JPH08261921A - Manufacture for optical fiber probe - Google Patents

Abstract

PURPOSE: To manufacture an optical fiber probe allowing a pigment to be stuck to only the sharpened tip section of optical fiber. CONSTITUTION: A solvent 9 mixed with a functional material changed with the optical characteristic in response to the ambient environment is filled into a capillary tube 6 from the opposite side to an opening section 8. The solvent filled into the capillary tube 6 is shifted near to the opening section 8 at the tip of the capillary tube 6 along a glass tube 6a and a glass rod 7 via the capillary phenomenon. Tips of a sharp section 4 and the capillary tube 6 are approached together, a flat section 5 at the tip of the sharp section 4 is brought into contact with the solvent 9 shifted to the opening section 8 at the tip of the capillary tube 6, and a detection section containing a functional material is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an optical fiber probe in which a tip of a protruding portion of a core protruding from a clad is sharpened, and more particularly, an optical fiber sensor for detecting an environment around the tip of the optical fiber probe. The present invention relates to a method for manufacturing an optical fiber probe used as a.

[0002]

2. Description of the Related Art Conventionally, at one end of an optical fiber composed of a core and a clad, the core is projected from the clad, and the projected core is formed into a sharpened pointed end, and a sharpened point is formed at the tip of the sharpened part. 2. Description of the Related Art There is known a so-called super chip, which is an optical fiber sensor in which a detection part is formed by adhering a dye, a reagent and the like.

In such an optical fiber sensor, the emission spectrum or the absorption spectrum changes when the environment around the detector, such as pH, a certain functional substance to be detected is detected. Therefore, for example, the detection light is made incident on the optical fiber from the other end of the sharpened portion, or the detection light is made incident on the sharpened portion from the outside, and the spectrum of the detected light detected at the tip of the probe or the other end of the sharpened portion is detected. By doing so, the pH, the functional substance to be detected, and the like are measured. In such an optical fiber sensor, the detection unit is made smaller to improve the spatial resolution of detection as compared with the conventional electric sensor, and the pH in a minute region, the functional substance to be detected, etc. are measured. be able to.

In order to manufacture such an optical fiber sensor, one end of the optical fiber is etched to form a sharpened portion 32 in which the end of the optical fiber 31 is tapered as shown in FIG. Then, the solvent 33 mixed with a dye or the like is placed in a container, and the tip of the sharpened portion 32 is brought into contact with the solvent 33 to form a detection portion in which the solvent is attached to the tip of the sharpened portion 32.

[0005]

However, when the tip of the sharpened portion 32 is brought into contact with the solvent 33 in the container as described above, it is difficult to accurately control the position of the optical fiber 31. As shown in FIG. 12, the sharpened portion 3
The solvent also adheres to other than the tip of 2, and the detection unit 34 becomes large. In particular, when the tip of the sharpened portion 32 becomes smaller than the wavelength of light, it becomes impossible to detect the position of the tip of the sharpened portion 32 by an optical method, and the dye is attached only to the tip of the sharpened portion 32 so that the detecting portion is formed. It becomes difficult to form 34.

Since the spatial resolution of the optical fiber sensor depends on the size of the detecting portion 34, as described above, when the solvent adheres to the tip portion of the sharpened portion 32 and the detecting portion 34 becomes large, the detection space becomes large. There is a problem of reduced resolution.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing an optical fiber probe in which a dye can be attached only to a minute tip.

[0008]

A method of manufacturing an optical fiber probe according to the present invention comprises a tip having an end portion of an optical fiber comprising a core and a clad covering the periphery of the core, and a tip having a flat portion having a wavelength equal to or shorter than a wavelength of detection light. A tapered sharp tip is formed.
Then, a solvent in which a functional substance whose optical characteristics change according to the surrounding environment is mixed is injected into a capillary tube made of a cored glass tube having an opening having an inner diameter larger than that of a flat portion at the tip of the sharpened portion. Further, the flat part is brought into contact with the solvent at the tip of the capillary tube to form a detection part having a functional substance attached to the surface of the flat part.

Further, in the method for manufacturing an optical fiber probe according to the present invention, the functional substance or solvent has a color, and when forming the detection part, the flat part is brought close to the tip of the capillary tube, and the flat part is the capillary tube. After confirming the color of the functional substance or solvent exposed from the tip of the capillary when contacting the solvent at the tip, the sharpened part and the tip of the capillary are separated from each other.

[0010]

In the method of manufacturing an optical fiber probe according to the present invention, first, at the tip of an optical fiber composed of a core and a clad covering the periphery of the core, a tapered tip having a flat portion at a wavelength equal to or shorter than the wavelength of the detection light is formed. Form a sharp point.

Next, a capillary tube made of a cored glass tube having an opening with an inner diameter larger than that of the flat portion at the tip of the sharpened tip is mixed with a solvent in which a functional substance whose optical characteristics change according to the surrounding environment is mixed. inject. As a result, the injected solvent is transferred to the tip of the capillary due to the capillary phenomenon.

Then, the flat portion is brought into contact with the solvent at the tip of the capillary tube. Here, when the functional substance or the solvent has a color, these colors can be confirmed when the functional substance or the solvent is exposed from the tip of the capillary when the flat portion comes into contact with the solvent at the tip of the capillary. Therefore, by confirming the color of the functional substance or the solvent exposed from the tip of the capillary, it can be confirmed that the solvent is in contact with the flat portion.
Then, after confirming that the solvent has contacted the flat portion, the sharpened portion and the tip of the capillary are separated.

As a result, the tip of the optical fiber has a pointed sharp tip having a flat portion having a wavelength equal to or shorter than the wavelength of the detection light at the tip, and the optical characteristics change on the surface of the flat portion according to the surrounding environment. An optical fiber probe having a detection part to which a functional substance is attached is formed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a method for manufacturing an optical fiber probe according to the present invention will be described below with reference to the drawings.

In the method of manufacturing an optical fiber probe according to this embodiment, for example, as shown in FIG. 1, a sharpening step S for etching one end of the optical fiber to sharpen the tip of the core.
1, an injection step S2 of injecting a solvent in which a functional material whose optical characteristics change according to the surrounding environment is injected into the capillary tube, and the tip of the optical fiber is brought into contact with the solvent at the tip of the capillary tube to perform the above-mentioned function. And an attaching step S3 for attaching a volatile substance.

The above steps will be described in detail below.

In the sharpening step S1, one end of an optical fiber comprising a core made of quartz SiO ₂ to which germanium oxide GeO ₂ is added and a clad made of quartz SiO ₂ or the like is formed from an aqueous solution of ammonium fluoride, hydrofluoric acid and water. Etching with a buffered hydrofluoric acid solution.

[0018] performing such _{etching, SiO 2: SiO 2 + 6HF} → H 2 SiF 6 + 2H 2 O H 2 SiF 6 + 2NH 3 → (NH 4) 2 SiF 6 GeO 2: GeO 2 + 6HF → H 2 The cladding 2 and the core 1 are etched by a chemical reaction of GeF ₆ + 2H ₂ OH ₂ GeF ₆ + 2NH ₃ → (NH ₄ ) ₂ GeF ₆ .

There is a difference in dissolution rate between the core made of quartz to which germanium oxide GeO ₂ is added and the clad made of quartz in the buffer hydrofluoric acid solution. Where concentration 4
0% by weight ammonium fluoride aqueous solution and concentration 50% by weight
If the volume ratio of hydrofluoric acid to water is X: 1: Y (Y = arbitrary), the difference in dissolution rate between the core and the clad has a strong correlation with the volume ratio X of ammonium fluoride NH ₄ F.

Therefore, although there is some variation depending on the temperature of the liquid, the etching rates of the core and the clad are almost equal when X = 1.5 to 1.7, and X <1.5 (or X <1.
In 7), the etching rate of the core is relatively high, X> 1.5
(Or X> 1.7), the melting rate of the clad is relatively high. Therefore, by using this buffered hydrofluoric acid solution as an etching solution, the core and the clad can be selectively etched.

In this sharpening step S1, an optical fiber having a core to which germanium oxide GeO ₂ is added at about 25 mol% has a volume ratio X of ammonium fluoride NH ₄ F of about 10 and a volume ratio Y of water of 1. Etching with a buffered hydrofluoric acid solution at a temperature of 25 ° C. for about 60 minutes. This optical fiber is made of germanium oxide Ge added to the core.
The density distribution is provided so that the density of O ₂ is high in the central part of the core and low in the outer peripheral part of the core.

When such etching is performed, the volume ratio X of ammonium fluoride NH ₄ F in the etching solution is 10
Since the etching rate of the clad is higher than the etching rate of the core, the clad is etched first to form a protrusion in which the core protrudes from the tip of the clad.

When the etching is completed in about 60 minutes, the tip of the conically sharpened core is not completely sharpened, and the core 2 is formed at one end of the optical fiber 1 as shown in FIG. The flat portion 5 remains at the tip of the sharpened portion 4 protruding from the clad 3 in a tapered shape. Specifically, the clad 3 diameter d ₀ is about 123 μm, and the core 2 diameter d _c is 3.4 μm.
When the optical fiber 1 of about m is used, the diameter d ₁ of the flat portion 5 is about 300 nm, as shown in FIG. As a result, 400 to 7 which is the wavelength of the detection light, for example, visible light.
A flat portion 5 having a diameter of 50 μm or less is formed.

Next, in the injection step S2, a solvent in which a functional substance whose optical characteristics change according to the surrounding environment is mixed is injected into the capillary tube.

The capillary tube used in this injection step is, for example, as shown in FIG. 4, a cored glass tube in which a glass rod 7 is attached to the inner wall of a glass tube 6a is stretched in a heated state,
The inner diameter of the opening 8 at the tip is made smaller until the inner diameter becomes slightly larger than the flat portion 5 at the tip of the sharpened portion 4. In this case, the inner diameter d ₃ of the opening 8 is 600 nm, which is about twice the diameter d ₁ of the flat portion 5.

In this injection step, ethanol is used as a solvent, and 6.3 × 10 ⁻ Rhodamine 6G (Rhodamine 6G), which is a laser dye that emits light according to the intensity of ambient light, is used as a functional substance in the ethanol. mixed at a concentration of about ² M. Then, ethanol mixed with this rhodamine 6G is injected into the capillary tube 6 from the opposite side of the opening 8 using a syringe.

As a result, for example, as shown in FIG. 5, the ethanol 9 injected into the capillary tube 6 is transferred to the vicinity of the opening 8 at the tip of the capillary tube 6 along the glass tube 6a and the glass rod 7 by the capillary phenomenon.

Next, in the adhering step S3, as shown in FIG. 5, the tip portion 4 and the tip of the capillary tube 6 are brought close to each other, and the flat portion 5 at the tip of the tip portion 4 is transferred to the opening 8 at the tip of the capillary tube 6. The ethanol 9 thus prepared is contacted.

Specifically, in this attaching step S3, as shown in FIG.
Using the micromanipulator shown in, the capillary tube 6 in which ethanol 9 is injected as described above is moved to
The tip of is brought close to the sharpened portion 4 of the optical fiber 1 fixed to the fixed portion 10.

This micromanipulator has a drive system 12 for moving the capillary tube 6 in response to a user's operation of the operating section 11, and a light source 13 for irradiating the sharpened portion 4 of the optical fiber 1 and the capillary tube 6 as an object with irradiation light. And an optical system 15 that forms an image of light incident through a subject on the imaging system 14,
The display unit 16 displays an image based on the image pickup output from the image pickup system 14.

Then, the user sees the images of the sharpened portion 4 and the capillary tube 6 displayed on the display unit 16 while looking at the operation unit 11
Is operated to move the capillary tube 6 to bring the flat portion 5 at the tip of the sharpened portion 4 into contact with the ethanol 9 transferred to the opening 8 at the tip of the capillary tube 6. Here, since the rhodamine 6G mixed in the ethanol 9 is red, when the flat portion 5 comes into contact with the ethanol 9 in the opening 8 and the ethanol 9 is exposed from the opening 8, the exposed ethanol 9 is imaged. System 14
The image of the ethanol 9 exposed by the image pickup is displayed on the display unit 16 according to the image pickup output.

The user can confirm that the flat portion 5 is in contact with the ethanol 9 in the opening 8 by looking at the image of the exposed ethanol 9. When the user confirms that the flat portion 5 and the ethanol 9 in the opening 8 are in contact with each other, the user operates the operation portion 11 to separate the capillary tube 6 from the sharpened portion 4. That is, the user can separate the sharpened portion 4 and the tip of the capillary tube 6 after confirming that the ethanol 9 has come into contact with the flat portion 5, and the ethanol can be reliably attached to the flat portion 5.

As a result, ethanol mixed with Rhodamine 6G is attached to the surface of the flat portion 5, and as shown in FIG. 7, the optical fiber probe 20 having the detection portion 18 formed on the surface of the flat portion 5 is formed. .

The diameter of the detecting portion 18 thus formed is such that ethanol is attached only to the flat portion 5,
As shown in FIG. 8A, the diameter is about the diameter of the flat portion 5.
That is, when the flat portion 5 has a diameter of about 300 nm as described above, the diameter of the detection portion 18 is about 300 nm as shown in FIG.

In this optical fiber probe manufacturing method,
As described above, the detection unit 18 is formed by adhering the solvent mixed with the functional substance such as a dye only to the surface of the flat portion 5 having the wavelength of the detection light or less at the tip of the sharpened portion 4 of the optical fiber 1. You can

Further, in the optical fiber probe 20 formed as described above, when light is incident on the detector 18, the rhodamine 6G of the detector 18 emits red light in response to the incident light. The diameter of the detection unit 18 is about 300 nm and 400 to 7
Since the wavelength is smaller than the wavelength of visible light of about 50 μm, the optical fiber probe 20 can detect light emission in a minute region equal to or shorter than the wavelength of visible light. As a result, the emission intensity distribution of the object to be detected can be accurately measured.

In this method of manufacturing an optical fiber probe,
It is possible to form the detection unit 18 by adhering a solvent mixed with a functional substance such as a dye whose optical characteristics change according to the surrounding environment only to the tip of the flat portion 5 having a size equal to or smaller than the wavelength of the detection light. it can. Optical fiber probe 2 formed in this way
In the case of 0, the size of the detection unit 18 is extremely small, which is equal to or less than the wavelength of the detection light, so that the spatial resolution of detection can be improved.

As the functional substance mixed with ethanol and attached to the flat portion 5, other than the above-mentioned laser dye Rhodamine 6G, the pH around the detecting portion 18, the functional substance to be detected, and the like are used. It is possible to use a functional substance or the like whose optical characteristics such as absorptance and refractive index change.

For example, by using, as the functional substance, a substance whose light emission property changes according to the ion concentration of the ions to be detected, the ion concentration around the detecting portion 18 can be detected. Specifically, the concentration of calcium ions can be detected by using, as the functional substance, so-called Fluoro-3 (Fluo-3), calcium green, Rhod-2, Fura-Red or the like. Moreover, as functional substances, so-called methyl red (Methyl Red) and bromothymol blue (Bromothymol
Blue), phenolphthalein (Phenolphthalein) and the like can be used to detect the concentration of hydrogen ions.

As the functional substance, 1-anilinonaphthalene-8-sulfonic acid (ANS: 1-anilino na) whose optical characteristics change depending on the polarity of the substance around the detecting portion 18
phthalein 8-sulfonic acid), N-methyl-2-anilinonaphthalene-6-sulfonic acid (MANS: N-methyl)
2-anilino naphthalein 6-sulfonic acid), 2-p
-Toluidinylnaphthalene-6-sulfonic acid (TNS:
2-para-toluidinyl naphthalein 6-sulfonic acid) or the like can be used to detect the polarity of the substance around the detection unit 18.

The membrane potential can be measured by using a so-called cyanine dye, oxole dye or the like as the functional substance. Further, by using acridine orange, 9-amino acridine, or the like as the functional substance, it can be used to investigate the macroscopic structure of DNA.

The temperature or pressure can be detected by using, as the functional substance, so-called spiropyranine, fluorane, or the like, whose optical characteristics change depending on the temperature or pressure around the detecting portion 18. Also,
So-called photochemical hole-burning materials such as quinizarin and porphyrin dyes are used as functional materials, and by utilizing their nonlinearity and resonance effect, they are applied to basic experiments of optical memory by utilizing the light amplification effect. be able to. In addition, as a functional substance, N- (4-
Nitrophenyl)-(L) -proninol (N- (4-nitro
phenyl) (L) pronynole: NPP), 4 (dimethylamino) -4-nitrostilbene (4 (dimethylamino) 4-nit
By using a non-linear optical material such as rostilbene (DANS), a non-linear photodetection characteristic can be obtained.

As the solvent for mixing the functional substance as described above, other than the above-mentioned ethanol, other organic solvents such as alcohols and ketones may be used, or a low temperature can be obtained by the sol-gel method. You may use the solvent which becomes an amorphous state at.

When such a solvent is used, the above-mentioned functional substance is mixed with the solvent in the above-mentioned injecting step and injected into the capillary tube 6, and the solvent is attached to the flat portion 5 in the attaching step.

For example, tetramethoxysilane (hereinafter, TM
When a solution based on so-called methyl silicate nSi (OCH ₃ ) ₄ (OS: Tetra metoxi siran) is hydrolyzed and polymerized, hydrolysis: nSi (OCH ₃ ) ₄ + 4nH ₂ O → nSi (OH) ₄ + 4nCH ₃ OH polymerization reaction: Si (OH) ₄ + Si (OH) ₄ → (OH) ₃ Si—O—Si (OH) ₃ + H ₂ O (OH) ₃ Si—O—Si (OH) ₃ + Si (OH) _The reaction of ₄ → (OH) ₃ Si—O—Si (OH) ₂ —O—Si (OH) ₃ + H ₂ O proceeds to increase the viscosity of the solution. At this time,
The volume of the solvent adhering to the flat portion 5 decreases and solidifies to form a transparent gel.

As a result, an amorphous layer containing a functional substance can be formed on the surface of the flat portion 5 at a lower temperature than when glass is processed at a high temperature. It is possible to form the detection unit 18 having a functional substance that is destroyed. Further, since the functional substance is mixed in the amorphous layer, the peel strength of the detection unit 18 can be improved.

When such a solvent is used, semiconductor fine particles such as cadmium selenium CdS _x Se _1-x , cuprous chloride CuCl, cuprous bromide CuBr can be used as the functional substance. When these functional substances are used, the refractive index and the like change according to the environment around the detection unit 18.

By forming the detection section 18 using these functional substances, the optical characteristics of the detection section 18 change according to the environment around the detection section 18. Since the size of the detection unit 18 is equal to or less than the wavelength of the detection light such as visible light as described above, the change in the optical characteristics of the detection unit 18 is detected on the opposite side of the detection unit 18 of the optical fiber 1. It is possible to measure the environment in a region below the wavelength of the detection light such as visible light.

As a result, it becomes possible to measure the environment in a region that cannot be measured by an optical method, and the spatial resolution of measurement can be improved.

By the way, the above-mentioned optical fiber probe 20.
Since the rhodamine 6G of the detection unit 18 absorbs the light around the detection unit 18 and emits red light, it can be used as an optical sensor for detecting the light incident on the detection unit 18.

Further, such an optical fiber probe 20
Since the diameter of the detection unit 18 is smaller than the wavelength of the detection light such as visible light, can be used to detect so-called evanescent light existing in the region of the wavelength of the light on the material surface or less.

When performing, a so-called photon scanning tunneling microscope is used to irradiate the back surface of the sample surface 19 with laser light, and the distance between the tip of the detection section 18 and the sample surface 19 is set to about the wavelength of the laser light or less. The detection unit 18 scans the sample surface 19.

When laser light is incident on the back surface of the sample surface 19 at a total reflection angle, so-called evanescent light is generated from the sample surface in a region of about the wavelength of the laser light or less. Since the intensity of the evanescent light decreases as the distance from the sample surface 19 increases, the evanescent light having the intensity corresponding to the distance from the sample surface 19 enters the detection unit 18.

The rhodamine 6G of the detector 18 absorbs the incident evanescent light and emits red light in accordance with the intensity of the absorbed evanescent light. This luminescence is generated by the sharp tip 4
It is incident on the core 2 via. Accordingly, if the intensity of the light incident on the core 2 is detected on the side opposite to the sharpened portion 4, the distance between the detection portion 18 and the sample surface 19 can be detected. Then, the shape of the sample surface 19 can be measured by obtaining the light intensity distribution according to the scanning of the detection unit 19.

Further, in the optical fiber probe 20 used for detecting the evanescent light as described above,
When the sample surface is scanned by the sharpened portion 4, the cladding 3
There is a possibility that the periphery of the tip of the sample collides with the sample surface 19 and damages the sample surface 19 or the optical fiber probe 20 itself.

Therefore, prior to the etching in the sharpening step S1 described above, one end of the optical fiber 1 is etched with hydrofluoric acid to reduce the diameter of the cladding 3 to form a small diameter portion of a diameter d ₃ and then sharpen it. The etching in the conversion step S1 may be performed.

In this case, as shown in FIG. 10, a small diameter portion 25 having a thin clad can be formed at the base end of the above-mentioned sharpened portion 4. This can prevent the periphery of the tip of the clad 3 from colliding with the sample surface 19.

In the above embodiment, the case where one end of the optical fiber is etched to form the sharpened portion has been described, but it is possible to form the sharpened portion having a flat portion equal to or shorter than the wavelength of the detection light at the tip. If possible, the optical fiber may be stretched while being heated to form the sharpened portion. Further, in the above-described embodiment, the visible light is assumed as the detection light, and the flat portion 5
The diameter of the flat portion 5 is not more than the wavelength of ultraviolet rays when ultraviolet rays or the like is used as the detection light, and the diameter of the flat portion 5 is within the range not departing from the technical idea of the present invention. Various changes are possible.

[0059]

According to the present invention, at the tip of an optical fiber composed of a core and a clad covering the periphery of the core, a tip-shaped tapered tip having a flat portion equal to or shorter than the wavelength of the detection light is formed at the tip. Inject a solvent mixed with a functional substance whose optical characteristics change according to the surrounding environment into a capillary tube consisting of a cored glass tube having an opening with an inner diameter larger than the flat part of the flat part of the The solvent can be attached only to the tip of the sharpened portion by bringing the solvent into contact with the solvent at the tip. As a result, an optical fiber probe with improved spatial resolution for detection can be created.

Further, according to the present invention, since the color of the functional substance or the solvent exposed from the tip of the capillary can be confirmed when the flat portion comes into contact with the solvent at the tip of the capillary, the solvent comes into contact with the flat portion. After confirming that, the sharpened portion and the tip of the capillary can be separated. Therefore, the solvent can be surely attached to the flat portion.

[Brief description of drawings]

FIG. 1 is a process drawing showing a process of a method for manufacturing an optical fiber probe to which the present invention is applied.

FIG. 2 is a cross-sectional view showing a structure of an optical fiber formed by a sharpening step of the method for manufacturing an optical fiber probe.

FIG. 3 is a side view showing the shape of a protrusion at the tip of the optical fiber.

FIG. 4 is a perspective view showing the shape of the tip of a capillary tube used in the injection step of the method for manufacturing an optical fiber probe.

FIG. 5 is a diagram for explaining an attaching step of the method for manufacturing the optical fiber probe.

FIG. 6 is a diagram for explaining the attaching step.

FIG. 7 is a cross-sectional view showing the structure of an optical fiber probe formed by the method for manufacturing an optical fiber probe.

FIG. 8 is a side view showing a structure of a sharpened portion of the optical fiber probe.

FIG. 9 is a diagram for explaining the measurement of the shape of the sample surface using the optical fiber probe.

FIG. 10 is a cross-sectional view showing the structure of another optical fiber probe formed by the method for manufacturing an optical fiber probe.

FIG. 11 is a diagram for explaining a step of adhering a solvent to the tip of an optical fiber in the conventional method for manufacturing an optical fiber probe.

FIG. 12 is a cross-sectional view showing a structure of an optical fiber probe formed by the conventional method for manufacturing an optical fiber probe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Core 3 Clad 4 Pointed part 5 Flat part 6 Capillary tube 8 Opening part 9 Solvent 18 Detection part

Claims (2)

[Claims] 1. A tapered sharpened portion having a flat portion having a wavelength equal to or shorter than a wavelength of detection light is formed at the tip of an optical fiber composed of a core and a clad covering the core, and the tip of the sharpened portion is formed. A capillary tube made of a glass tube with a core having an opening with an inner diameter larger than that of the flat portion is injected into a solvent mixed with a functional substance whose optical characteristics change according to the surrounding environment, and the flat portion is attached to the end of the capillary tube. A method for manufacturing an optical fiber probe, which comprises contacting the solvent with the above-mentioned solvent to form a detection part having the above-mentioned functional substance attached to the surface of the flat part. 2. The functional substance or solvent has a color, and when forming the detection part, the flat part is brought close to the tip of the capillary tube, and the flat part comes into contact with the solvent at the tip of the capillary tube. The method for manufacturing an optical fiber probe according to claim 1, wherein after confirming the color of the functional substance or solvent exposed from the tip of the capillary tube, the sharpened portion and the tip of the capillary tube are separated from each other.