JP2001013363A - Optical fiber terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the peeling of an adhesive layer of an adhesive, to prevent the pull-off of a jacket from a pipe and to prevent the disconnection of a bare fiber by adhering the pipe and a capillary and the bare fiber and the jacket in such a manner that the adhesive is packet into a clearance formed by the pipe and the capillary. SOLUTION: The optical fiber terminal is formed with the clearance 6 by the difference in level of the pipe 1 and the end face of the capillary 2. The adhesive 5, therefore, flows into the clearance 6 and cures like a flange. The clearance 6 suffices with the clearance to the extent of allowing the intrusion of the adhesive 5. Namely, the adhesive 5 forms the flange by flowing into the clearance 6 and, therefore, the adhesive 5 cured like the flange at the difference in level of the pipe 1 plays the role of hooking, thereby making the peeling of the adhesive 5 from the pipe 1 difficult. Also, the peeling of the adhesive 5 from the jacket 4 is made difficult by reforming of the surface of the jacket 4, such as a treatment to roughen the surface. Further, the removal of the jacket 4 from the pipe 1 does not occur any more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical communication system,
The present invention relates to an optical connector used for a measurement system and the like and an optical fiber terminal of an optical semiconductor module.

[0002]

2. Description of the Related Art FIG. 13 is a cross-sectional view of a conventional optical fiber terminal disclosed in Japanese Utility Model Laid-Open No. 1-62513, and FIG. FIG. 3 is a view showing a state in which the adhesive layer of FIG.
In the drawing, reference numeral 61 denotes a pipe having a flange on the outside and formed in two steps with a large inside diameter and a small inside diameter; 62, a capillary press-fitted so as to be in close contact with a step portion inside the pipe 61;
63 is a bare fiber, 64 is a jacket fixed so as to cover a part of the bare fiber 63, and 65 is an adhesive for fixing the bare fiber 63 and the jacket 64 to the pipe 61 and the capillary 62. Generally, jacket 64
Is composed of a primary coating portion of an ultraviolet-curable acrylate resin or a silicone resin and a secondary coating portion of nylon or a flame-retardant polyester resin.
The structure composed of the jacket 3 and the jacket 64 is called an optical fiber. The adhesive 65 is an epoxy-based adhesive. Further, an optical fiber end having a flange on a pipe like the conventional optical fiber end shown in FIG. 13 is used for an optical connector plug in combination with parts such as a spring and a nut.

In the conventional optical fiber terminal shown in FIG. 13, the inner diameter of the pipe 61 and the outer diameter of the jacket 64 are uniform and have almost no irregularities, as shown in FIG. Therefore, when thermal stress due to temperature change is applied to the optical fiber terminal, the pipe 61 or the jacket 64
The adhesive 65 may peel off at the contact surface with the adhesive. Also,
Since the material of the jacket 64 is a resin, the jacket 64 may contract due to aging or temperature change. If the adhesive is peeled off, the adhesive force between the bare fiber 63 and the jacket 64 is generally weak, and when the jacket shrinks in a state where the adhesive is peeled off, as shown in FIG.
A hollow portion is formed inside the optical fiber terminal through the jacket 64 from 1 and the bare fiber 63 is exposed in the hollow portion. If any stress such as twisting or pulling is applied to the jacket 64 or the bare fiber 63 in such a state, the stress is concentrated on the bare fiber in the hollow portion, and the bare fiber is broken at this portion.

[0004]

As shown in FIG. 14, the conventional optical fiber terminal constructed as described above has an adhesive 65 at the contact surface with the pipe 61 or the jacket 64.
Is peeled off, and when the shacket 64 shrinks due to aging or temperature change, the jacket 64 comes off the pipe 61 to form a hollow portion inside the optical fiber terminal, and the bare fiber 63 is exposed to the hollow portion. Therefore, there is a problem that even if an external stress is applied to the jacket 64 even a little, stress is applied to the exposed portion of the bare fiber 63 and the bare fiber 63 is disconnected at the hollow portion.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and when forming an optical fiber terminal, even if a thermal stress due to a temperature change is applied to the optical fiber terminal, an adhesive layer of an adhesive is used. Does not peel off, and even if the adhesive layer peels off, the jacket does not come off the pipe,
It is an object of the present invention to obtain a highly reliable optical fiber terminal that does not cause a break in a bare fiber.

[0006]

According to a first aspect of the present invention, there is provided an optical fiber terminal in which the inside of a pipe is formed in two steps with large and small inside diameters, and a gap is formed between a step surface of the pipe and an end face of the capillary. And a pipe, a capillary, a bare fiber, and a jacket are bonded so that the gap is filled with an adhesive.

An optical fiber terminal according to a second aspect of the present invention is configured such that a groove is provided on an outer periphery of a jacket, and a pipe, a capillary, a bare fiber, and a jacket are bonded so that the groove is filled with an adhesive. is there.

In the optical fiber terminal according to the third aspect of the present invention, the inside of the pipe is formed in two steps with large and small inner diameters, and the capillary is arranged so as to form a gap between the step surface of the pipe and the end face of the capillary. A groove is provided on the outer periphery of the jacket, and the pipe, the capillary, the bare fiber, and the jacket are bonded so that the gap and the groove are filled with an adhesive.

An optical fiber terminal according to a fourth aspect of the present invention is provided with a hole penetrating from the outside to the inside of the pipe and a groove provided on the outer periphery of the jacket so that the hole and the groove are filled with an adhesive. It is configured to bond a pipe, a capillary, a bare fiber, and a jacket.

An optical fiber terminal according to a fifth aspect of the present invention is characterized in that a projection is provided inside the pipe, a groove is provided on the outer periphery of the jacket, and the pipe, the capillary, and the bare fiber are bonded so that the groove is filled with an adhesive. It is configured to adhere to a jacket.

According to a sixth aspect of the present invention, in the optical fiber terminal, a taper is provided on an end face of the capillary to form a gap between the tapered surface and a step surface of the pipe, and a groove is provided on the outer periphery of a jacket. The pipe, the capillary, the bare fiber, and the jacket are bonded so that the groove is filled with an adhesive.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a sectional view of an optical fiber terminal showing the first embodiment of the present invention, and FIG. 2 is a sectional view showing a pipe and a capillary of the optical fiber terminal of the present invention shown in FIG. In the drawing, reference numeral 1 denotes a pipe having a flange on the outside and formed in two steps with large and small inside diameters, 2 denotes a capillary press-fitted into the pipe 1, 3 denotes a bare fiber, and 4 denotes a part of the bare fiber 3. The jacket 5 fixed in this state is an adhesive for fixing the bare fiber 3 and the jacket 4 to the pipe 1 and the capillary 2, and 6 is a gap formed between the step surface of the pipe 1 and the end face of the capillary 2. The jacket 4 includes a primary coating of an ultraviolet-curable acrylate resin or a silicone resin, and a secondary coating of nylon or a flame-retardant polyester resin. The surface of the jacket 4 in the region where the adhesive is applied is improved in adhesiveness by modifying the surface such as a process of roughening the surface with sandpaper or the like. The adhesive 5 is an epoxy-based adhesive.

In the optical fiber terminal of the present invention shown in FIG. 1, the gap 6 is formed between the step surface of the pipe 1 and the end surface of the capillary 2 as shown in FIGS. The agent 5 flows in and is hardened in a flange shape.
The gap 6 may be a gap enough for the adhesive 5 to enter.

Hereinafter, a case where a thermal stress due to a temperature change is applied to the optical fiber terminal will be specifically described.
Since the adhesive 5 flows into the gap 6 and forms a flange, the adhesive 5 hardened in a flange shape on the step surface of the pipe 1.
Plays a role as a stopper to prevent the adhesive layer from peeling off from the pipe 1. In addition, the surface of the jacket 4 is improved in adhesiveness by modifying the surface such as a treatment to roughen the surface with sandpaper or the like, so that the adhesive 5 is difficult to peel off from the jacket 4. I have. Further, even when the adhesive 5 in contact with the pipe 1 is peeled off, the jacket 4 does not come off from the pipe 1 because the flange-shaped adhesive 5 plays a role of preventing the stepped surface of the pipe 1 from being caught. For this reason, even when the shacket 4 tries to shrink due to aging or temperature change, the jacket 4 does not come off from the pipe 1 and no hollow portion is generated inside the optical fiber terminal.
The breaking strength of the bare fiber is maintained.

Embodiment 2 FIG. 3 is a sectional view of an optical fiber terminal according to a second embodiment of the present invention, and FIG.
FIG. 3 is a diagram showing a bare fiber of the optical fiber terminal of the present invention indicated by. In the figure, 11 is a pipe, 12 is a capillary pressed into the pipe 11, and 14 is a bare fiber 3.
, 15 is an adhesive for fixing the bare fiber 3 and the jacket 14 to the pipe 11 and the capillary 12, and 17 is a groove formed on the outer circumference of the jacket 14. is there. Jacket 14
Is composed of a primary coating of an ultraviolet-curable acrylate resin or silicone resin and a secondary coating of nylon or a flame-retardant polyester resin. The surface of the jacket 14 in the region where the adhesive is applied is improved in adhesiveness by modifying the surface such as roughening the surface with sandpaper or the like. The adhesive 5 is an epoxy-based adhesive. In the second embodiment, the grooves 17
Was applied on the circumference of the jacket, but the groove may be in a state where a part of the jacket is missing. The groove 17 is formed by cutting with a blade or by deforming the jacket by heating.

In the optical fiber terminal of the present invention shown in FIG. 3, since the groove 17 is formed on the outer circumference of the jacket 14 as shown in FIG.
Have flowed in and are cured in a protruding shape.

Hereinafter, a case where a thermal stress due to a temperature change is applied to the optical fiber terminal will be specifically described.
Since the adhesive 15 flows into the groove 17 to form a projection, the adhesive 15 in the form of a protrusion acts as a stopper to prevent the adhesive layer coming into contact with the jacket 14 from being peeled off. Further, even when the adhesive layer in contact with the jacket 14 peels off, the jacket 14 does not come off from the pipe 11 and no hollow portion is generated inside the optical fiber terminal, so that the breaking strength of the bare fiber is maintained.

Embodiment 3 FIG. 5 is a sectional view of an optical fiber terminal according to Embodiment 3 of the present invention. In the figure, 24 is a jacket fixed so as to cover a part of the bare fiber 3, 25 is a bare fiber 3 and a jacket 24.
Adhesive for fixing the pipe to the pipe 1 and the capillary 2,
Reference numeral 7 denotes a groove formed on the outer circumference of the jacket 24. The jacket 24 is composed of a primary coating of an ultraviolet-curable acrylate resin or a silicone resin and a secondary coating of nylon or a flame-retardant polyester resin. The surface of the jacket 24 in the area where the adhesive is applied is improved in adhesiveness by modifying the surface such as a process of roughening the surface with sandpaper or the like. The adhesive 25 is an epoxy-based adhesive. In the third embodiment, the groove 27 is formed on the circumference of the jacket, but the groove may be in a state where a part of the jacket is missing. Groove 2
7 is formed by cutting with a blade or by deforming a jacket by heating.

In the optical fiber terminal of the present invention shown in FIG. 5, since the gap 6 is formed between the step surface of the pipe 1 and the end face of the capillary 2 as shown in FIG. It flows in and is hardened in a flange shape. Further, since the groove 27 is formed on the outer circumference of the jacket 24 as shown in FIG.
Have flowed in and are cured in a protruding shape.

Hereinafter, a case where a thermal stress due to a temperature change is applied to the optical fiber terminal will be specifically described.
Since the adhesive 25 flows into the gap 6 and forms a flange, the adhesive 25 cured in a flange shape on the step surface of the pipe 1 serves as a stopper to prevent the adhesive layer from peeling off from the pipe 1. . Further, even when the adhesive layer of the adhesive 25 in contact with the pipe 1 is peeled off, the jacket 24 does not come off from the pipe 1 because the flange-like adhesive 25 plays a role of preventing the stepped surface of the pipe 1 from being caught. . Further, since the adhesive 25 flows into the groove 27 to form a protrusion, the protrusion-like adhesive 25 plays a role of preventing the groove 27 from being caught, thereby forming the jacket 24.
The adhesive layer in contact with the film becomes difficult to peel off. In addition, jacket 2
Even when the adhesive layer in contact with 4 is peeled off, the jacket 24 does not fall out of the pipe 1. For this reason, since the hollow portion does not occur inside the optical fiber terminal, the breaking strength of the bare fiber is maintained.

Embodiment 4 FIG. FIG. 6 is a sectional view of an optical fiber terminal showing a fourth embodiment of the present invention, and FIG.
FIG. 8 is a cross-sectional view showing a pipe and a capillary of the optical fiber terminal according to the present invention shown in FIG. 8, and FIG. 8 is a cross-sectional view from the side of the pipe shown in FIG. In the figure, 31 is a pipe,
Reference numeral 35 denotes an adhesive for fixing the bare fiber 3 and the jacket 14 to the pipe 31 and the capillary 12, and reference numeral 36 denotes a hole penetrating the pipe 31 from outside to inside. Capillary 1
2 is press-fitted into the pipe 31. In the fourth embodiment, the groove 17 is formed on the circumference of the jacket. However, the groove may be in a state where a part of the jacket is missing.

In the optical fiber terminal of the present invention shown in FIG. 6, the hole 36 penetrating from the outside to the inside of the pipe 31 is formed as shown in FIGS. Are hardened by flowing into the column.
Further, as shown in FIG. 6, since the groove 37 is formed on the outer circumference of the jacket 34, the adhesive 3
5 flows in and hardens to form protrusions.

Hereinafter, a case where a thermal stress due to a temperature change is applied to the optical fiber terminal will be specifically described.
The adhesive 35 hardened in a columnar shape is caught in the hole 36 and serves as a stopper, so that the adhesive layer is hardly peeled off from the pipe 31. Further, even when the adhesive layer of the adhesive 35 in contact with the pipe 31 is peeled off, the jacket 14 and the adhesive 35 do not come off from the pipe 31. In addition, since the adhesive 35 flows into the groove 17 to form a protrusion, the protrusion-like adhesive 35 functions as a stopper to prevent the adhesive from coming into contact with the jacket 34 due to the function of preventing the adhesive 35 from being caught in the groove 17. Further, even when the adhesive layer in contact with the jacket 14 is peeled off, the jacket 14 does not fall out of the pipe 31. For this reason, since the hollow portion does not occur inside the optical fiber terminal, the breaking strength of the bare fiber is maintained.

Embodiment 5 FIG. 9 is a sectional view of an optical fiber terminal showing a fifth embodiment of the present invention, and FIG. 10 is a sectional view of the pipe shown in FIG. 9 as seen from the side. In the figure, reference numeral 41 denotes a flange having an outer side and an inner side having a large or small inner diameter of 2
A pipe formed in a step, 45 is an adhesive for fixing the bare fiber 3 and the jacket 24 to the pipe 41 and the capillary 2, 46 is a projection formed inside the pipe 41, 2
Reference numeral 7 denotes a groove formed on the outer circumference of the jacket 24. The capillary 2 is pressed into a pipe 41. In the fifth embodiment, the projection is formed on the pipe before assembling the optical fiber terminal. However, the projection may be formed by crimping before the adhesive is cured during the assembly of the optical fiber terminal. In addition, even if the outermost end on the side where the jacket of the pipe is inserted is crushed inward, it becomes a projection.

In the optical fiber terminal of the present invention shown in FIG. 9, the projection 46 is formed inside the pipe 41 as shown in FIGS.
Are hardened to avoid depressions. As shown in FIG. 9, a groove 27 is formed on the outer circumference of the jacket 24.
Is formed, the adhesive 45 flows into the groove 27 and is hardened to form a projection.

Hereinafter, a case where a thermal stress due to a temperature change is applied to the optical fiber terminal will be specifically described.
The adhesive 45 that has been hardened in the form of a depression is caught on the projection 46 and serves as a stopper, so that the adhesive layer is less likely to peel off from the pipe 41. Even when the adhesive layer of the adhesive 45 in contact with the pipe 41 is peeled off, the jacket 24 and the adhesive 45
Does not fall out of the pipe 41. Further, since the adhesive 45 flows into the groove 27 to form a projection, the adhesive 45 in the form of a protrusion serves as a stopper to prevent the adhesive layer from coming into contact with the jacket 24. Further, even when the adhesive layer in contact with the jacket 24 is peeled off, the jacket 24 does not fall out of the pipe 41. For this reason, since the hollow portion does not occur inside the optical fiber terminal, the breaking strength of the bare fiber is maintained.

Embodiment 6 FIG. FIG. 11 is a sectional view of an optical fiber terminal showing the sixth embodiment of the present invention, and FIG. 12 is a sectional view showing a pipe and a capillary of the optical fiber terminal of the present invention shown in FIG. In the figure, 51 is a pipe, 52 is a capillary press-fitted into the pipe 51, 55
Is an adhesive for fixing the bare fiber 3 and the jacket 14 to the pipe 51 and the capillary 52, 56 is a taper formed on the end face of the capillary 52, and 58 is a gap formed by the step surface of the pipe 51 and the taper 56. . In addition,
In the sixth embodiment, since the capillary 52 can be inserted until it hits the step surface of the pipe 51, workability is good.

In the optical fiber terminal of the present invention shown in FIG. 11, since the gap 58 is formed as shown in FIG. 12, the adhesive 55 flows into the gap 58 and is hardened in a flange shape. In addition, since the groove 17 is formed on the outer circumference of the jacket 14 as shown in FIG. 11, the adhesive 55 flows into the groove 17 and is hardened in a projecting manner.

Hereinafter, a case where a thermal stress due to a temperature change is applied to the optical fiber terminal will be specifically described.
Since the adhesive 55 flows into the gap 58 to form a flange, the adhesive 55 cured in a flange shape on the step surface of the pipe 51 serves as a stopper to prevent the adhesive layer from peeling off from the pipe 51. . Also, pipe 5
Even when the adhesive layer of the adhesive 55 in contact with 1 is peeled off, the flange-like adhesive 55 plays a role of preventing the stepped surface of the pipe 51 from being caught and thus the jacket 14 is provided with the pipe 5.
There is no escape from 1. Further, since the adhesive 55 flows into the groove 17 to form a projection, the adhesive 55 in the form of a protrusion serves as a stopper to prevent the adhesive from coming into contact with the jacket 14 due to the function of preventing the adhesive 55 from being caught in the groove 17. Further, even when the adhesive layer in contact with the jacket 14 is peeled off, the jacket 14 does not fall out of the pipe 51. For this reason, since the hollow portion does not occur inside the optical fiber terminal, the breaking strength of the bare fiber is maintained.

[0030]

According to the first aspect of the present invention, the adhesive layer of the adhesive in contact with the pipe hardly peels off even when a thermal stress due to temperature change is applied to the optical fiber terminal, and the jacket is formed even when the adhesive layer peels off. Will not fall out of the pipe.

According to the second invention, the adhesive layer of the adhesive in contact with the jacket hardly peels off even when thermal stress due to a temperature change is applied to the optical fiber terminal. Will not fall out of the pipe.

Further, according to the third aspect, the first and second modes are provided.
In addition to the effects of the invention, it is possible to provide an optical fiber terminal in which the adhesive layer of the adhesive is not easily peeled off and the bare fiber is not disconnected even if the adhesive layer is peeled off.

Furthermore, according to the fourth invention, the first and second
In addition to the effects of the invention, it is possible to provide an optical fiber terminal in which the adhesive layer of the adhesive is not easily peeled off and the bare fiber is not disconnected even if the adhesive layer is peeled off.

Further, according to the fifth aspect, the first and second modes are provided.
In addition to the effects of the invention, it is possible to provide an optical fiber terminal in which the adhesive layer of the adhesive is not easily peeled off and the bare fiber is not disconnected even if the adhesive layer is peeled off.

Further, according to the sixth aspect, the first and second modes are provided.
In addition to the effects of the invention, it is possible to provide an optical fiber terminal in which the adhesive layer of the adhesive is not easily peeled off and the bare fiber is not disconnected even if the adhesive layer is peeled off.

[Brief description of the drawings]

FIG. 1 is a sectional view showing Embodiment 1 of an optical fiber terminal according to the present invention.

FIG. 2 is a sectional view showing Embodiment 1 of the pipe and the capillary according to the present invention.

FIG. 3 is a sectional view showing Embodiment 2 of the optical fiber terminal according to the present invention.

FIG. 4 is a sectional view showing Embodiment 2 of a jacket according to the present invention.

FIG. 5 is a sectional view showing Embodiment 3 of the optical fiber terminal according to the present invention.

FIG. 6 is a sectional view showing an optical fiber terminal according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view showing a fourth embodiment of a pipe according to the present invention.

FIG. 8 is a sectional view showing a fourth embodiment of a pipe according to the present invention.

FIG. 9 is a sectional view showing Embodiment 5 of an optical fiber terminal according to the present invention.

FIG. 10 is a sectional view showing Embodiment 5 of the pipe according to the present invention.

FIG. 11 is a sectional view showing an optical fiber terminal according to a sixth embodiment of the present invention.

FIG. 12 is a sectional view showing Embodiment 6 of a pipe and a capillary according to the present invention.

FIG. 13 is a sectional view showing a conventional optical fiber terminal.

FIG. 14 is a sectional view showing a conventional optical fiber terminal.

[Explanation of symbols]

Reference Signs List 1 pipe 2 capillary 3 bare fiber 4
Jacket 5 adhesive 6 gap 11 pipe 1
2 Capillary 14 Jacket 15 Adhesive 1
7 groove 24 jacket 25 adhesive 27 groove
31 pipe 34 jacket 35 adhesive 36 hole 41
Pipe 45 Adhesive 46 Projection 51 Pipe 52 Capillary 55
Adhesive 56 Taper 58 Gaps 61 Pipe 62 Capillary 63 Bare fiber 64 Jacket 65 Adhesive

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Saka ▲ Zaki ▼ 2-3-2 Marunouchi 2-chome, Chiyoda-ku, Tokyo F-term (reference) 2H036 KA00 QA12 QA23

Claims (6)

[Claims] 1. A pipe having an inner side formed in two stages with large and small inner diameters, a capillary provided inside the pipe, a bare fiber inserted into the capillary, and a jacket covering the bare fiber, A gap is formed between the step surface of the pipe and the end face of the capillary, and the pipe, the capillary, the bare fiber, and the jacket are filled with an adhesive in a gap formed by the pipe and the capillary. Bonded optical fiber terminals. 2. A pipe, a capillary provided inside the pipe, a bare fiber inserted into the capillary, and a jacket covering the bare fiber,
An optical fiber terminal in which a groove is provided on the outer periphery of the jacket, and the pipe, the capillary, the bare fiber, and the jacket are bonded so that an adhesive is filled in the groove provided on the outer periphery of the jacket. 3. A pipe having an inner side formed in two stages with large and small inner diameters, a capillary provided inside the pipe, a bare fiber inserted into the capillary, and a jacket covering the bare fiber, A gap is formed between the step surface of the pipe and the end face of the capillary, a groove is provided on the outer periphery of the jacket, and an adhesive is provided in a gap formed by the pipe and the capillary and a groove provided on the outer periphery of the jacket. An optical fiber terminal in which the pipe, the capillary, the bare fiber, and the jacket are bonded so as to be filled. 4. A pipe, a capillary provided inside the pipe, a bare fiber inserted into the capillary, and a jacket covering the bare fiber,
A hole penetrating from the outside to the inside of the pipe is provided, a groove is provided on the outer periphery of the jacket, and an adhesive is filled in the hole penetrating from the outside of the pipe to the inside and the groove provided on the outer periphery of the jacket. An optical fiber terminal in which the pipe, the capillary, the bare fiber, and the jacket are bonded as described above. 5. A pipe having an outer periphery formed in two stages with large and small outer shapes, a capillary provided inside the pipe, a bare fiber inserted into the capillary, and a jacket covering the bare fiber, A projection is provided inside the pipe, a groove is provided on the outer periphery of the jacket, and
An optical fiber terminal in which the pipe, the capillary, the bare fiber, and the jacket are bonded so that an adhesive is filled in a groove provided on an outer periphery of the jacket. 6. A pipe in which the inside is formed in two steps with large and small inside diameters, a capillary provided inside the pipe and having a tapered end face, a bare fiber inserted into the capillary, and the bare fiber. A covering jacket, forming a gap between the step surface of the pipe and the tapered surface of the capillary, providing a groove on the outer periphery of the jacket,
An optical fiber in which the pipe, the capillary, the bare fiber, and the jacket are bonded so that an adhesive is filled in a gap formed by a tapered surface of the pipe and the capillary and a groove provided on an outer periphery of the jacket; Terminal.