is heated to shrink it, isolating the diamond 500 from the outside air. If the heat-shrink tube 530 is not used to wrap the diamond 500, water droplets may adhere to or scratch it, potentially affecting the detection of magnetic properties. Wrapping the diamond 500 with the heat-shrink tube 530 prevents such problems.

[0093] A conductor 614 is disposed on the first plate 610 and the insulating layer 612, and then a diamond 500 covered by a heat-shrinkable tube 530 is disposed thereon. Hereinafter, the environment in which the diamond 500 is disposed will be referred to as the first environment. The first plate 610 is formed of a conductive metal. The conductor 614 connects a DC power supply 622 to a variable resistor 620 with one end grounded. The DC power supply 622 is capable of outputting a maximum of 20kV.

[0094] The measuring unit 520 generates excitation light (laser) that irradiates the diamond 500, and detects the fluorescence emitted from the diamond 500 and transmitted through optical waveguides 502, 504, and 510. The power supply unit 522 supplies power to enable the measuring unit 520 to function. The measuring unit 520 and the power supply unit 522 are mounted on a second plate 624 made of a conductive metal. Hereinafter, the environment in which the measuring unit 520 and the power supply unit 522 are mounted will be referred to as the second environment. A predetermined DC voltage, lower than the voltage applied to the first plate 610, is supplied to the second plate 624 via a DC power supply 626.

[0095] pass Figure 10 The diamond spin sensor system shown detects the fluorescence intensity from diamond 500. Two measurement methods (Measurement A and Measurement B described below) are used to measure the magnetic field generated by the current flowing in the wire 614 positioned near diamond 500. Furthermore, the presence or absence of the covering (i.e., heat-shrinkable tube 530) at the connection between diamond 500 and optical waveguide 502, and the difference caused by the applied voltage to the first plate 610 on which diamond 500 is located, are evaluated. In addition, the current flowing through wire 614 can be adjusted by a variable resistor 620 to allow a steady-state current of 1A to flow under applied overvoltage. Experimental results are as follows... Figure 11 As shown. The "Coverage" column indicates whether the optical waveguide 504 is covered or not. The "External Air Isolation of Connector" column indicates whether the heat shrink tube 530 is present or not.

[0096] As determination A, the following phenomenon is used: if the intensity of the excitation source is set constant and the diamond 500 is irradiated, and the fluorescence is observed to detect the magnetic field, the fluorescence intensity will decrease (magnetic field detection only for the excitation source). Since the magnetic field is detected by the change in fluorescence intensity, when the change in fluorescence intensity becomes small and is buried by noise, it is determined that magnetic field detection cannot be performed. As determination B, the following method is used: In Figure 10 The structure is supplemented with a method to irradiate diamond 500 with microwaves. Fluorescence intensity is detected by changing the frequency of the irradiated microwaves, and the interval (frequency difference) of the peaks in the obtained ODMR spectrum is converted into a magnetic field (magnetic field detection based on ODMR spectrum). If the change in fluorescence intensity becomes small and is buried by noise, the spectrum cannot be obtained, and it is determined that magnetic field detection cannot be performed.

[0097] The insulation withstand voltage of the uncoated optical guide and the uncoated optical fiber was pre-confirmed. Direct confirmation of the optical guide or optical fiber confirmed an insulation withstand voltage of 20kV along its length. Even when the optical guide or optical fiber is spirally arranged within a hollow insulator (hole inner diameter approximately 0.2m, hole length approximately 0.6m), an insulation withstand voltage of 20kV can still be confirmed. Regarding the insulation withstand voltage, metal is wound around both ends of the optical guide or optical fiber as test terminals. A voltage is applied between these test terminals; if no current flows more than 0.1mA, it is considered to have an insulation withstand voltage. The low-voltage side plate is sometimes actually grounded (0V), but due to the presence of a drive power supply, etc., it is not always strictly 0V; 10V is always applied in the experiment. Figure 11 In this context, the voltage ratio represents the ratio of the voltage of the first environment (first plate 610) (specifically 10V) to the voltage of the second environment (second plate 624). The current flowing through the wire 614 is adjusted by the variable resistor 620. That is, for each applied overvoltage applied to the first plate 610, the adjustment is made so that a steady-state current of 1A flows in measurement A and a steady-state current of 100mA flows in measurement B.

[0098] Depend on Figure 11 It can be seen that, regardless of whether measurement A or B is performed, the magnetic field generated by the current flowing through the wire 614 can be detected by measuring the fluorescence intensity from the diamond 500. The fluorescence intensity tends to decrease as the magnetic field strength increases (i.e., the higher the voltage supplied from the DC power supply 622). However, when the covered optical waveguide or fiber is used as a waveguide for light (see Experiments No. 9 and No. 11), the increased applied overvoltage will cause leakage current, affecting the excitation source and microwave power supply, thus making stable measurements impossible.

[0099] When comparing uncoated optical waveguides or uncoated optical fibers (refer to Experiments No. 1 to No. 8) with coated optical waveguides or coated optical fibers (refer to Experiments No. 9 to No. 12), differences in insulation durability were observed in both Measurement Method A and Measurement Method B when the voltage ratio was more than three orders of magnitude. That is, the uncoated optical waveguide exhibits higher insulation durability compared to the coated waveguide. Furthermore, when comparing the case where the connection between the diamond 500 and the optical waveguide 502 is covered with heat-shrinkable tubing 530 (refer to Experiments No. 1 to No. 12) with the case where heat-shrinkable tubing 530 is not used (refer to Experiments No. 13 and No. 14), differences were observed even when the connection was contaminated with oil or oil and sand. That is, by using heat-shrinkable tubing 530 for covering, magnetic fields can be stably detected without contamination or damage.

[0100] (First comparative example) As a first comparative example, using a Hall element, in conjunction with Figure 10 Magnetic field measurements were performed under similar voltage conditions. (Refer to...) Figure 12 The Hall element 630 is placed in a first environment (first plate 610), and the drive unit 632 is placed in a second environment (second plate 624). Similar to the first embodiment, the voltage of the second plate 624 is set to a constant (10V), and the voltage of the first plate 610 is varied. The magnetic field generated by the current flowing through the wire 614 is measured by the Hall element 630. The results are shown below. Figure 13 When the voltage ratio is more than one order of magnitude higher (refer to Experiments No. 21 to No. 23), it affects the drive unit 632, resulting in increased noise and malfunctions, making it impossible to measure the magnetic field.

[0101] (Second Embodiment) Experiments were conducted using a connector different from that in the first embodiment. (Refer to...) Figure 14 The diamond spin sensor system involved in the second embodiment includes a diamond 500, an optical waveguide 502, an optical waveguide 544, a reflector 542, a lens 552, an optical waveguide 510, a measuring unit 520, and a power supply unit 522. Figure 14 The structure shown is in Figure 10 In the structure shown, the optical waveguide 504 is replaced by an optical waveguide 544, a reflector 542, and a lens 552, and the optical connector 508 is removed (for the connector portion, see [reference]). Figure 6 Other structures and Figure 10 Since they are the same, we will not repeat the explanation. Figure 15 express Figure 14 Experimental results for the structure shown.

[0102] A 1.5mm diameter optical waveguide is used as the optical waveguide 544. The open first end face 546 of the optical waveguide 544 is positioned at the center of the first opening 908 of the insulator 906, facing the second opening of the insulator 906. The excitation light 540 (laser) output from the measuring unit 520 propagates in the air and is reflected by the reflector 542. The angle of the reflector 542 can be adjusted. By adjusting the angle of the reflector 542, the excitation light 540 is incident on the first end face 546 of the optical waveguide 544 positioned at the center of the first opening 908 of the insulator 906. Thus, the excitation light 540 can propagate in the optical waveguide 544 and the optical waveguide 502 and irradiate the diamond 500.

[0103] Fluorescence 550 emitted from diamond 500 propagates in optical waveguides 502 and 544, emanating from the first end face 546 of optical waveguide 544, and is focused by lens 552 located near the second opening of insulator 906, thus incident on optical waveguide 510. Therefore, as... Figure 15As shown, in either measurement A or measurement B, the fluorescence emitted from the diamond 500 can be detected by the measurement unit 520.

[0104] (Third embodiment) Experiments were conducted using a connector that differed from both the first and second embodiments. (Refer to...) Figure 16 The diamond spin sensor system involved in the third embodiment includes a diamond 500, an optical waveguide 502, an optical waveguide 544, a lens 560, a reflector 542, a lens 552, an optical waveguide 510, a measuring unit 520, and a power supply unit 522. Figure 16 The structure shown is in Figure 14 The structure shown includes an additional lens 560 (refer to the connector section). Figure 6 Lens 560 is disposed within insulator 906 near the first opening 908. Other structures are similar to... Figure 14 Since they are the same, we will not repeat the explanation. Figure 17 express Figure 16 The experimental results for the structure shown are as follows. The column "Lens inside the insulator" indicates the presence or absence of lens 560.

[0105] The excitation light 540 (laser) output from the measuring unit 520 propagates in the air and is reflected by the reflector 542. The angle of the reflector 542 is adjusted so that the excitation light 540 is incident through the lens 560 onto the first end face 546 of the optical waveguide 544 disposed in the center of the first opening 908 of the insulator 906. As a result, the excitation light 540 can propagate in the optical waveguide 544 and the optical waveguide 502 and irradiate the diamond 500.

[0106] Fluorescence 550 emitted from diamond 500 propagates in optical waveguides 502 and 544, emanating from the first end face 546 of optical waveguide 544. It is focused by lenses 560 and 552, located near the first opening 908 of insulator 906, and incident on optical waveguide 510. Thus, as... Figure 17 As shown, in either measurement A or measurement B, the fluorescence emitted from the diamond 500 can be detected by the measurement unit 520.

[0107] (Fourth embodiment) Using the same connector as in the first embodiment, experiments were conducted by varying the temperature of the environment in which the diamond was disposed. (Refer to...) Figure 18 The diamond spin sensor system involved in the fourth embodiment includes a diamond 500, an optical waveguide 502, an optical waveguide 504, an optical waveguide 510, a measuring unit 520, and a power supply unit 522. Figure 18 The diamond spin sensor system shown is Figure 10The diamond spin sensor system shown is the same. Therefore, it will not be described again. However, the environments in which the diamond 500 and the measuring unit 520 are configured are different. That is, in Figure 10 In the structure shown, the DC power supply 626 is removed, and a heater control unit 642 is added.

[0108] A wire 614 is disposed on the stacked first plate 610 and first plate 640, and then a diamond 500 (first environment) covered by a heat-shrinkable tube 530 is disposed thereon. The first plate 640 includes a conductive metal plate and a heater (not shown) that is heated by electricity supplied from a heater control unit 642. The first plate 640 can be heated to 600°C by the heater control unit 642. By conducting an experiment in a vacuum with a portion of the first plate 640 (including the components disposed on the first plate 640) disposed therein, the temperature can be raised to 1000°C. The first plate 640 and the first plate 610 (see reference) Figure 10 Unlike other power supplies, it is not subjected to voltage from DC power supply 622. Additionally, unlike other power supplies... Figure 10 Unlike other systems, no voltage is applied to the second board 624, which is equipped with a measuring unit 520 and a power supply unit 522.

[0109] The insulation and heat resistance of the uncoated optical waveguide or uncoated optical fiber used as the optical waveguide 504 were confirmed in advance. Even when the optical waveguide 504 is spirally arranged in a hollow 0.5m insulator 906, insulation and heat resistance of 1000°C can be confirmed. Insulation and heat resistance means that when the temperature on the diamond sensor side is high, the temperature of the drive power supply section will not rise to a high temperature and will be isolated. Specifically, if the temperature of the second plate 624 in the second environment does not rise by more than 10°C due to the influence of the first plate 640 in the first environment, it is determined that there is insulation and heat resistance. The low-temperature side plate (second plate 624) is actually at room temperature (10°C to 20°C). In the fourth embodiment, a Peltier element is used to keep the low-temperature side plate (second plate 624) at 10°C.

[0110] according to Figure 18 The configuration shown is the same as in the first embodiment, with the magnetic field measured by measurement A and measurement B. Also as in the first embodiment, the current flowing through the wire 614 is adjusted by the variable resistor 620. That is, for each applied overvoltage, the adjustment is made so that a steady-state current of 1A flows in measurement A and a steady-state current of 100mA flows in measurement B. The results are shown below. Figure 19 .exist Figure 19In this diagram, the plate temperature of the first environment refers to the temperature of the first plate 640, and the plate temperature of the second environment refers to the temperature of the second plate 624. As shown in Experiments No. 51 to No. 54, the magnetic field can be measured at any temperature ratio. Furthermore, by using a heat-shrinkable tube 530 to cover the connection between the diamond 500 and the optical waveguide 502, the magnetic field can be detected stably without contamination or damage to the diamond 500.

[0111] (Second comparative example) As a comparative example, experiments were conducted using thermocouples. Figure 18 In the structure shown, a thermocouple is placed in the first environment (first plate 640 and insulating layer 612), and the driving power supply of the thermocouple is placed in the second environment (second plate 624) for temperature measurement. As a result, the temperature of the second environment affects the temperature of the first environment, making it impossible to accurately measure the temperature of the first environment.

[0112] The present disclosure has been described above by way of example, but the above-described embodiments are illustrative and the present disclosure is not limited to the above-described embodiments. The scope of the present disclosure is as set forth in the claims, based on the detailed description of the invention, and includes all modifications within the meaning and scope of the statements herein.

[0113] Explanation of reference numerals in the attached figures 100, 150: Diamond spin sensor system; 102: Sensors Section; 104, 114: Joint section; 106: Power supply control unit; 108, 112, 502, 504, 510, 544: Optical waveguides; 110, 500: Diamond; 120: Excitation light-generating part; 122: Filter; 124: Concentrating element; 126: LPF; 128: Optical Detection Department; 130: Control Department; 140, 142: Connecting parts; 152: Electromagnetic wave generating unit; 154: Microwave connector; 156, 158, 416: Microwave transmission path; 160: Microwave circuits; 200, 400: First Containment Department; 202, 402: Second Containment Department; 204, 404: Third Containment Department; 206: Optical transmission components; 208, 210: Hammer-shaped components; 212, 214, 230: Optical fiber; 216, 218, 314, 316, 506, 508: Optical connectors; 220, 406: Space; 232, 234: Covering parts; 236, 250: Supporting components; 240: Inner wall; 300, 302, 552, 560: Lenses; 304, 540: Excitation light; 306, 550: Fluorescence; 310, 312: Multiple optical fibers; 318, 320: Multi-core fiber optic cables; 410: Sending Department; 412: Receiving Unit; 414: High-frequency cutoff filter; 520: Measurement Department; 522: Power supply section; 530: Heat shrink tubing; 542: Reflector; 546: First end face; 610, 640: First board; 612: Insulation layer; 614: Wire; 620: Variable resistor; 622, 626: DC power supply; 624: Second board; 630: Hall element; 632: Drive unit; 642: Heater control unit; 900: Power transmission line; 902: Iron Tower; 904, 906: Insulators; 908: The first opening; F: Focus.

Claims

1. A diamond spin sensor system, wherein, The diamond spin sensor system includes: The sensor section contains a diamond with a color center having electron spin; The control power supply unit generates excitation light that illuminates the sensor unit; and The connector connects the sensor unit and the control power supply unit. The connector transmits the excitation light to the sensor and irradiates the diamond. The connector transmits the fluorescence emitted by the diamond to the control power supply.

2. The diamond spin sensor system according to claim 1, wherein, The sensor unit is disposed in the first environment. The control power supply is configured in a second environment, which is different from the first environment. The first environment is at least one order of magnitude larger than the second environment in terms of voltage and temperature.

3. The diamond spin sensor system according to claim 1 or 2, wherein, The sensor unit further includes an optical waveguide that transmits the excitation light to the diamond. The optical waveguide is formed of a transparent resin, a transparent nitride, or a transparent oxide. The diamond and the connection between the diamond and the optical waveguide are isolated from the outside air.

4. The diamond spin sensor system according to claim 3, wherein, The joint portion includes an insulator. The insulator has a structure inside the insulator that allows the excitation light to pass through.

5. The diamond spin sensor system according to claim 4, wherein, An uncovered light transmission component is disposed inside the connector to allow the excitation light to pass through, or A space is formed inside the connector to allow the excitation light to pass through.

6. The diamond spin sensor system according to claim 5, wherein, The space is formed inside the joint portion, and The connector has a lens inside that allows the excitation light to pass through.

7. The diamond spin sensor system according to claim 6, wherein, The diamond spin sensor system has multiple optical fibers that transmit the fluorescence emitted from the diamond and direct the fluorescence to the lens. The multiple optical fibers were bundled together.

8. The diamond spin sensor system according to claim 1 or 2, wherein, The joint portion includes an insulator. The insulator has a structure inside the insulator that allows the excitation light to pass through.

9. The diamond spin sensor system according to any one of claims 1 to 3 and 8, wherein, An uncovered light transmission component is disposed inside the connector to allow the excitation light to pass through.

10. The diamond spin sensor system according to any one of claims 1 to 3 and 8, wherein, The interior of the connector has a space for the excitation light to pass through.

11. The diamond spin sensor system according to any one of claims 1 to 10, wherein, The diamond spin sensor system also includes: Electromagnetic wave generator, outputting microwaves; and Microwave connector, The sensor unit includes microwave circuitry or microwave waveguides. The microwave connector includes: The transmitting unit radiates microwaves input from the electromagnetic wave generating unit; as well as The receiving unit receives the microwaves emitted from the transmitting unit. The microwave received by the receiving unit is output to the microwave circuit or microwave waveguide included in the sensor unit. A space is formed in the microwave connector for the propagation of microwaves emitted by the transmitting unit.

12. The diamond spin sensor system according to claim 11, wherein, The transmitting unit includes a first concave surface that radiates the microwaves. The receiving part includes a second concave surface that focuses the microwaves. The first concave surface and the second concave surface are each part of a parabola or a sphere.

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