JPS6156308A - Manufacture of optical branching device - Google Patents

Abstract

PURPOSE:To obtain a branching device of a stable accuracy, by which a prescribed removing quantity can be known easily, by providing a through-hole in parallel to a core, in the longitudinal direction in a clad of an optical fiber, removing the clad of the through-hole side, in a coupling part, and coupling the removed parts so as to be opposed to each other. CONSTITUTION:A through-hole 5 is provided in parallel to a core 4, in a clad 3 of an optical fiber 2. Subsequently, in a fiber inserting groove 10A of a polishing jig 10, the fiber 2 is set so that the through-hole 5 is in the outside of a U- shape, and a clad removed surface 7 is positioned at the side having the through- hole 5. When polishing is executed in this way, the polishing is executed, seeing a polished state of the through-hole 5, therefore, a polishing quantity can be known. The fibers 2 polished by a prescribed quantity are coupled by joining together each removed surface 7 so as to be opposed to each other and sticking them by an adhesive agent. Accordingly, the removing quantity of the clad can be grasped easily based on the through-hole 5 as a reference, therefore, an optical branching device of a stable accuracy can be manufactured easily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method of manufacturing an optical splitter used in distributing optical signals transmitted through optical fibers.

More specifically, we manufacture an optical splitter that is used to couple two optical fibers so that they match in the longitudinal direction and distribute an optical signal from one optical fiber to the other optical fiber. Regarding the method.

(Prior art and its problems) When a conventional optical branching device is configured by combining a part of two optical fibers in the longitudinal direction, first the optical fibers are Figure 3 (a) bending into a letter shape
Set it in the jig shown in , and polish the cladding of the curved part of the U-shaped bottom by a predetermined amount. The polished parts are brought together so as to face each other, and the two parts are fixed and bonded using, for example, an adhesive to manufacture an optical splitter.

Incidentally, in this type of optical splitter, the degree of branching and coupling differs depending on the distance between the cores of the optical fibers that are coupled.

For this reason, if the amount of polishing of the cladding is not accurate, the characteristics of the manufactured optical splitter will vary, making it difficult to obtain an optical splitter with uniform performance.

(Means for Solving the Problems and Their Effects) In order to solve the problems of the prior art as described above, the present invention combines two optical fibers of a predetermined length with their cores aligned in the longitudinal direction. In the method for manufacturing an optical splitter constituting a splitter main body, the optical fiber of the splitter main body has a through hole provided in the cladding in the longitudinal direction parallel to the core, and at least the side having the through hole at the joining part. This method is characterized in that the cladding of the cladding is removed and the removed portions are placed facing each other to join them together.

When manufactured using this method, it is possible to polish using the through hole as a reference when removing the cladding of the part to be joined, making it easy to maintain a constant removal amount and manufacture optical splitters with consistent precision. can do.

(Example) FIG. 1 is a sectional view of an optical splitter manufactured by the method of the present invention, and 1 is the splitter main body. In the splitter main body 1, two optical fibers 2.2 of a predetermined length are arranged so as to be aligned in the longitudinal direction, and some of them are coupled. The optical fiber 2 has a through hole 5 provided in the cladding 6 in parallel to the core. A part of the cladding is removed at the joining part 6 of the two-party fiber 2.2, and the removed surfaces 7.7 of the cladding are brought together and joined in a state facing each other. The cladding removed surface 7 of the optical fiber 2 is on the side of the through hole 5 provided in the cladding 3, and the through hole 5 is in a state in which the cladding removed surface 7 is removed.

Such a turnout main body 1 is manufactured as follows.

First, two optical fibers a of a predetermined length as shown in FIGS. 2(a) and 2(b) are prepared. In FIGS. 2A and 2B, 3 is a cladding, 4 is a core, and 5 is a through hole provided in the cladding 5, which is provided parallel to the core 4. This optical fiber 2 can be obtained by drilling holes at predetermined positions in the portion corresponding to the cladding 6 during the preform stage and spinning the fiber into an optical fiber using a conventional method. The optical fiber 2 thus obtained is set in the polishing jig 10 shown in FIG. 5(A) in a U-shape as shown in FIG. 3(B),
Polish the curved part of the U-shaped bottom with a glass polisher to create cladding 3.
remove. In FIG. 3(a), IOA is an optical fiber insertion groove. Optical fiber insertion $IOA even before polishing
When setting the optical fiber 2, the through hole 5 is set on the outside of the U-shape so that the surface 7 to be removed by polishing is on the side with the through hole 5.

When the optical fiber 2 is set in the polishing jig 10 and polished as described above, the polishing can be performed while checking the polishing condition of the through holes 5, so that, for example, all the through holes 5 on the surface being polished are polished. If the time when the polishing is completed is the time when the polishing is finished, the amount of polishing can be determined just by looking at the polished surface. The optical fibers 2.2 that have been polished to a predetermined amount in this way are aligned with their respective cladding removed surfaces 7.7 facing each other and fixed with an adhesive to couple the two optical fibers 2.2.

When the clad removed surfaces 7.7 are butted together, applying matching oil to the removed surfaces 7 will make the light branching at the mating surfaces more stable.

(Effects of the Invention) As explained above, the optical splitter of the present invention uses an optical fiber in which a through hole is provided in the cladding parallel to the core,
At least the cladding on the side with the through hole is removed from the part where the optical fibers are connected, so the amount of cladding removed can be easily determined based on the through hole, resulting in stable accuracy. It becomes easy to manufacture an optical splitter.

[Brief explanation of drawings]

Figure 1 is a sectional view of an optical splitter manufactured by the method of the present invention, and Figures 2 (a) and (b) are longitudinal sectional views of an optical fiber used in the optical splitter manufactured by the method of the present invention. and a cross-sectional view. FIG. 3(a) is a sectional view of the optical fiber polishing jig p) used in one embodiment of the method of the present invention, showing a state in which an optical fiber is inserted into the jig. DESCRIPTION OF SYMBOLS 1... Branch main body, 2... Optical fiber, U... Clad, I... Core, 5... Through hole, 6... Coupling part, 7... Clad removal surface 1st Figure 2 (a) (b) Figure 3 (a) World diagram 3 (b)

Claims (1)

[Claims] In a method for manufacturing an optical splitter, in which two optical fibers of a predetermined length are coupled with their cores aligned in the longitudinal direction to form a splitter main body, the optical fibers of the splitter main body are placed in a cladding. A light characterized in that a through hole is provided parallel to the core in the longitudinal direction, and at least the cladding on the side having the through hole is removed from the part to be joined, and the removed parts are brought together facing each other to join the two. Method of manufacturing a turnout.