JPH10268155A - Optical fiber terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of an optical fiber terminal and facilitate the assembling work by forming the insertion hole of a capillary serving as the hold section of optical fiber glass strands into an elliptic shape. SOLUTION: An optical fiber and a ferrule are fixed at an optical fiber terminal by an adhesive, and the elliptic insertion hole 6 of a capillary 1 is formed into an elliptic shape capable of restraining two optical fiber glass strands 3 in the adjacent state. The optical fiber glass strands 3 are inserted into the capillary 1 and fixed by an adhesive 5. The bend of the optical fiber glass strands 3 generated from the end faces of optical fiber coated fiber covers 4 to the insertion section of the capillary 1 can be resolved when the distance from the end faces of the optical fiber coated fiber covers 4 to the capillary 1 is extended.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber terminal in which a plurality of optical fibers are fixed in a single ferrule.

[0002]

2. Description of the Related Art A conventional optical fiber terminal of this type is shown in FIG.
The structure shown in FIG. FIG. 6A is a cross-sectional view showing an example of an optical fiber terminal in which two conventional optical fibers are bonded and fixed in a single ferrule, and FIG.
FIG. 7A is a side view, and FIG. 7 shows an example of a method of using the optical fiber terminal. In FIG. 6, 2 is a frame, 3 is an optical fiber glass wire, 4 is an optical fiber core coating, 5 is an adhesive, 13 is a capillary with a circular insertion hole, 14 is a circular insertion hole, 15 is a dummy fiber,
The 15 dummy fibers are used for the purpose of reducing the amount of adhesive filled in the circular insertion hole 14 and preventing the optical fiber glass wire from moving in the circular insertion hole 14. In FIG. 7, 11 is a ferrule, 16 is an optical fiber, 17 is a single-core optical connector, 18 is a transmitting device,
19 is a large-diameter light receiving device, 20 is an optical signal flow,
It is used in an optical communication system in which one light receiving device receives two different optical signals transmitted from a transmitting device, or an optical communication system in which the same optical signal is transmitted and a communication circuit has a duplex system.

[0003]

The conventional method is generally configured as described above, and the performance required for the optical fiber terminal is such that mechanical stress or damage is applied to the glass fiber of the optical fiber. It is required that a stable state with no optical characteristics and no deterioration in optical characteristics be maintained for a long period of time. In the optical fiber terminal structure shown in FIG. 6, the insertion hole of the capillary is circular, so that the position of the optical fiber glass wire is not restricted and the thickness of the adhesive around the optical fiber glass wire is uneven. Stress concentration at the time of temperature change due to
The compression of the optical fiber glass wire had an effect on the optical properties. Also, since the distance between the optical fiber glass wires in the capillary is increased by inserting a dummy fiber, a method is used in which the light receiving diameter of the light receiving device is enlarged to cope with the spread of the light emitted from the optical fiber terminal. However, there is a problem that the light receiving sensitivity is reduced due to the non-uniform intensity distribution of the light irradiated on the light receiving surface due to the enlargement of the light receiving diameter,
When inserting the dummy fiber into the gap between the optical fiber glass wire and the insertion hole during the insertion of the dummy fiber, the glass strength is degraded due to excessive contact with the optical fiber glass wire, and the assembly work by handling the dummy fiber There were problems such as a decrease in efficiency.

The present invention has been made to solve the above problems, and has as its object to improve the reliability of an optical fiber terminal and to facilitate the assembling work.

[0005]

According to a first aspect of the present invention, there is provided an optical fiber terminal for holding an insertion hole of a capillary, which is a holding portion of an optical fiber glass strand, in a state where two optical fiber glass strands are adjacent to each other. With the elliptical shape, a stable fixing structure without mechanical stress is obtained.

Further, in the optical fiber terminal according to the second invention, the insertion hole of the capillary which is the holding portion of the optical fiber glass wire has an elliptical shape for holding the two optical fiber glass wires in an adjacent state, By providing a pipe with an inner taper for bundling two optical fiber glass wires, the work of inserting the optical fiber into the ferrule is facilitated.

Further, in the optical fiber terminal according to the third invention, the insertion hole of the capillary which is the holding portion of the optical fiber glass wire has an elliptical shape for holding the two optical fiber glass wires in an adjacent state, By providing an inner taper on the frame for bundling two optical fiber strands,
An object of the present invention is to facilitate the work of inserting an optical fiber into a ferrule and reduce the number of parts.

In the optical fiber terminal according to a fourth aspect of the present invention, the shape of the insertion hole of the capillary which is the holding portion of the optical fiber glass strand is approximated to the arrangement state of the optical fiber glass strand in the ferrule. Thus, a stable fixing structure without mechanical stress is obtained.

In the optical fiber terminal according to a fifth aspect of the present invention, a mark indicating the position of the optical fiber glass strand held in the ferrule is provided on the outer peripheral surface of the ferrule, so that the position of the optical fiber glass strand in the ferrule is provided. Is to clarify.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing Embodiment 1 of the present invention. FIG. 1 (b) is a cross-sectional view showing an optical fiber terminal, and FIG. 1 (a) is a side view of FIG. 1 (b). In FIG.
1 is a capillary, 2 is a frame, 3 is an optical fiber glass wire, 4 is an optical fiber core coating, 5 is an adhesive, and 6 is an elliptical insertion hole.

The shape of the elliptical insertion hole 6 of the capillary 1 is
The optical fiber glass wire 3 is formed into an elliptical shape that can be constrained in an adjacent state, and the optical fiber glass wire 3 is inserted into the capillary 1 and fixed with an adhesive 5. The bending of the optical fiber glass wire 3 generated between the end face of the optical fiber core coating 4 and the insertion portion of the capillary 1 is achieved by increasing the distance from the end face of the optical fiber core coating 4 to the capillary 1. It is possible to eliminate degradation of optical performance due to bending of the fiber.

Embodiment 2 FIG. Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a view showing Embodiment 2 of the present invention, FIG. 2 (b) is a sectional view showing an optical fiber terminal, and FIG. 2 (a) is a side view of FIG. 2 (b). In FIG. 2, 1 is a capillary, 2 is a frame, 3 is an optical fiber glass wire, 4 is an optical fiber core coating, 5 is an adhesive, 6 is an elliptical insertion hole, and 7 is an inner tapered pipe.

The shape of the elliptical insertion hole 6 of the capillary 1 is
The two optical fiber glass wires 3 are formed into an elliptical shape that can be constrained in an adjacent state, and the two optical fiber glass wires 3 are bundled at a tapered portion of an inner tapered pipe 7, inserted into the capillary 1, It is a structure to fix. In addition, the bending of the optical fiber glass wire 3 generated between the end face of the optical fiber core coating 4 and the insertion portion of the capillary 1 is performed by increasing the entire length of the inner tapered pipe 7 to improve the optical performance due to the bending of the optical fiber. It is possible to eliminate the deterioration.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a diagram showing Embodiment 3 of the present invention. FIG. 3 (b) is a sectional view showing an optical fiber terminal, and FIG. 3 (a) is a side view of FIG. 3 (b). In FIG. 3, reference numeral 1 denotes a capillary, 3 denotes an optical fiber glass wire, 4 denotes an optical fiber core coating, 5 denotes an adhesive, 6 denotes an elliptical insertion hole, and 8 denotes an inner tapered frame.

The shape of the elliptical insertion hole 6 of the capillary 1 is
The two optical fiber glass wires 3 are formed into an elliptical shape that can be constrained in an adjacent state, and the two optical fiber glass wires 3 are inserted into the capillary 1 while being bundled at the tapered portion of the inner tapered frame 8, It is a structure to fix. still,
The bending of the optical fiber glass wire 3 generated between the end face of the optical fiber core coating 4 and the insertion portion of the capillary 1 is caused by deterioration of the optical performance due to the bending of the optical fiber by increasing the taper length of the inner tapered frame 8. Can be eliminated.

Embodiment 4 Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a view showing Embodiment 4 of the present invention, FIG. 4 (b) is a sectional view showing an optical fiber terminal, and FIG. 4 (a) is a side view of FIG. 4 (b). In FIG. 4, 2 is a frame, 3 is an optical fiber glass wire, 4 is an optical fiber core coating, 5 is an adhesive, 9 is a capillary, and 10 is a triangular insertion hole.

The triangular insertion hole 10 of the capillary 9 has a triangular shape capable of constraining the three optical fiber strands 3 adjacent to each other. The optical fiber glass strand 3 is inserted into the capillary 9 and the adhesive 5 It is a structure that is fixed with.
When a plurality of optical fibers are used, the arrangement method of the optical fiber glass wires 3 is expected to be various, but the same effect can be obtained by adjusting the shape of the insertion hole of the capillary to each arrangement state. The bending of the optical fiber glass wire 3 generated between the end face of the optical fiber core coating 4 and the insertion portion of the capillary 9 with the polygonal insertion hole is caused by the capillary 9 having the polygon insertion hole from the end face of the optical fiber core coating 4. By increasing the distance to, it is possible to eliminate the deterioration of the optical performance due to the bending of the optical fiber.

Embodiment 5 Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. 5A and 5B show a fifth embodiment of the present invention. FIG. 5B is a sectional view showing an optical fiber terminal, and FIG. 5A is a side view of FIG. 5B. In FIG. 5, 1 is a capillary, 3 is an optical fiber glass wire, 4 is an optical fiber core coating, 5 is an adhesive, 6 is an elliptical insertion hole, 11 is a ferrule, and 12 is a cutout.

In the optical fiber terminal shown in the first embodiment, a notch 12 is provided at a predetermined position on the outer periphery of the ferrule 11 with respect to the rotational position of the elliptical insertion hole 6 of the capillary 1. Thereby, the notch 1 of the ferrule 11 is formed between the ferrule 11 and the peripheral device for connecting the optical fiber terminal.
By using 2 as the rotation reference, it is possible to define the rotation position of the optical fiber glass strand. The same effect can be obtained by using a mark such as a key pin or a display as a method other than the notch.

[0020]

According to the first to fifth inventions, the first embodiment
In the optical fiber terminal in which a plurality of optical fibers are fixed to a single ferrule as shown in FIGS. 5 to 5, the shape of the optical fiber glass wire insertion hole of the capillary is approximated to the arrangement shape of the optical fiber glass wire to be inserted. By making the thickness of the adhesive uniform, torsion of the optical fiber, stress concentration due to temperature change, reduction in sensitivity due to enlargement of the light receiving diameter of the light receiving device, deterioration of glass strength and insertion efficiency of dummy fiber insertion work Can be solved, and improvement of long-term reliability and assembly workability can be remarkably expected.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing Embodiment 2 of an optical fiber terminal according to the present invention.

FIG. 3 is a diagram showing Embodiment 3 of an optical fiber terminal according to the present invention.

FIG. 4 is a diagram showing Embodiment 4 of an optical fiber terminal according to the present invention.

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

FIG. 6 is a diagram showing the structure of a conventional optical fiber terminal.

FIG. 7 is a diagram illustrating an example of an optical communication system in which an optical fiber terminal is used.

[Explanation of symbols]

1 Capillary, 2 Frame, 3 Optical Fiber Glass Wire, 4 Optical Fiber Coating, 5 Adhesive, 6 Elliptical Insertion Hole, 7 Inside Tapered Pipe, 8 Inside Tapered Frame, 9 Capillary, 10 Triangle Insertion Hole, 1
Reference Signs List 1 ferrule, 12 notch, 13 capillary with circular insertion hole, 14 circular insertion hole, 15 dummy fiber, 16 optical fiber, 17 single-core optical connector, 18
Transmitter, 19 Large-diameter light receiver, 20 Optical signal flow.

Claims (5)

[Claims] 1. An optical fiber comprising: two optical fibers; and a ferrule in which a frame holding a core coating of the optical fiber is attached to a capillary holding a glass strand of the two optical fibers. And the ferrule is fixed to the capillary by an adhesive, and the capillary is provided with an elliptical insertion hole for holding the glass wires of the two optical fibers adjacent to each other, and the two optical fibers An optical fiber terminal characterized in that the glass strands of (1) and (2) are affixed with an adhesive adjacent to each other in a single ferrule. 2. A ferrule comprising: two optical fibers; and a frame for holding a core coating of the optical fibers attached to a capillary for holding a glass strand of the two optical fibers, In the optical fiber terminal where the ferrule and the ferrule are fixed with an adhesive, an elliptical insertion hole for holding the glass wires of the two optical fibers adjacent to each other is provided in the capillary.
Incorporating a pipe with an inner taper for bundling the glass strands of two optical fibers, and the glass strands of the two optical fibers are fixed to each other with an adhesive in a single ferrule. Optical fiber terminal. 3. A ferrule comprising: two optical fibers; and a capillary holding a glass wire of the two optical fibers and a frame holding a core coating of the optical fibers attached to the capillary. An elliptical insertion hole for holding the glass wires of two optical fibers adjacent to each other in an end of the optical fiber in which the fiber and the ferrule are fixed with an adhesive; An optical fiber terminal, wherein an inner taper for bundling glass fibers of a fiber is provided, and the glass fibers of the two optical fibers are fixed to each other adjacently in a single ferrule with an adhesive. 4. A ferrule having three or more optical fibers and a frame for holding a core coating of the optical fibers on a capillary for holding a glass wire of the three or more optical fibers, In an optical fiber terminal in which the optical fiber and the ferrule are fixed with an adhesive,
An insertion hole having a shape similar to the glass wire array of three or more optical fibers is provided in the capillary, and the glass wires of the three or more optical fibers are fixed with an adhesive in a single ferrule. An optical fiber terminal, characterized in that: 5. The optical fiber according to claim 1, wherein a mark indicating a glass wire position of the optical fiber fixed in the ferrule is provided on an outer peripheral surface of the ferrule. Terminal.