Light measuring apparatus and light measuring method

Abstract

To provide a light measuring apparatus and a light measuring method which are downsizable and able to measure a minute measuring target range with high accuracy.SOLUTION: The light measuring apparatus comprises: a light source irradiating an analyte with irradiation light, detecting the light intensity of analyte light from the analyte, and outputting the irradiation light; a first light guide fiber guiding the irradiation light to the analyte; a second light guide fiber having a larger core diameter than the core diameter of the first light guide fiber and guiding the light from the analyte; an optical fiber probe having a member for fixing the positions of the first light guide fiber and the second light guide fiber; and a measuring instrument detecting the light intensity of the analyte light. The light measuring method according to another aspect of the present invention includes: irradiating the analyte with irradiation light, detecting the light intensity of light from the analyte, and guiding irradiation light from the light source to the first light guide fiber fixed at a reference position of one fixed member to irradiate the analyte therewith; guiding the analyte light from the analyte to the second light guide fiber having a larger core diameter than the core diameter of the first light guide fiber with the measuring instrument; and detecting the light intensity of the analyte light.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light measurement device and a light measurement method. [Background technology]

[0002] Optical measurement devices and optical measurement methods (hereinafter referred to as "optical measurement devices") are widely used, which irradiate a measurement object with light, generate and measure fluorescence based on the irradiated light, and analyze the components and characteristics of the measurement object.

[0003] In the field of optical measurement devices, for example, Patent Document 1 below discloses a multi-core optical fiber probe for ATR spectroscopy that includes an incident-side optical fiber that guides light from a light source to a sample to be measured, a light-receiving-side optical fiber that guides light reflected from the sample to a light-receiving device, and a crystal that is arranged between these optical fibers and whose detection surface contacts the measurement sample. In particular, in the technology described in Patent Document 1 below, the incident-side optical fiber and the light-receiving-side optical fiber each include multiple optical fibers, which are arranged along the longitudinal direction of the crystal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-47017 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 requires the provision of a crystal that is in contact with the object to be measured, and the optical fiber on the incident side and the optical fiber on the receiving side must each be arranged along their longitudinal direction. This means that the object to be measured must be wide, making it difficult to measure a very small area with high accuracy, and the device itself must be large.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an optical measurement device and an optical measurement method that can be miniaturized and that can accurately measure even a minute measurement range. [Means for solving the problem]

[0007] An optical measurement device according to one aspect of the present invention that solves the above-mentioned problems is an optical measurement device that irradiates an irradiation light onto a subject and detects the light intensity of the specimen light from the subject, and includes: a light source that outputs the irradiation light; a first optical fiber that guides the irradiation light to the subject; a second optical fiber that has a core diameter larger than the core diameter of the first optical fiber and guides the specimen light from the subject; an optical fiber probe that has a single fixing member that fixes the first optical fiber and the second optical fiber; and a measuring instrument that detects the light intensity of the specimen light from the subject, wherein the optical fiber probe fixes the positions of the first optical fiber and the second optical fiber with respect to a reference position.

[0008] Furthermore, in this respect, although not limited thereto, it is preferable that the optical fiber probe comprises a ferrule that covers the periphery near the tip of the first optical fiber guide and the second optical fiber guide, and inorganic solder that fixes the ferrule to the first optical fiber guide and the second optical fiber guide.

[0009] Furthermore, in this respect, although not limited thereto, it is preferable that when the core diameter of the first optical fiber is 1, the core diameter of the second optical fiber is in the range of more than 1 and 340 or less.

[0010] In addition, in this respect, although not limited thereto, it is preferable that the tip surface of at least one of the first guiding fiber and the second guiding fiber is inclined with respect to a plane perpendicular to the respective extension axes.

[0011] In addition, in this respect, although not limited thereto, it is preferable that the fixing member has a ferrule that covers the periphery near the tip of the first optical fiber and the second optical fiber, and that the ferrule forms a reference position.

[0012] Furthermore, in this respect, although not limited thereto, it is preferable that the fixing member comprises a ferrule that covers the periphery near the tip of the first optical fiber and the second optical fiber, and a flange that is fixed to the ferrule, and that the reference position is formed by at least one of the ferrule and the flange.

[0013] Furthermore, in this respect, although not limited thereto, it is preferable that the fixing member comprises a ferrule that covers the periphery near the tip of the first optical fiber and the second optical fiber, a flange that is fixed to the ferrule, and a connector that is combined with the flange, and that the reference position is formed by at least one of the ferrule, the flange, and the connector.

[0014] In addition, in this respect, although not limited thereto, it is preferable that a light splitting means is provided in at least one of the second optical fiber and the measuring device.

[0015] Furthermore, an optical measurement method according to another aspect of the present invention is an optical measurement method that irradiates a specimen with irradiation light and detects the light intensity of the specimen light from the specimen, in which the irradiation light from a light source is guided by a first optical fiber guiding light that is fixed with respect to a reference position of a fixing member and irradiated onto the specimen, the specimen light from the specimen is guided to a measuring device by a second optical fiber guiding light that is fixed with respect to the reference position of a fixing member and has a core diameter larger than the core diameter of the first optical fiber guiding light, and the light intensity of the specimen light is detected by the measuring device. [Effects of the Invention]

[0016] As described above, the present invention can provide an optical measurement device and an optical measurement method that can be miniaturized and can measure even a minute measurement target range with high accuracy. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing an outline of a light measurement device according to an embodiment; [Figure 2]2 is a schematic enlarged view of a tip portion of the optical fiber probe according to the embodiment. FIG. [Figure 3] 3 is a schematic enlarged cross-sectional view of a fixing portion of a first optical fiber and a ferrule according to an embodiment. FIG. [Figure 4] FIG. 10 is a schematic enlarged cross-sectional view of another example of the tip portion of the optical fiber probe according to the embodiment. [Figure 5] 10 is a schematic enlarged view of another example of the tip portion of the optical fiber probe according to the embodiment. FIG. [Figure 6] FIG. 10 is a schematic enlarged cross-sectional view of another example of the tip portion of the optical fiber probe according to the embodiment. [Figure 7] 10 is a schematic diagram of another example of an optical fiber probe according to an embodiment. FIG. [Figure 8] 10 is a schematic diagram of another example of an optical fiber probe according to an embodiment. FIG. [Figure 9] 1 is a conceptual diagram of the appearance of a connector connected by an adapter according to an embodiment. FIG. [Figure 10] FIG. 1 is a schematic diagram of a light measurement device according to an embodiment. [Figure 11] FIG. 10 is a diagram showing the light receiving power of the optical fiber probe in the example. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can be embodied in many different forms and is not limited to the specific examples shown in the following embodiments.

[0019] Fig. 1 is a diagram showing an outline of an optical measurement device (hereinafter referred to as "this device") 1 according to this embodiment, and Fig. 2 is a schematic enlarged view of a tip portion of an optical fiber probe 3 in this device 1. As shown in these figures, this device irradiates a subject S with irradiation light L and detects the optical intensity of specimen light E from the subject S, and includes: a light source 2 that outputs the irradiation light L; a first optical fiber guide 31 that guides the irradiation light L to the subject S; a second optical fiber guide 32 that has a core diameter larger than the core diameter of the first optical fiber guide 31 and guides the specimen light E from the subject S to a measuring instrument 4; an optical fiber probe 3 that has a fixing member 33 that fixes the first optical fiber guide 31 and the second optical fiber guide 32; and a measuring instrument 4 that detects the optical intensity of the specimen light E from the subject S, and is characterized in that the positions of the first optical fiber guide 31 and the second optical fiber guide 32 are fixed with respect to a reference position M.

[0020] The device 1 can be miniaturized by the above configuration, and can provide an optical measurement device and an optical measurement method that can measure even a minute measurement range with high accuracy. The specific configuration and effects are as follows.

[0021] As described above, the present device 1 includes a light source 2 for irradiating light L. The configuration of the light source 2 is not limited as long as it can emit light of the wavelength required for measurement. Specifically, the present device 1 is primarily intended to analyze substances present in a specimen S, such as an organic substance, by irradiating the specimen S with irradiating light L and measuring specimen light (e.g., fluorescence) E. From this perspective, the wavelength of the light emitted by the light source 2 of the present device 1 is not limited, but is preferably light in the ultraviolet to visible region, and more preferably in the range of 100 nm to 850 nm.

[0022] As described above, the optical fiber probe 3 in this device 1 is configured to have a first optical fiber 31, a second optical fiber 32, and a fixing member 33, and the first optical fiber 31 and the second optical fiber 32 are fixed by the fixing member 33.

[0023] Furthermore, the length of the optical fiber probe 3 in the present device 1 is determined depending on the first optical fiber 31 and the second optical fiber 32, but it is sufficient if the length is long enough to allow light to propagate between the light source 2 and the subject S, and between the subject S and the measuring instrument 4, and although there are no particular limitations, it is preferable that the length be 10 m or less.

[0024] The first light guide fiber 31 of the optical fiber probe 3 is used to guide the irradiation light L to the subject S. The first light guide fiber 31 in the optical fiber probe 3 is not limited as long as it has the above-mentioned function, but includes a core 311, a clad 312 formed around the core 311, and a coating formed around the clad 312. A schematic enlarged cross-sectional view of the fixing portion of the first light guide fiber 31 and the ferrule 331 is shown in FIG.

[0025] Furthermore, the core 311 of the first guiding optical fiber 31 is provided in the clad 312 as described above, has a substantially circular cross section, and is arranged in the clad 312 so as to extend linearly.

[0026] The cross-sectional diameter of the core 311 in the first optical fiber 31 is not limited as long as it can realize the function of the device 1, but it is preferably in the range of 3 μm or more and 62.5 μm or less, for example. Specifically, in the case of single mode, it is preferable that the core diameter be 3 μm or more and 10 μm or less, and in the case of multimode, it is preferable that the core diameter be 50 μm or 62.5 μm.

[0027] Furthermore, as described above, the material of the core 311 in the first optical fiber 31 is not limited as long as it is a material that can transmit light and can cause total reflection due to the refractive index difference of the cladding 312, and examples of such materials include glass such as germanium dioxide (GeO2)-doped quartz glass and quartz glass.

[0028] Furthermore, the refractive index of the core 311 in the first optical fiber 31 is not limited as long as it is higher than the refractive index of the surrounding cladding 312 and light can be guided by total reflection within the core 311, but if the light used is assumed to be in the ultraviolet to visible range, it is preferable that the refractive index be greater than 1.46, more specifically, that the refractive index at a wavelength of 632 nm be greater than 1.46.

[0029] As described above, the cladding 312 of the first optical fiber 31 is formed around the core 311 and is used to protect the core and to utilize the difference in refractive index between the cladding 312 and the core to cause light to propagate through total reflection within the core 311. The diameter of the cross section of the cladding 312 is not limited as long as it can realize the functions of the device 1, but a certain thickness is necessary to accommodate the core 311 therein, and is preferably, for example, 80 μm or more and 200 μm or less.

[0030] Furthermore, the material of the cladding 312 in the first optical fiber 31 is not limited as long as it can realize the functions of the device 1, but examples include glass such as quartz glass and fluorine-doped glass.

[0031] Furthermore, the refractive index of the cladding 312 in the first optical fiber 31 is not limited as long as it is lower than the refractive index of the core 311 provided inside and can guide light by total reflection, but if the light used is assumed to be in the ultraviolet to visible range, it is preferable that the refractive index be 1.46 or less, more specifically, that the refractive index at a wavelength of 632 nm be 1.46 or less.

[0032] The second light guiding fiber 32 of the optical fiber probe 3 has a configuration similar to that of the first light guiding fiber 31, but has a larger core diameter than that of the first light guiding fiber 31. The first light guiding fiber 31 guides light from the light source 2 to the surface of the specimen S, while the second light guiding fiber 32 is used to guide specimen light E from the specimen S to the measuring instrument 4.

[0033] As described above, the second optical fiber 32 has basically the same configuration as the first optical fiber 31 except for its dimensions and use, so a description of the core and cladding will be omitted.

[0034] Furthermore, in the present device 1, when the core diameter of the first light guiding fiber 31 is taken as 1, the core diameter of the second light guiding fiber 32 is preferably in the range of greater than 1 and not greater than 340, more preferably greater than 10, and even more preferably greater than 100. The illumination light L irradiated onto the specimen S by the first light guiding fiber 31 is emitted as specimen light E from the specimen S, and the emitted direction of this specimen light E is wider than that of the illumination light L. Therefore, by making the core diameter of the second light guiding fiber 32 sufficiently larger than the core diameter of the first light guiding fiber 31, there is an advantage in that it is possible to take in more of this specimen light E and guide it to the measuring instrument 4.

[0035] From the viewpoint of obtaining the above-mentioned effect, the specific diameter of the core 321 of the second optical fiber 32 is preferably, for example, greater than 3 μm and less than 1000 μm, and more specifically, in the case of single mode, it is preferably in the range of greater than 3 μm and less than 10 μm, and in the case of multimode, it is preferably in the range of 30 μm or more and less than 1000 μm.

[0036] Furthermore, in the present device 1, although not limited thereto, it is preferable that the tip surface of at least one of the first optical fiber 31 and the second optical fiber 32 is inclined with respect to a plane perpendicular to the respective extension axes, and more preferably, the tip surfaces are inclined in a direction that reduces the angle between them so that they face each other.

[0037] As described above, in the present device 1, the illumination light L is emitted from the first optical fiber guide 31, and the sample light E from the sample S is guided to the measuring instrument 4 via the second optical fiber guide 32. Therefore, to achieve more efficient illumination and reception, it is preferable that the distal end surfaces of the first and second optical fibers be tilted from a direction perpendicular to their respective extension axes, more specifically, tilted toward each other. This allows the light from the first optical fiber guide 31 to be directed toward the second optical fiber guide 32, and the second optical fiber guide 32 to be directed toward the first optical fiber guide 31. In other words, the light emission direction of the first optical fiber guide 31 and the light reception direction of the second optical fiber guide 32 can be aligned, resulting in more efficient light transmission and reception. An image of this configuration is shown in FIG. 4. The tilt angle θ when tilted can be adjusted appropriately depending on the distance between the first and second optical fibers guide 31 and 32, the expected distance between them and the sample S, and other factors, but is not limited thereto. Specifically, it is preferable that the distal end surfaces of the first and second optical fibers guide 31 and 32 be independently tilted within a range of more than 0° and not more than 30°.

[0038] In this case, a flat mark surface P may be formed on the clad of at least one of the ends of the first optical fiber 31 and the second optical fiber 32, preferably on the clad of both ends. This has the advantage of making it easier to grasp the direction of inclination. An image of this case is shown in Figure 5.

[0039] Furthermore, in the present device 1, the extension axes of the first optical fiber guide 31 and the second optical fiber guide 32 may be tilted rather than parallel to each other. An image of this case is shown in FIG. 6 . In this way, similarly to the above, by tilting the light of the first optical fiber guide 31 toward the second optical fiber guide 32 and orienting the second optical fiber guide 32 toward the first optical fiber guide 31, the direction of light emitted by the first optical fiber guide 31 can be aligned with the direction in which the second optical fiber guide 32 is most likely to receive light, thereby enabling more efficient light transmission and reception. In this case, the tilt angle φ when tilted can be adjusted appropriately depending on the distance between the first optical fiber guide 31 and the second optical fiber guide 32, the expected distance between these fibers and the subject S, and other factors, but is not limited thereto. Preferably, the angle between the extension axes is greater than 0° and equal to or less than 60°.

[0040] As described above, the fixing member 33 of the optical fiber probe 3 in the present device 1 fixes the first guiding optical fiber 31 and the second guiding optical fiber 32. This makes it possible to irradiate the irradiation light L and obtain the sample light E at approximately the same position.

[0041] The optical fiber probe 3 in the present device 1 is characterized in that the positions of the first optical fiber 31 and the second optical fiber 32 are fixed with respect to the reference position M. This allows the user of the present device 1 to reliably know which side receives light, even when holding the optical fiber probe 3 in his or her hand, improving the balance between the tilt and rotational position and increasing the reproducibility of measurements. This also has the advantage of ensuring reproducibility when attaching and detaching the optical fiber probe, and maintaining high reproducibility especially when replacing the optical fiber probe with a new one. The reference position M is not limited as long as it allows the orientations of the first optical fiber 31 and the second optical fiber 32 to be determined, but it is preferable that the reference position M be fixed to the fixing member 33.

[0042] Furthermore, in this device 1, the reference position M is used to make it easier to grasp the positions of the first optical fiber 31 and the second optical fiber 32, and although not limited to this, it is preferable that this reference position M is approximately perpendicular or approximately parallel to the extension direction of the first optical fiber 31 and the second optical fiber 32, and more preferably approximately parallel or approximately perpendicular to a plane including the extension axis of the first optical fiber 31 and the extension axis of the second optical fiber 32.

[0043] Furthermore, in the present device 1, although not limited thereto, it is also preferable that the fixing member 33 includes a ferrule 331 that covers the periphery near the tip of the first light guide fiber 31 and the second light guide fiber 32, and that the reference position M is formed in the ferrule 331. An image of this case is shown in Fig. 7. In the example of this figure, the reference position M is formed in a flange 332 fixed to the ferrule 331.

[0044] Furthermore, in the present device 1, although not limited thereto, it is also preferable that the fixing member 33 includes a ferrule 331 that covers the periphery near the tip of the first light guide fiber 31 and the second light guide fiber 32, a flange 332 that is fixed to the ferrule 331, and a connector 333 that is combined with the flange 332, and that a reference position M is formed on the connector 333. For example, FIG. 8 shows an example in which the reference position M is formed on the connector 333. That is, the reference position M can be formed at various positions, such as the ferrule 331, the flange 332, or the connector 333. FIG. 9 also shows an image of the case in which the connector 333 is connected by an adapter 7. Specifically, this can be achieved by inserting and connecting a key 334 provided on the connector 333 while fitting it into a key groove 71 formed on the adapter 7.

[0045] Furthermore, in the present device 1, it is preferable that the reference position M has a flat surface, and that this flat surface has a shape that indicates a direction, more specifically, a shape that is long in one axial direction. Using a shape that can indicate a direction, such as a shape having a flat surface and an axis, has the advantage of making it easier to grasp the orientation of the light irradiation direction. In this case, it is preferable that this direction is a specific direction, specifically, approximately parallel or approximately perpendicular to the light irradiation direction (specifically, the extension direction of the first light guide fiber 31, the extension direction of the second light guide fiber 32, or a plane including both the extension axis of the first light guide fiber 31 and the extension axis of the second light guide fiber). Here, "approximately parallel" is a concept that includes perfect parallelism but also includes manufacturing errors, and an error of, for example, about ±5° is allowed. Similarly, "approximately perpendicular" is a concept that includes perfect perpendicularity but also includes an error of, for example, about ±5°. Furthermore, when a flat surface is provided, the shape of this surface is not limited to, but examples include rounded polygons such as rounded triangles and rounded rectangles, ellipses, etc., but are not limited thereto.

[0046] 3 and 4, in the present device 1, at least one of the first optical fiber 31 and the second optical fiber 32 and the fixing member 33 are preferably fixed with inorganic solder 34. In the present device 1, it is assumed that the specimen S is an organic substance, and if an organic substance is used as a bonding layer, there is a risk that fluorescence or the like based on the organic substance may be measured if the organic substance is irradiated with light from the light source 2. Therefore, using inorganic solder 34 has the effect of preventing unnecessary noise from being generated.

[0047] When inorganic solder 34 is used, the material is not limited, but it is preferable to use, for example, gold, tin, nickel, germanium, silver, lead, etc., and specific examples include combinations of gold-tin, nickel-chromium, gold-germanium, silver solder, tin-lead, etc.

[0048] Furthermore, in the present device 1, it is preferable that the tip of at least one of the first light guide fiber 31 and the second light guide fiber 32, and preferably both of them, protrude beyond the tip of the ferrule 331. This configuration has the effect of making it easier to grasp the tip positions of the first light guide fiber 31 and the second light guide fiber 32 when measuring a microscopic area with precision, and making it easier to accurately bring the tips of the first light guide fiber 31 and the second light guide fiber 32 close to the specimen S. The protruding length of the tip positions of the first light guide fiber 31 and the second light guide fiber 32 is not limited, but is preferably in the range of 0.5 mm to 2 mm, and more preferably 1.5 mm or less. The difference in protruding length between the first light guide fiber 31 and the second light guide fiber 32 is preferably 0.5 mm or less.

[0049] Furthermore, the inorganic solder 34 covers the periphery of the first optical fiber guide 31 and the second optical fiber guide 32, and in the case where the tip ends of the first optical fiber guide 31 and the second optical fiber guide 32 protrude from the tip end position of the fixing member 33 as described above, it is preferable to form a bonding layer 35 around the protruding portions of the first optical fiber guide 31 and the second optical fiber guide 32. By forming the bonding layer 35 in this portion, the inorganic solder 34 spreads in a fillet shape from the side portions of the first optical fiber guide 31 and the second optical fiber guide 32 to the tip end face of the fixing member 33, thereby making it possible to fix the first optical fiber guide 31 and the second optical fiber guide 32 to the fixing member 33, and also, when light reflected from the specimen S hits this inorganic solder 34, it can be reflected in a direction away from the first optical fiber guide 31 and the second optical fiber guide 32 (outward), which has the advantage of suppressing noise and the like that may be generated by multiple reflections.

[0050] Furthermore, when the bonding layer 35 is formed around the first optical fiber 31 and the second optical fiber 32, it is preferable that the bonding layer 35 is not formed on the entire protruding portion of the first optical fiber 31 or the second optical fiber 32, but that a portion not covered by the bonding layer 35 is formed near the tip. This has the advantage of preventing the inorganic solder 34 from adhering to the tip surfaces of the first optical fiber 31 or the second optical fiber 32. The uncovered portion (masked portion) is preferably in the range of 0.3 mm to 0.5 mm from the tip of the first optical fiber 31 or the second optical fiber 32. The tip end faces of the first optical fiber 31 and the second optical fiber 32 are basically required to be processed at right angles to the side faces of the first optical fiber 31 or the second optical fiber 32, with the accuracy being preferably in the range of 90°±1°. As a processing method, the end faces of the first optical fiber 31 and the second optical fiber 32 may be polished, or a cleave cut process may be performed using a dedicated tool.

[0051] Furthermore, when inorganic solder 34 is used to join the fixing member 33 to the first optical fiber guide 31 and the second optical fiber guide 32, it is preferable to further provide a bonding layer 35 between the inorganic solder 34 and each of the first optical fiber guide 31 and the second optical fiber guide 32. Providing the bonding layer 35 has the effect of further increasing the bonding strength between the fixing member 33, the first optical fiber guide 31, the second optical fiber guide 32, and the inorganic solder 34. The material of this bonding layer 35 is not limited, but is preferably nickel, chromium, gold, or the like, and it is important that the outermost layer is gold. In other words, sandwiching the bonding layer 35 between the inorganic solder 34 and each of the first optical fiber guide 31 and the second optical fiber guide 32 has the advantage of increasing reliability.

[0052] Furthermore, in the present device 1, it is preferable that the first guiding optical fiber 31 and the second guiding optical fiber 32 are covered with a coating material in areas other than the vicinity of their tips. The material of the coating material is not limited, but examples thereof include, but are not limited to, UV resin, polyimide resin, ETFE resin, etc. Furthermore, since the UV resin coating may be damaged, a protective tube may be attached to the outermost layer.

[0053] As described above, the measuring instrument 4 in this device 1 detects the light intensity of the specimen light E from the specimen S, and by analyzing necessary parameters such as the light intensity and spectrum, it is possible to obtain necessary information such as the substances present in the specimen S.

[0054] Furthermore, in the present device 1, the specimen light E measured by the measuring instrument 4 is preferably fluorescence emitted by the specimen S based on the irradiation light L, i.e., excitation light, irradiated onto the specimen S. "Fluorescence" refers to light emitted from the specimen S at a different wavelength after the specimen S absorbs the irradiated light and enters an excited state. However, in the present device 1, phosphorescence may also be measured because it may also be generated based on the irradiation light L. Note that the difference between the two is that fluorescence is emitted in the allowed transition from an excited singlet state to a ground singlet state, while phosphorescence is emitted in the allowed transition from an excited triplet state to a ground singlet state. Generally, phosphorescence is emitted for a longer period of time. To reiterate, the present device 1 can analyze the presence of such a substance in the specimen S by measuring this light.

[0055] Furthermore, in the present device 1, it is preferable, but not limited to, to provide a light splitting means 5 in at least one of the second optical fiber guiding optical fiber 32 and the measuring instrument 4. In the present device 1, when the illumination light L from the light source 2 is irradiated onto the specimen S, specimen light E is generated based on this. However, this specimen light E contains light of various wavelengths, and may even contain the illumination light L itself that was irradiated onto the specimen S. For this reason, it is important to provide a light splitting means 5 for splitting and acquiring the required wavelength range. Note that this light splitting means 5 may be provided not only in the second optical fiber guiding optical fiber 32, but also in the measuring instrument 4.

[0056] The light splitting means 5 is not limited as long as it has the above-mentioned function, but examples thereof include, but are not limited to, a band pass filter (BPF) and a fiber Bragg grating (FBG).

[0057] In addition, in the present device 1, it is also preferable that an optical isolator 6 is provided in the first optical fiber 31. An "optical isolator" is an optical component that transmits light traveling in one direction and blocks light traveling in the opposite direction. By providing the optical isolator 6, it is possible to prevent specimen light E and the like, which is part of the light irradiated onto the specimen S, from returning directly to the first optical fiber 31 and damaging the light source 2.

[0058] The configuration of the optical isolator 6 is not limited as long as it has the above-mentioned functions, and may be either a polarization-dependent or polarization-independent type, but if it is a polarization-dependent type, it is preferable that it includes a pair of birefringent crystals and a phase plate and a Faraday rotator disposed between the pair of birefringent crystals. This allows the light emitted from the light source 2 to be transmitted directly to the first optical fiber 31, and the light returning from the first optical fiber 31 is blocked by these elements so as not to reach the light source 2.

[0059] Furthermore, in the present device 1, the optical fiber probe 3 has an adapter 7. More specifically, it is preferable that at least one of the first optical fiber guiding fiber 31 and the second optical fiber guiding fiber 32 has an adapter 7. This has the advantage that the optical fiber probe can be attached and detached with high reproducibility, particularly when the optical fiber probe is replaced with a new one. Furthermore, in the present device 1, the first optical fiber guiding fiber 31 and the second optical fiber guiding fiber 32 are connected to the optical fiber probe 3 via connectors, and it is preferable that the optical fiber probe 3 has an adapter 7. This has the advantage that the optical fiber probe 3 can be easily attached and detached when replaced depending on the application, and that reproducibility can be maintained.

[0060] (Light measurement method) Here, an optical measurement method according to this embodiment (hereinafter referred to as "this method") will be described. This method can be realized by, but is not limited to, the above-mentioned present device 1, and specifically, it is an optical measurement method that irradiates a specimen S with irradiation light L and detects the optical intensity of specimen light E from the specimen S, in which (S1) irradiation light L from a light source is guided by a first optical fiber guiding light 31 fixed with respect to a reference position M to irradiate the specimen S, (S2) specimen light E from the specimen S is guided to a measuring instrument 4 by a second optical fiber guiding light 32 that is fixed with respect to the reference position M and has a core diameter larger than that of the first optical fiber guiding light 31, and (S3) the optical intensity of specimen light S is detected by the measuring instrument 4.

[0061] First, in this method, (S1) irradiation light L from the light source 2 is guided by the first optical fiber guiding optical fiber 31 fixed with respect to a reference position M and irradiated onto the subject S. In this case, since the reference position M is fixed, the positions of the first optical fiber guiding optical fiber 31 and the second optical fiber guiding optical fiber 32 are clear, and when the user of this device 1 places the optical fiber probe 3 with respect to the subject S, he or she can reliably know which side receives the light, etc., thereby improving the balance between the tilt and rotational position and increasing the reproducibility of the measurement.

[0062] In this method, (S2) the sample light E from the sample S is guided to the measuring device 4 through the second optical fiber 32 fixed with respect to the reference position M and having a core diameter larger than that of the first optical fiber 31.

[0063] Furthermore, in this method, (S3) the light intensity of the specimen light E is detected by the measuring instrument 4. This has the advantage that, as described above, necessary parameters such as the light intensity and spectrum can be analyzed to obtain necessary information such as substances present in the specimen S.

[0064] As described above, this device 1 makes it possible to provide an optical measurement device that can be miniaturized and can measure even a small measurement range with high accuracy, and furthermore, by using this device 1, this method can be provided. [Example]

[0065] Here, the usefulness of the present device 1 and the present method was confirmed by actually fabricating the present device 1. A specific description will be given below.

[0066] First, a reference position M was placed on a fixing member 33 prepared by scraping the surface of resin, and a first optical fiber guide 31 and a second optical fiber guide 32 were fixed thereto to form an optical fiber probe 3. In this example, one end of the first optical fiber guide 31 was connected to a light source 2 (a tunable light source TSL-210, manufactured by Santec), and one end of the second optical fiber guide 32 was connected to a measuring instrument 4 (an AQ series optical power meter, manufactured by Ando). Irradiation light L from the light source 2 was emitted from the first optical fiber guide 31, reflected by the specimen S, and then detected by the measuring instrument 4 via the second optical fiber guide 32. In this example, the specimen S was a plate-like member coated with gold, and the second optical fiber guide 32 measured specimen light E from the plate-like member coated with gold. A conceptual diagram of this case is shown in FIG. 10 . In this example, the fixing member 33 was further fixed to a rotation stage so that it could rotate (at a rotation angle θ) on a plane perpendicular to the ground surface.

[0067] In this example, the size of the first light guide fiber 31 was fixed, while a plurality of sizes of the second light guide fiber 32 were prepared, thereby producing a total of four types of optical fiber probes 3. More specifically, an optical fiber having a core diameter of 8 μm and a cladding diameter of 125 μm was used as the first light guide fiber 31, and any one of (A) an optical fiber having a core diameter of 50 μm and a cladding diameter of 125 μm (hereinafter referred to as "second light guide fiber A"), (B) an optical fiber having a core diameter of 105 μm and a cladding diameter of 125 μm (hereinafter referred to as "second light guide fiber B"), (C) an optical fiber having a core diameter of 200 μm and a cladding diameter of 220 μm (hereinafter referred to as "second light guide fiber C"), or (D) an optical fiber having a core diameter of 400 μm and a cladding diameter of 440 μm (hereinafter referred to as "second light guide fiber D") was used as the second light guide fiber 32.

[0068] 11 shows the results of the power of light received by the second optical fiber 32 (received light power) when the wavelength of light from the light source 2 is 1550 nm and the output is 3 mW. As shown in this figure, in the optical fiber probe 3 using the second optical fiber A, it was confirmed that the intensity increases as the core diameter increases from second optical fiber A to second optical fiber B, second optical fiber C, and second optical fiber D. In particular, there is dependency on the rotation angle θ, and in this embodiment, since the reference position M serving as a marker was placed, it was confirmed that the reproducibility of this received light power could be maintained at a high level.

[0069] As described above, this example confirmed the usefulness of the present device and method. [Industrial Applicability]

[0070] The present invention has industrial applicability as a light measurement device and a light measurement method. [Explanation of symbols]

[0071] 1...Light measuring device 2…Light source 3...Optical fiber probe 31...First guide fiber 311...Core 312...Clad 32...Second optical fiber 321...Core 322...Clad 33...Fixing member 331...Ferrule 332...Flange 333...Connector 334...Key 34...Inorganic solder 35...Joining layer 4…Measuring instrument 5...Light splitting means 6...Optical isolator 7...Adapter 71...Keyway S…Subject L…Irradiation light E...Specimen light M…Reference position

Claims

1. A light measurement device that irradiates a test object with irradiation light and detects the light intensity of the test object light from the test object, a light source that outputs the irradiation light; a first optical fiber guiding the irradiation light to the subject; a second optical fiber guiding the specimen light from the specimen, the second optical fiber guiding the specimen light having a core diameter larger than that of the first optical fiber guiding the specimen light; an optical fiber probe having a fixing member for fixing the first optical fiber and the second optical fiber; a measuring instrument for detecting the light intensity of the specimen light from the specimen, The optical fiber probe has a light measurement device in which the positions of the first optical fiber guide and the second optical fiber guide are fixed with respect to a reference position.

2. The optical fiber probe includes:

2. The optical measurement device according to claim 1, further comprising: a ferrule that covers the periphery of the first optical fiber and the second optical fiber near their tips; and inorganic solder that fixes the ferrule to the first optical fiber and the second optical fiber.

3. 2. The optical measurement device according to claim 1, wherein the core diameter of the second optical fiber is in the range of greater than 1 and not more than 340, where the core diameter of the first optical fiber is 1.

4. 2. The optical measurement device according to claim 1, wherein the tip end surface of at least one of the first optical fiber guide and the second optical fiber guide is inclined with respect to a plane perpendicular to the extension axis of the first optical fiber guide and the second optical fiber guide.

5. The fixing member is a ferrule covering the vicinity of the tip of the first optical fiber and the second optical fiber; 2. The optical measurement device according to claim 1, wherein the reference position is formed by the ferrule.

6. The fixing member is 2. The optical measurement device according to claim 1, further comprising: a ferrule that covers the periphery of the first optical fiber and the second optical fiber near their tips; and a flange that is fixed to the ferrule, and the reference position is formed by at least one of the ferrule and the flange.

7. The fixing member is a ferrule that covers the periphery of the vicinity of the tip of the first optical fiber and the second optical fiber; a flange that is fixed to the ferrule; and a connector that is combined with the flange, 2. The optical measurement device according to claim 1, wherein the reference position is formed by the ferrule and at least one of the flange and the connector.

8. 2. The optical measurement device according to claim 1, wherein a light splitting means is provided in at least one of said second optical fiber and said measuring device.

9. 1. A light measurement method for irradiating a test object with irradiation light and detecting the light intensity of the test light from the test object, comprising: The irradiation light from the light source is guided by a first optical fiber guide fixed with respect to a reference position of one fixing member, and is irradiated onto the subject; the specimen light from the specimen is guided to a measuring device by a second optical fiber guide that is fixed with respect to the reference position of the one fixing member and has a core diameter larger than the core diameter of the first optical fiber guide; an optical measurement method in which the light intensity of the sample light is detected by the measuring device;

Images