Optical measurement head, endoscope, and optical measurement method

Abstract

The present invention achieves measurement of an object by using visible light and infrared light. The present invention comprises: a substrate (S) that is composed of diamond and has a color center-containing layer (Ly) containing a color center for measuring the state of an object (OB); and a light input / output unit (11) that faces or is in contact with the substrate, emits excitation light (Le) for exciting the color center, receives fluorescence (Lf) from the color center excited by the excitation light, emits infrared light (Li) to the object via the substrate, and receives infrared light reflected by the object.

Description

Optical measurement head, endoscope, and optical measurement method

[0001] The present invention relates to an optical measurement head, an endoscope, and an optical measurement method.

[0002] Techniques for performing physicochemical measurements using NV centers are known (see Non-Patent Document 1). Non-Patent Document 1 discloses a technique for measuring pH using NV centers in diamond. In this measurement, for example, visible excitation light (wavelength: 532 nm) and fluorescence (wavelength: 700 nm) are used.

[0003] T. Fujisaku et al., pH Nanosensor Using Electronic Spins in Diamond, ACS Nano 2019, 13, 10, 11726-11732

[0004] In this context, infrared light is sometimes used to observe objects. For example, in cancer screening, infrared light with a wavelength of 8 to 11 μm is used to observe objects (e.g., collected biological tissue) under a microscope, making it possible to distinguish between normal and abnormal areas.

[0005] By combining observation using infrared light with measurement using an NV center, it becomes possible to more accurately understand the state of the object.

[0006] However, it is not easy to measure a single object simultaneously at multiple wavelengths that are different from each other. For example, glass (N-BK7) transmits visible light but hardly transmits light with wavelengths of 3 μm or more. Also, barium fluoride (BaF) ２ ) only transmits light in a range of about 2 to 5 μm. Thus, there are few optical materials (window materials) that transmit both visible light and infrared light.

[0007] One aspect of the present invention aims to enable the measurement of an object using visible light and infrared light.

[0008] To solve the above problems, an optical measuring head according to one aspect of the present invention comprises a substrate made of diamond and having a color center-containing layer containing color centers for measuring the state of an object, and an optical input / output unit facing or in contact with the substrate, which emits excitation light to excite the color centers, receives fluorescence from the color centers excited by the excitation light, emits infrared light to the object via the substrate, and receives infrared light reflected by the object.

[0009] To solve the above problems, an optical measurement method according to one aspect of the present invention is an optical measurement method for optically measuring the state of an object, comprising: an incidence step of incidentally injecting excitation light and infrared light into a substrate made of diamond and having a color center-containing layer, the excitation light that excites the color centers and the infrared light that is incident on the object via the substrate and reflected, and is emitted.

[0010] According to one aspect of the present invention, it is possible to measure an object using visible light and infrared light.

[0011] This is a block diagram showing an example of an optical measurement system according to Embodiment 1 of the present invention. This is a schematic diagram showing the level of the NV center. This is a block diagram showing an example of an optical measurement system according to Embodiment 2 of the present invention. This is a schematic diagram showing an example of an optical measurement head according to Embodiment 3 of the present invention. This is a schematic diagram showing an example of an optical measurement system according to Embodiment 4 of the present invention. This is a schematic diagram showing an example of an optical measurement system according to Embodiment 5 of the present invention. This is a plan view showing an example of a substrate for an optical measurement system according to Embodiment 5 of the present invention. This is a schematic diagram showing an example of an endoscope according to Embodiment 5 of the present invention. This is a diagram showing an optical measurement head according to a modified example.

[0012] [Embodiment 1] An embodiment of the present invention will be described in detail below. Figure 1 is a block diagram showing an example of an optical measurement system 1 according to Embodiment 1 of the present invention.

[0013] The optical measurement system 1 includes an optical measurement head 10, beam splitters 21a to 21c, a filter 22, light sources 23a to 23c, and photodetectors 24a to 24c, and measures the target object OB.

[0014] The optical measurement head 10 is used to measure and observe the object OB by approaching or contacting the object OB using light (excitation light Le, fluorescence Lf, infrared light Li, visible light Lv). Hereinafter, measurement and observation will be collectively referred to as measurement. The wavelengths of the excitation light Le, fluorescence Lf, and visible light Lv are in the visible range (for example, 360 to 830 nm), and the wavelength of the infrared light Li is in the mid-infrared range (for example, 1 to 20 μm).

[0015] The optical measurement head 10 has a substrate S and an optical input / output section 11. The optical input / output section 11 is a component having a first passage section (first optical input / output section) 11a through which excitation light Le and fluorescence Lf pass, a second passage section (second optical input / output section) 11b through which infrared light Li passes, and a third passage section (third optical input / output section) 11c through which visible light Lv passes.

[0016] The substrate S is made of plate-shaped diamond and has a layer Ly containing color centers (e.g., nitrogen-vacancy centers (hereinafter also referred to as NV centers)) for measuring the state of the object OB. By making the substrate S out of diamond, it is possible to pass visible excitation light Le, fluorescence Lf, visible light Lv, and infrared light Li through it, and the substrate S can be used as a window material for measuring and observing the object OB. The object OB can be observed using infrared light Li and visible light Lv, and the state of the object OB (e.g., at least one of pH, magnetic field, and radicals) can be measured based on the fluorescence Lf from the color centers.

[0017] When the color center is an NV center, for example, it can be formed by accelerating nitrogen ions and implanting them into the substrate S. The color center-containing layer Ly is preferably formed at a depth d (for example, about 50 nm) within about 1 μm from the surface of the substrate S on the object OB side. By bringing the object OB close to the color center-containing layer Ly, for example, it becomes easy to measure the pH of the object OB. For example, by changing the acceleration energy (eV) of nitrogen ions, the depth of the NV center-containing layer Ly can be adjusted.

[0018] FIG. 2 is a schematic diagram showing the energy levels of the NV center. As shown in FIG. 2, the NV center has a ground state ３ A ２ and an excited state ３ E. The ground state ３ A ２ is divided into two magnetic sublevels ms = 0, ms = ±1. The NV center is excited by excitation light Le (wavelength: 532 nm) from the ground state ３ A ２ (ms = 0, ms = ±1) to the excited state [[ID=第十八条]] ３ [[ID=第十九条]]E (paths T11, T12). The NV center emits fluorescence Lf (wavelength: 637 nm) and transitions from the excited state ３ E to the ground state ３ A ２ . Note that depending on whether the original ground state ３ A ２ is in the magnetic sublevel ms = 0 or ms = ±1, the intensity of the fluorescence Lf is different. There is also a path from the excited state ３ E to the ground state ３ A ２ via a metastable state Sm, and in this case, it is a non-radiative transition where no fluorescence is emitted.

[0019] By applying microwaves to the NV center, the intensity of fluorescence Lf decreases at frequencies corresponding to the energy difference between magnetic sub-levels ms=0 and ms=±1 (photodetected magnetic resonance). Since this resonance frequency depends on, for example, temperature and magnetic field, temperature and magnetic field can be measured. Furthermore, because the resonance frequencies of temperature and magnetic field shift in different directions, temperature and magnetic field can be measured simultaneously using excitation light Le and fluorescence Lf.

[0020] Thus, it is preferable to enable the application of microwaves to the NV center for various measurements. For this reason, it is conceivable to place a high-frequency field radiating member, such as an antenna, which radiates a high-frequency electric field, near the optical measurement head 10. Alternatively, the optical measurement head 10 may also be equipped with a high-frequency field radiating member. Details of this will be described later.

[0021] Furthermore, it is preferable to perform chemical surface modification on the surface of the substrate S facing the object OB. Chemical surface modification can improve the reliability of measuring the object OB. Examples of chemical surface modification include carboxylation and HPG formation.

[0022] The optical measurement head 10 includes an optical input / output unit 11. The optical input / output unit 11 faces or is in contact with the substrate S. In this example, the optical input / output unit 11 is positioned facing the substrate S and exchanges light with the substrate S via optical lenses Lza to Lzc.

[0023] The optical input / output unit 11 emits excitation light Le to excite the color center, and fluorescence Lf from the color center is incident on it. The optical input / output unit 11 emits infrared light Li to the object OB via the substrate S, and infrared light Li reflected from the object OB is incident on it. The optical input / output unit 11 emits visible light Lv to the object OB via the substrate S, and visible light Lv reflected from the object OB is incident on it.

[0024] The optical input / output unit 11 can be divided into the following first to third optical input / output units: (1) One or more first optical input / output units 11a that emit excitation light Le and into which fluorescence Lf is incident; (2) One or more second optical input / output units 11b that emit infrared light Li and into which infrared light Li reflected by the object OB is incident; (3) One or more third optical input / output units 11c that emit visible light Lv and into which visible light Lv reflected by the object OB is incident.

[0025] Here, the first to third optical input / output units 11a to 11c are each one, but the first to third optical input / output units 11a to 11c may each be multiple. Also, the optical input / output unit 11 does not have to include all of the first to third optical input / output units 11a to 11c. For example, the optical input / output unit 11 may include only the first and second optical input / output units 11a and 11b. In this case, the optical input / output unit 11 includes the third optical input / output unit 11c, making it easy to observe the object using visible light Lv.

[0026] Optical lenses Lza to Lzc are positioned between the optical input / output unit 11 and the substrate S to focus light between the optical input / output unit 11 and the substrate S. Here, the optical measurement head 10 has three optical lenses Lza to Lzc, which are positioned along the optical axes of (a) excitation light Le and fluorescence Lf, (b) infrared light Li, and (c) visible light Lv, respectively. Optical lenses Lza, Lzb, and Lzc have optical properties corresponding to (a) excitation light Le and fluorescence Lf, (b) infrared light Li, and (c) visible light Lv, respectively.

[0027] The beam splitter 21a receives excitation light Le from the light source 23a and emits it toward the substrate S, and receives fluorescence Lf from the substrate S and emits it separately from the excitation light Le from the light source 23a. Similarly, the beam splitter 21b receives infrared light Li from the light source 23b and emits it toward the substrate S, and receives infrared light Li from the substrate S and emits it separately from the infrared light Li from the light source 23b. The beam splitter 21c receives visible light Lv from the light source 23c and emits it toward the substrate S, and receives visible light Lv from the substrate S and emits it separately from the visible light Lv from the light source 23c.

[0028] Filter 22 is a wavelength-selective filter that blocks the excitation light Le and allows the fluorescence Lf to pass through.

[0029] Light sources 23a to 23c are light sources that emit excitation light Le, infrared light Li, and visible light Lv, respectively. Of these, light source 23a is preferably a pulsed laser light source that emits pulsed laser light at a predetermined period.

[0030] Photodetectors 24a to 24c are detectors that detect fluorescence Lf, infrared light Li, and visible light Lv, respectively.

[0031] The excitation light Le from the light source 23a is emitted, for example, as a pulsed laser, and enters the substrate S and ultimately the color center-containing layer Ly via the beam splitter 21a and optical lens Lz, exciting the color centers. The excited color centers emit fluorescence Lf, which enters the photodetector 24a via the optical lens Lz, beam splitter 21a, and filter 22.

[0032] Infrared light Li from light source 23b passes through the substrate S via beam splitter 21b and optical lens Lz and is incident on object OB. The infrared light Li reflected from object OB is incident on photodetector 24b via substrate S, optical lens Lz, and beam splitter 21b.

[0033] Visible light Lv from light source 23c passes through the substrate S via beam splitter 21c and optical lens Lz and is incident on object OB. Visible light Lv reflected from object OB is incident on photodetector 24c via substrate S, optical lens Lz, and beam splitter 21c.

[0034] As described above, the optical measurement head 10 according to Embodiment 1 comprises a substrate S made of diamond and having a color center-containing layer Ly for measuring the state of an object OB, and an optical input / output unit 11 facing or in contact with the substrate S, which emits excitation light Le to excite color centers, receives fluorescence Lf from the color centers excited by the excitation light Le, emits infrared light Li to the object OB via the substrate S, and receives infrared light Li reflected by the object OB.

[0035] Further, the optical measurement method according to Embodiment 1 is an optical measurement method for optically measuring the state of an object OB, and excitation light Le for exciting color centers and infrared light Li are incident on a substrate S composed of diamond and having a color center-containing layer Ly. The method includes an incident step of causing the light to enter, and an emission step of emitting fluorescence Lf from the color centers excited by the excitation light Le and infrared light Li that has been incident on the object through the substrate S and reflected therefrom, from the substrate S.

[0036] Diamond has a wide transmission range from the visible region to the infrared region and can form color centers. This facilitates the measurement of the state of the object OB using the excitation light Le and the fluorescence Lf, and the observation of the object OB using the infrared light Li.

[0037] [Embodiment 2] Another embodiment of the present invention will be described below. For the sake of convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

[0038] FIG. 3 is a block diagram showing an example of an optical measurement system 1 according to Embodiment 2 of the present invention. The optical measurement system 1 includes an optical measurement head 10, optical fibers Fa to Fc, optical circulators 25a to 25c, optical fibers Fa1 to Fc2, a filter 22, light sources 23a to 23c, and photodetectors 24a to 24c, and measures an object OB.

[0039] The optical measurement head 10 includes one or more optical fibers. Here, a part of the optical fibers Fa to Fc functions as an optical input / output unit 11. One end of each of the optical fibers Fa to Fc is connected to the substrate S, and exchanges excitation light Le, fluorescence Lf, infrared light Li, and visible light Lv with the substrate S. That is, here, the optical input / output unit 11 contacts the substrate S.

[0040] Optical circulator 25a emits light incident from optical fiber Fa1 (excitation light Le) to optical fiber Fa, and emits light incident from optical fiber Fa (fluorescence Lf) to optical fiber Fa2. Similarly, optical circulator 25b emits light incident from optical fiber Fb1 (infrared light Li) to optical fiber Fb, and emits light incident from optical fiber Fb (infrared light Li) to optical fiber Fb2. Optical circulator 25c emits light incident from optical fiber Fc1 (visible light Lv) to optical fiber Fc, and emits light incident from optical fiber Fc (visible light Lv) to optical fiber Fc2.

[0041] As described above, optical fibers may be used to inject and emit light onto the substrate S.

[0042] [Embodiment 3] Another embodiment of the present invention will be described below. For the sake of convenience of explanation, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0043] Figure 4 is a schematic diagram showing an example of an optical measurement head according to Embodiment 3 of the present invention. Here, optical fibers Fa, Fb1, Fb2, and Fc function as optical input / output units 11. Optical fiber Fa (optical input / output unit 11) emits excitation light Le along a first axis and is incident on fluorescent light Lf. Optical fiber Fb1 (optical input / output unit 11) emits infrared light Li along a second axis different from the first axis, and optical fiber Fb2 (optical input / output unit 11) is incident on infrared light Li reflected from the object OB along a third axis different from both the first and second axes. Optical fiber Fc (optical input / output unit 11) emits visible light Lv along a fourth axis different from all of the first to third axes and is incident on visible light Lv reflected from the object OB.

[0044] The optical measurement head 10 has a substrate Sc. The substrate Sc has first to third reflectors RF1 to RF3. The first reflector RF1 reflects infrared light Li incident into the substrate Sc (at a reflection angle θ1). The second reflector RF2 reflects the infrared light Li reflected by the first reflector RF1 (at a reflection angle θ2). The third reflector RF3 reflects the infrared light Li reflected by the second reflector RF2 (at a reflection angle θ3). That is, infrared light Li emitted from the light source 23b and incident into the substrate Sc via the optical fiber Fb1 is reflected by the reflectors RF1 to RF3 and incident into the optical fiber Fb2.

[0045] The second reflector RF2 totally reflects infrared light. That is, the reflection angle θ2 of infrared light Li at the second reflector RF2 is greater than the critical angle θ0 (θ2 > θ0). At this time, evanescent light Ev seeps out of the substrate Sc from the second reflector RF2. A portion of this evanescent light Ev is reflected by the object OB and returns to the substrate Sc. The third reflector RF3 seeps out from the second reflector RF2 and reflects the evanescent light Ev reflected by the object OB. In this way, it becomes easy to measure approximately the same location on the object OB using the evanescent light Ev with excitation light Le (fluorescence Lf), infrared light Li, and visible light Lv.

[0046] The excitation light Le from the light source 23a is emitted via the optical fiber Fa and incident on the color center, and the fluorescence Lf from the color center is incident on the photodetector 24a via the optical fiber Fa. Note that the beam splitter 21a and filter 22 are omitted in this description.

[0047] Infrared light Li from light source 23b is emitted via optical fiber Fb1, passes through substrate Sc, and enters the target object OB. The infrared light Li reflected from target object OB enters the photodetector 24b via optical fiber Fb2. Note that the beam splitter 21b is omitted in this description.

[0048] Visible light Lv from light source 23c is emitted via optical fiber Fc, passes through substrate Sc, and enters the target object OB. The visible light Lv reflected from target object OB enters the photodetector 24c via optical fiber Fc. Note that the beam splitter 21c is omitted in this description.

[0049] As described above, by shaping the substrate Sc to form reflective sections RF1 and RF3, and by causing total internal reflection of light at reflective section RF2, it becomes possible to measure the object OB using excitation light Le and fluorescence Lf, and observe it using infrared light Li and visible light Lv at approximately the same location on the object OB.

[0050] [Embodiment 4] Another embodiment of the present invention will be described below. For the sake of convenience of explanation, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated. Figure 5 is a schematic diagram showing an example of an optical measurement system 1 according to Embodiment 4 of the present invention.

[0051] The optical measurement system 1 includes n filters 22, light sources 23a to 23c, photodetectors 24a to 24c, optical circulators 25a to 25c, and optical fibers Fa to Fc. Filter 22 is a collective term for filters 22(1) to 22(n). Optical fibers Fa to Fc are collective terms for optical fibers Fa(1) to Fa(n), Fb(1) to Fb(n), and Fc(1) to Fc(n), respectively.

[0052] Each optical fiber Fa(1) to Fa(n) is single-core and is connected to the cores Ca(1) to Ca(n) of the multi-core fiber FMa, respectively. Similarly, each single-core optical fiber Fb(1) to Fb(n) is connected to the cores Cb(1) to Cb(n) of the multi-core fiber FMb, respectively. Each single-core optical fiber Fc(1) to Fc(n) is connected to the cores Cc(1) to Cc(n) of the multi-core fiber FMc, respectively.

[0053] In other words, the optical measurement system 1 according to Embodiment 4 includes multicore optical fibers FMa to FMc, where each multicore optical fiber FMa to FMb has n first cores Ca(1) to Ca(n) that function as a plurality of first optical input / output units 11a, and n second cores Cb(1) to Cb(n) that function as a plurality of second optical input / output units 11b (n: an integer of 2 or more). Furthermore, the multicore optical fiber FMc has n third cores Cc(1) to Cc(n) that function as a plurality of third optical input / output units 11c. Here, multiple optical fibers FMa to FMc are used, but these optical fibers FMa to FMc may be combined into a single multicore optical fiber.

[0054] In this way, it becomes possible to measure the object's outbound path (OB) at multiple locations using excitation light Le and fluorescence Lf, and to observe it using infrared light Li and visible light Lv. For example, the results of observation and measurement can be represented as an image corresponding to the location on the object's OB.

[0055] [Embodiment 5] Another embodiment of the present invention will be described below. For the sake of convenience of explanation, components having the same function as those described in the above embodiments will be denoted by the same reference numerals, and their descriptions will not be repeated. Figure 6 is a schematic diagram showing an example of an optical measurement system 1 according to Embodiment 5 of the present invention. Figure 7 is a plan view showing an example of a substrate S of the optical measurement system 1 according to Embodiment 5 of the present invention.

[0056] Here, the ends of optical fibers Fa(1) to Fa(n), Fb(1) to Fb(n), and Fc(1) to Fc(n) are each arranged within relatively narrow regions A(1) to A(n) on the substrate S. For example, the ends of optical fibers Fa(i) to Fc(i) are arranged within region A(i) on the substrate S. As shown in Figure 7, regions A(1) to A(n) are arranged in a matrix on the plane of the substrate S. As a result, the distribution of measurement results on the object OB can be obtained.

[0057] In other words, in the optical measurement system 1 according to Embodiment 5, the substrate S has n regions A(1) to A(n) that divide the surface of the substrate. In each of the n regions A(1) to A(n) (region A(i)), one first core Ca(i) from the n first cores Ca(1) to Ca(n) and one second core Cb(i) from the n second cores Cb(1) to Cb(n) are arranged. In addition, in each of the n regions A(1) to A(n), one third core Cc(i) from the n third cores Cc(1) to Cc(n) are arranged.

[0058] By doing so, it becomes easy to clearly display the following results as corresponding images of the object: (1) the measurement results of the object's out-of-bounds (OB) using excitation light Le and fluorescence Lf, (2) the observation results of the object's OB using infrared light Li, and (3) the observation results of the object's OB using visible light Lv.

[0059] [Embodiment 6] Figure 8 is a schematic diagram showing an example of an endoscope 50 according to Embodiment 6 of the present invention. The endoscope 50 includes a housing 51, a light guide 52, a camera 53, an air / water supply nozzle 54, a suction / forceps channel 55, and an optical measurement head 10.

[0060] The housing 51 houses various mechanisms and protects them from the outside world. The light guide 52 illuminates the target object OB (in this case, the inside of a living organism) with light, and the camera 53 has an objective lens and photographs the target object OB. The air / water supply nozzle 54 supplies water or air to the inside of the living organism, making it easier to observe the target object OB.

[0061] The suction / forceps port 55 is an opening for aspirating water or air, or for removing treatment instruments 56. The treatment instruments 56 are instruments for collecting biological tissue and performing various procedures (treatment, hemostasis, foreign body retrieval).

[0062] The optical measurement head 10 is used to measure and observe the object OB using the substrate S as a window material. As described above, the substrate S may be connected to the end of an optical fiber, enabling measurement by a light source and a photodetector. Alternatively, fluorescence may be observed using an objective lens (for example, a microscope) instead of an optical fiber.

[0063] The endoscope 50, equipped with an optical measurement head 10, can measure the pH and ion concentration within the body, making it easier to detect, for example, the early stages of a tumor. Because the optical fiber is flexible, it can function as an endoscope even in environments with obstacles.

[0064] [Modified Version] Figure 9 shows a modified optical measurement head 10. This optical measurement head 10 has a high-frequency field radiation member 12 for applying a high-frequency electric field to the color center. The high-frequency field radiation member 12 is positioned near the object OB and applies high frequency (microwave) from the high-frequency oscillator 26 to the object OB. By applying microwaves to the object OB (NV center), it becomes possible to measure optically detected magnetic resonance. The high-frequency field radiation member 12 is, for example, a loop antenna positioned on the outer circumference of the optical fiber Fa. Since it is sufficient to apply the high frequency near the tip of the optical fiber Fa, it does not need to be positioned on the optical fibers Fb and Fc. The high-frequency field radiation member 12 may also be added to the multicore optical fiber FMa shown in Figure 5.

[0065] (Summary) The optical measuring head according to the first embodiment comprises: a substrate made of diamond and having a color center containing a color center layer containing a color center for measuring the state of an object; and an optical input / output unit facing or in contact with the substrate, which emits excitation light to excite the color center, receives fluorescence from the color center excited by the excitation light, emits infrared light to the object via the substrate, and receives infrared light reflected by the object.

[0066] Diamonds have a wide transmission range from visible light to infrared light and can form color centers. This makes it easier to measure the state of an object using excitation light and fluorescence, and to observe the object using infrared light.

[0067] The optical measurement head according to the second embodiment is an optical measurement head according to the first embodiment, wherein the substrate has a first reflecting portion that reflects infrared light incident into the substrate, a second reflecting portion that reflects the infrared light reflected by the first reflecting portion, and a third reflecting portion that reflects the infrared light reflected by the second reflecting portion, wherein the second reflecting portion totally reflects the infrared light, and the third reflecting portion seeps out from the second reflecting portion and reflects the evanescent light reflected by the object.

[0068] This makes it possible to observe objects using evanescent light in the infrared region.

[0069] The optical measurement head according to the third embodiment is an optical measurement head according to the first or second embodiment, wherein the optical input / output unit emits the excitation light and receives the fluorescence along a first axis, emits the infrared light along a second axis different from the first axis, and receives the infrared light reflected from the object along a third axis different from both the first and second axes.

[0070] This makes it possible to inject and emit excitation light and fluorescence along the first axis, emit infrared light along the second axis, and inject infrared light along the third axis. Therefore, by arranging the excitation light / fluorescence and infrared light on different axes, it becomes easy to measure and observe approximately the same location on an object using both excitation light / fluorescence and infrared light.

[0071] The optical measurement head according to the fourth embodiment is an optical measurement head according to any of the first to third embodiments, wherein the optical input / output unit comprises: one or more first optical input / output units that emit the excitation light and into which the fluorescence is incident; and one or more second optical input / output units that emit the infrared light and into which the infrared light reflected by the object is incident.

[0072] This makes it possible to measure one or more points on an object using one or more first optical input / output units and one or more second optical input / output units.

[0073] The optical measurement head according to the fifth embodiment is an optical measurement head according to the fourth embodiment, wherein the optical input / output unit comprises one or more third optical input / output units that emit visible light and into which the visible light reflected by the object is incident.

[0074] This enables measurement of one or more points on an object using excitation light, fluorescence, infrared light, and visible light, by using one or more first optical input / output units, one or more second optical input / output units, and one or more third optical input / output units.

[0075] The optical measurement head according to the sixth embodiment includes one or more optical lenses disposed between the optical input / output unit and the substrate, in the optical measurement head according to the fourth or fifth embodiment.

[0076] This allows light to be focused onto an object using one or more optical lenses.

[0077] The optical measurement head according to the seventh embodiment is an optical measurement head according to the fourth or fifth embodiment, wherein the optical input / output unit includes one or more optical fibers.

[0078] This allows light to be focused onto an object using one or more optical fibers.

[0079] The optical measurement head according to the eighth embodiment is an optical measurement head according to the seventh embodiment, wherein the one or more optical fibers include a multicore optical fiber, and the multicore optical fiber has n first cores that function as a plurality of first optical input / output units, and n second cores that function as a plurality of second optical input / output units (n: an integer of 2 or more).

[0080] This allows for the efficient focusing of light onto multiple points on an object using multi-core optical fibers.

[0081] The optical measurement head according to the ninth embodiment is an optical measurement head according to the eighth embodiment, wherein the multicore optical fiber has n third cores that function as a plurality of third optical input / output units.

[0082] This allows for the efficient focusing of excitation light, infrared light, and visible light onto multiple points on an object using a multi-core optical fiber.

[0083] The optical measuring head according to the tenth embodiment is an optical measuring head according to the eighth embodiment, wherein the substrate has n regions that divide the surface of the substrate, and one first core from the n first cores and one second core from the n second cores are arranged in each of the n regions.

[0084] This allows each of the n regions of the object to be measured using excitation light, fluorescence, and infrared light. As a result, images (1) and (2) can be obtained in a common region that represent the distribution of the measurement results for (1) excitation light, fluorescence, and (2) infrared light.

[0085] The optical measuring head according to the 11th embodiment is an optical measuring head according to the 9th embodiment, wherein the substrate has n regions that divide the surface of the substrate, and one first core from the n first cores, one second core from the n second cores, and one third core from the n third cores are arranged in each of the n regions.

[0086] This allows each of the n regions of the object to be measured using excitation light, fluorescence, infrared light, and visible light. As a result, images (1) to (3) of a common region can be obtained, which represent the distribution of the measurement results for (1) excitation light, fluorescence, (2) infrared light, and (3) visible light.

[0087] The optical measurement head according to the twelfth embodiment is an optical measurement head according to any of the first to eleventh embodiments, wherein the optical measurement head measures at least one of pH, magnetic field, and radicals based on fluorescence from the color center.

[0088] This allows for the measurement of at least one of the object's pH, magnetic field, and radicals.

[0089] The optical measurement head according to the 13th embodiment is an optical measurement head according to any of the first to 12 embodiments, and is equipped with a high-frequency field radiating member for applying a high-frequency electric field to the color center.

[0090] By applying a high-frequency electric field (e.g., microwaves) to the color center, various measurements become possible.

[0091] The optical measurement head according to the 14th embodiment is an optical measurement head according to any of the 1st to 13th embodiments, wherein the color center is a nitrogen-vacancy center.

[0092] Various measurements become possible using nitrogen-vacancy centers.

[0093] The endoscope according to the 15th embodiment is equipped with an optical measuring head according to any of the 1st to 14th embodiments.

[0094] Using an endoscope, it becomes possible to measure the state of an object within the body using excitation light and fluorescence, and to observe the object using infrared light.

[0095] The optical measurement method according to the 16th embodiment is an optical measurement method for optically measuring the state of an object, comprising: an incidence step of incidentally injecting excitation light and infrared light into a substrate made of diamond and having a color center-containing layer containing color centers; and an emission step of causing fluorescence from the color centers excited by the excitation light and infrared light that has been incident on the object via the substrate and reflected to be emitted from the substrate.

[0096] This makes it easier to measure the state of an object using excitation light and fluorescence, and to observe the object using infrared light.

[0097] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0098] 1 Optical measurement system 10 Optical measurement head 11 Optical input / output section S Substrate Ly Color center containing layer RF1-RF3 Reflector Lz Optical lens Fa-Fc Optical fiber Ca-Cc Core FMa-FMc Multicore optical fiber 21a, 21b, 21c Beam splitter 22 Filter 23a, 23b, 23c Light source 24a, 24b, 24c Photodetector 25a, 25b, 25c Optical circulator 50 Endoscope

Claims

1. An optical measuring head comprising: a substrate made of diamond and having a color center-containing layer containing color centers for measuring the state of an object; and an optical input / output unit facing or in contact with the substrate, which emits excitation light to excite the color centers, receives fluorescence from the color centers excited by the excitation light, emits infrared light to the object via the substrate, and receives infrared light reflected by the object.

2. The optical measuring head according to claim 1, wherein the substrate has a first reflecting portion that reflects infrared light incident into the substrate, a second reflecting portion that reflects the infrared light reflected by the first reflecting portion, and a third reflecting portion that reflects the infrared light reflected by the second reflecting portion, the second reflecting portion totally reflects the infrared light, and the third reflecting portion seeps out from the second reflecting portion and reflects the evanescent light reflected by the object.

3. The optical input / output unit emits the excitation light and receives the fluorescence along a first axis, emits the infrared light along a second axis different from the first axis, and receives the infrared light reflected from the object along a third axis different from both the first and second axes, according to claim 1 or 2.

4. The optical measurement head according to claim 1, wherein the optical input / output unit comprises one or more first optical input / output units that emit the excitation light and into which the fluorescence is incident, and one or more second optical input / output units that emit the infrared light and into which the infrared light reflected by the object is incident.

5. The optical input / output unit comprises one or more third optical input / output units that emit visible light and into which the visible light reflected by the object is incident, the optical measuring head according to claim 4.

6. The optical measuring head according to claim 4 or 5, comprising one or more optical lenses disposed between the optical input / output unit and the substrate.

7. The optical measurement head according to claim 4 or 5, wherein the optical input / output unit includes one or more optical fibers.

8. The optical measuring head according to claim 7, wherein the one or more optical fibers include a multicore optical fiber, and the multicore optical fiber has n first cores that function as a plurality of first optical input / output units, and n second cores that function as a plurality of second optical input / output units (n: an integer of 2 or more).

9. The optical measuring head according to claim 8, wherein the multicore optical fiber has n third cores that function as a plurality of third optical input / output units.

10. The optical measuring head according to claim 8, wherein the substrate has n regions that divide the surface of the substrate, and one first core from the n first cores and one second core from the n second cores are arranged in each of the n regions.

11. The optical measuring head according to claim 9, wherein the substrate has n regions that divide the surface of the substrate, and one first core from the n first cores, one second core from the n second cores, and one third core from the n third cores are arranged in each of the n regions.

12. The optical measuring head according to claim 1 or 2, wherein the optical measuring head is for measuring at least one of pH, magnetic field, and radicals based on fluorescence from the color center.

13. The optical measuring head according to claim 1 or 2, further comprising a high-frequency field radiating member for applying a high-frequency electric field to the color center.

14. The optical measuring head according to claim 1 or 2, wherein the color center is a nitrogen-vacancy center.

15. An endoscope comprising the optical measuring head according to claim 1 or 2.

16. An optical measurement method for optically measuring the state of an object, comprising: an incidence step of incidentally injecting excitation light and infrared light into a substrate made of diamond and having a color center-containing layer containing color centers; and an emission step of causing fluorescence from the color centers excited by the excitation light and infrared light that has been incident on the object via the substrate and reflected to be emitted from the substrate.

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