JPH08227026A - Optical fiber connecting member - Google Patents

Abstract

PURPOSE: To shorten the time required for an operation to connect optical fibers by providing the above member with annular stoppers for pressing contact surfaces from outer peripheries by axially sliding on optical fiber clamping members. CONSTITUTION: This optical fiber connecting member has a cylindrical sleeve 1 which has the bore slightly larger than the outside diameter of the clad parts 5a of the optical fibers and has tapered parts 1a at both ends of the bore, a cylindrical sleeve enclosing member 2 which encloses this sleeve 1 and the optical fiber clamping members 3 which are formed dividedly to >=2 members in order to hold and clap the optical fibers at both ends of this sleeve enclosing member 2 and have the contact surfaces 3a for clamping the optical fibers on the respective inner sides. The annular stoppers 4 press the contact surfaces 3a from the outer peripheries by sliding on the optical fiber clamping members 3 in their axial direction. The optical fibers are, therefore, held and connected simply by cutting the optical fibers to a prescribed size, inserting the fibers into the optical fiber clamping members 3 and moving the stoppers 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber connecting member for abutting and fixing end faces of an optical fiber.

[0002]

2. Description of the Related Art As an optical fiber connecting member for abutting and fixing the end faces of an optical fiber, a glass capillary, a silicon plate, or the like is provided with a V groove to position the fiber, and the fiber is fixed with an adhesive or mechanically. Sometimes fixed (Japanese Patent Application Laid-Open No. 53-115088 and Japanese Patent Application Laid-Open No. 2-3).
7307).

[0003]

Among such optical fiber connecting members, those provided with V-grooves can be applied to multi-core connection and are therefore highly useful, but it takes time to assemble and fix them. In addition, when a capillary is used, there are many cases in which the fiber is fixed with an adhesive, and it takes a long time for the adhesive to cure. Therefore, it is an object of the present invention to provide an optical fiber connecting member that solves such a problem and can reduce loss in a short time.

[0004]

SUMMARY OF THE INVENTION An optical fiber connecting member according to the present invention has a cylindrical sleeve having an inner diameter slightly larger than the outer diameter of a clad portion of the optical fiber and having tapered portions at both ends of the inner diameter. And a cylindrical sleeve enclosing member that encloses the sleeve, and the sleeve enclosing member is divided into two or more parts at both ends of the sleeve encapsulating member for sandwiching and gripping the optical fiber, and the inside of each of them is for gripping the optical fiber. An optical fiber gripping member having a contact surface, and a ring-shaped stopper for sliding on the optical fiber gripping member in the axial direction to press the contact surface from the outer periphery. Has a tapered inclination with respect to the axial direction.

[0005]

According to the above construction, the optical fiber connecting member according to the present invention connects the optical fiber by sandwiching the optical fiber by cutting the optical fiber and inserting it into the holding member by a predetermined size, and moving the stopper. Therefore, the time required for connection work can be shortened. Also, by manufacturing the sleeve-containing member with a material close to the thermal expansion coefficient of the optical fiber, it is possible to prevent the optical fiber from being displaced in the optical axis direction due to temperature changes, and to prevent fluctuations in splice loss due to temperature changes. Can be made smaller.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. FIG. 1 is a perspective view showing the structure of the optical fiber connecting member of this embodiment (a).
FIG. 3B is a vertical cross-sectional view (b) showing the clad portion 5 of the optical fiber.
a cylindrical sleeve 1 having an inner diameter slightly larger than the outer diameter of a and having tapered portions 1a at both ends of the inner diameter, and the sleeve 1 and the cylindrical sleeve enclosing member 2 and the enclosing member 2 enclosing the sleeve 1. The optical fiber gripping member 3 is formed at both ends and is divided into two or more parts for gripping and gripping the optical fiber, and the inside of each of them is provided with an optical fiber gripping member 3 having a contact surface 3a for gripping the optical fiber. It has a ring-shaped stopper 4 for sliding on the surface 3 in the axial direction 6 and pressing the contact surface 3a from the outer periphery. Although the contact surface 3a grips the optical fiber coating 5b in FIG. 1, it may grip the cladding 5a.

The sleeve 1 has a diameter of about 1 μm from the outer diameter of the clad portion 5a for holding the end faces of the two optical fibers to be connected.
A cylindrical body having a large inner diameter of about m is formed, and is precisely manufactured from glass, zirconia ceramic, or the like of the same quality as the optical fiber. Both ends of the inner diameter of the sleeve are chamfered to form a taper 1a, and a refractive index discharging hole 1b is provided in the central portion.

The sleeve-containing member 2 is provided to protect the sleeve 1 by incorporating it. Accordingly, the thermal expansion coefficient of the sleeve-containing member 2 is preferably 2.0 × 10 ⁻⁶ m / ° C. or less, preferably the same value as that of the optical fiber, and Invar alloy or quartz glass is used.

As shown in FIG. 1 or 2, the optical fiber holding member 3 is constructed by being divided into 2, 3 or more parts, and has a contact surface 3a for fixing the optical fiber connected to the inside of the tip thereof. It has a space into which the optical fiber coating 5b can be inserted. The outer surface of the optical fiber gripping member 3 is a flat surface or a curved surface with a slightly changed size in the optical fiber axial direction 6. This is because the amount of caulking of the claw portion is adjusted by sliding the ring-shaped stopper 4 on the optical fiber holding member along its axial direction. As the claw member of the optical fiber holding member, an aluminum alloy having good corrosion resistance and workability or a liquid crystal polymer having a small coefficient of thermal expansion, such as Vectra, is suitable. The optical fiber gripping member 3 and the sleeve containing member 2 are integrally coupled by a screw or the like.

Next, a method of connecting optical fibers will be described. First, the coating of the optical fiber is removed by a remover or the like, the surface of the clad portion 5a is wiped with an organic solvent, and the optical fiber is cut into a predetermined length. A refractive index matching agent is previously injected into the sleeve 1. This matching agent has a refractive index close to that of the core of the optical fiber and has a good environment resistance. The optical fiber coating portion 5b is caulked and clamped at a position where the optical fiber is inserted from the introduction port 3b of the optical fiber holding member 3 by a predetermined length. The other optical fibers to be connected are also caulked and connected.

The degree of caulking at this time is shown in FIG.
As shown in (c), when the contact surface is caulked without breaking the covering portion or the covering portion is broken but the clad portion is not broken, or when the contact surface of the optical fiber holding member is the optical fiber. While grasping from above the clad,
The contact surface may be caulked to such an extent that the contact surface is not plastically deformed and the clad is not destroyed. The caulking method is performed by moving the stopper in the direction of arrow 6.

The above-mentioned connection work has required 4 minutes or more and a time for the adhesive to harden in order to assemble the connection member, but it is 3 times including all steps such as the removal of the coating of the optical fiber.
It could be done within minutes. The connection loss is 0.1
In the temperature cycle test in the range of -30 ° C to + 70 ° C within dB, the change in connection loss was within 0.1 dB.

[0013]

As described above, according to the present invention,
The optical fiber can be clamped and connected by simply cutting the optical fiber and inserting the optical fiber into the gripping member by a predetermined size, and moving the stopper, thereby shortening the time required for the connection work. Therefore, it is a connection member particularly suitable for emergency and recovery measures in an optical fiber communication network.
Also, by manufacturing the sleeve-containing member with a material close to the thermal expansion coefficient of the optical fiber, it is possible to prevent the optical fiber from being displaced in the optical axis direction due to temperature changes, and to prevent fluctuations in splice loss due to temperature changes. Can be made smaller. Furthermore, since the inside is filled with the refractive index matching agent, the loss of the optical signal at the connection portion can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view (a) and a vertical sectional view showing a configuration relating to an optical fiber connecting member of the present embodiment.

FIG. 2 is a perspective view showing a configuration relating to another optical fiber connecting member of the present embodiment.

FIG. 3 is a cross-sectional view showing a state in which a claw portion crimps an optical fiber.

[Explanation of symbols]

 1: Sleeve 1a: Taper 1b: Hole 2: Sleeve inclusion member 3: Optical fiber gripping member 3a: Contact surface 3b: Inlet port 4: Stopper 5: Optical fiber 5a: Cladding part 5b: Cover part 6: Moving stopper direction

Claims (8)

[Claims] 1. A cylindrical sleeve having an inner diameter slightly larger than the outer diameter of a clad portion of an optical fiber, and having a tapered portion at both ends of the inner diameter, and a tubular sleeve enclosing member and sleeve for enclosing the sleeve. An optical fiber gripping member having contact surfaces for gripping an optical fiber is provided at both ends of the inner encapsulation member and is divided into two or more parts for gripping and gripping the optical fiber. An optical fiber connecting member having a ring-shaped stopper for sliding on the member in the axial direction and pressing the contact surface from the outer periphery. 2. The optical fiber connecting member according to claim 1, wherein an outer surface dimension of the optical fiber holding member has a taper inclination with respect to an axial direction. 3. The degree to which the contact surface of the optical fiber gripping member grips the coating of the optical fiber from above the coating portion of the optical fiber, or the extent to which the contact surface crimps without breaking the coating portion or the coating portion, but not the cladding portion. The optical fiber connecting member according to claim 1, which is caulked to a certain degree. 4. The optical fiber gripping member is caulked to such an extent that the contact surface does not break the cladding while the contact surface is gripped from above the optical fiber clad.
The optical fiber connecting member according to. 5. The optical fiber connecting member according to claim 3, wherein the caulking amount of the contact surface is adjusted by the taper of the optical fiber holding member. 6. The contact surface of the optical fiber holding member is formed of aluminum or liquid crystal polymer.
Alternatively, the optical fiber connecting member described in 4. 7. The optical fiber connecting member according to claim 1, wherein the sleeve is made of ceramic or glass. 8. The thermal expansion coefficient of the sleeve-containing member is 2.0.
The optical fiber connecting member according to claim 1, wherein the optical fiber connecting member is formed of Invar alloy or quartz glass having a density of × 10 ^-6 m / ° C or less.