JPH01321410A - Production of fiber fusion type optical device - Google Patents

Abstract

PURPOSE:To reduce the cost of equipment and to improve the yield of the optical device by providing the stretching function of a fused part to the optical device itself. CONSTITUTION:Semicylindrical sleeves 25 are slid in the directions parting from each other by utilizing the expansion force generated when an expandable resin 27 is heated. Optical fiber holders 30 are pressed at the end faces of said sleeves 25 and are moved in the directions parting from each other within the cylinder of a sheath 35 by which the fused part is stretched to a desired small diameter. The sheath 35 has the function as a guide of the optical fiber holders 30 and the function as a package to protect the optical coupling part 6 after the completion of the optical device. The need for the equipment having a stretching function is, therefore, eliminated. The cost of the equipment is reduced and the yield of the optical device is improved in this way.

Description

[Detailed Description of the Invention] [Summary] It is an object of the present invention to provide a method for manufacturing a fiber fusion type optical device, which requires low cost equipment and has a high yield of optical devices. A pair of optical fiber holders that face each other and hold two optical fibers whose claddings are closely aligned in parallel, separated by a desired distance, An inner cylinder installed between the pair of optical fiber holders so as to pass through the core hole, two arc-shaped blind holes opening on both end faces of the inner cylinder, and filled into the bottom of the arc-shaped blind holes. a foamable resin, a semi-cylindrical sleeve fitted into the opening side of each of the arc-shaped blind holes, the inner cylinder, and a pair of the semi-cylindrical sleeves.

and a cylindrical mantle that covers the outer peripheral surface of a cylindrical part formed by combining the pair of optical fiber holders, and a clad part corresponding to the heating port provided in the shell part of the inner cylinder is connected to a burner. At the same time, the foamed resin is expanded, and the optical fiber holder is pressed and moved in a direction away from each other within the cylinder of the mantle via the semi-cylindrical sleeve, thereby forming the fused portion. The structure is such that the material is stretched to a desired narrow diameter.

[Industrial application field]

The method of the present invention relates to a method of manufacturing a fiber fusion type optical device.

As shown in Figure 3, recent communication equipment uses optical devices such as optical multiplexers/demultiplexers and optical multiplexers/branchers, which are made by arranging two optical fibers and fusing them at desired points to reduce the diameter. ing.

In FIG. 3, the input side optical fiber 3 and the second output side optical fiber 2 are originally one single mode optical fiber, and are made of quartz glass or the like and have a diameter of 10 μm.
A cladding 8 made of quartz glass or the like having a refractive index smaller than that of the core is provided around the core 7, and the outer periphery of the cladding 8 is protected with a synthetic resin covering material. The outer diameter of this cladding 8 is about 125μ.

Further, the other input side optical fiber 4 and the first output side optical fiber 1 are originally one other single mode optical fiber.

Coat two single-mode optical fibers like this!
After exposing the cladding 8 by exposing the cladding 8, the cladding 8 is aligned in parallel and the intermediate portion is heated to fuse the cladding 8 to form a book.

Then, the core 7A and cladding 8^ are formed by further elongating the core and the cladding, and the two cores 7A are brought close to each other in parallel to form the optical coupling part 6.
It is said that

As described above, the input optical fiber 3 and the other input optical fiber 4 are arranged in parallel on one side of the optical coupling section 6, and the first output optical fiber l and the second output optical fiber are arranged on the other side. The fibers 2 are arranged in parallel to form a fiber fusion type optical device.

The demultiplexing function of the fiber fusion type optical device will be explained in detail below.

From the input side optical fiber 3, the wavelength λ1. λ2 (λ1 × λ2
), the light with wavelength λ2 travels along the transmission path of the original optical fiber and travels through the second output optical fiber 2.

However, the light with wavelength λ leaks into the cladding 88 at the optical coupling part 6, gradually transfers to the other core 7^, transfers to the first output optical fiber 1, and travels through the first output optical fiber l. do. That is, such an optical coupling section 6 has a function of an optical demultiplexer, has a simple structure, and is low in cost.

[Conventional technology]

(a) and (bl in FIG. 4 are diagrams showing the steps of the conventional manufacturing method. In FIG. 4, 40-1 and 40-2 are single-mode optical fibers with the same shape, For the optical fibers 40-1 and 40-2, the coating at the intermediate portion is peeled off to expose a desired length of the cladding.

The fusion device includes a pair of optical fiber holding units 1-10-1 and 10-2 that are slidably mounted on a guide member (not shown) at a desired distance apart. As shown in FIG. 4(a), two optical fibers 40-1 and 40-2 are aligned in parallel, and with the outer circumferential surfaces of the claddings in contact with each other, the coating section is attached to each optical fiber holding unit HO-2. Insert into the axial center groove of 1°10-2, and press the holding plate 11 from above the axial center groove.
-1. Push in 11-2 and connect optical fiber 4゜-1,40
-2 is fixed by the optical fiber holding unit.

Then, the central part of the exposed cladding is heated with a burner 12 to fuse the two optical fibers together to form a -strand.

And optical fiber holding unit 10-1.10-24
- The optical coupling portion 6 is provided by sliding the optical fibers in a direction away from each other and stretching the fused optical fibers to make the core and cladding small in diameter.

After that, the optical fiber is removed from the fusion device, and the optical fiber is removed from the fusion device as shown in Fig.
As shown in b), the exposed part of the cladding including the optical coupling part 6 is covered with a sleeve half 15 made of glass or synthetic resin.
-1, and glue the coated parts of the two optical fibers together near both ends of the sleeve half 15-1 using adhesive 13.
It's stuck in place.

After that, the longitudinal end surface of the other sleeve half 15-2 is aligned with the longitudinal end surface of the previous sleeve half 15-1, and the sleeve half 15-1 and 15-2 are attached using adhesive to form a cylindrical sleeve half 15-1.15-2. The cladding portion protects the exposed optical coupling portion 6.

[Problem to be solved by the invention]

However, in the above conventional method, there is a puff caging process to protect the optical coupling part after the fusion-stretching process, and there is a risk that the optical coupling part, where the cladding part is exposed, may be damaged during handling between this process. .

Furthermore, a highly accurate stretching mechanism is required, which may increase the equipment cost of the apparatus.

The present invention was created in view of these points, and the present invention has been created to provide low-cost equipment and high yield of optical devices.
It is an object of the present invention to provide a method for manufacturing a fiber-fused optical device.

[Means to solve the problem]

In order to achieve the above object, the present invention, as illustrated in FIG. A pair of optical fiber holders 30 are provided which are held facing each other with a distance of .

Further, an inner cylinder 20 having a heating port 23 and an axial hole 21 is provided in the center of the shell, and is installed between a pair of optical fiber holders 30, so that the optical fibers 40-1 and 40-2 can be connected to each other. They are assembled so that the exposed cladding portion passes through the shaft center hole 21.

Two arc-shaped blind holes 24 are provided in the inner cylinder 20, opening at each end face of the inner cylinder 20, and the bottoms of the arc-shaped blind holes 24 are filled with foamable resin 27. Furthermore, each arc-shaped blind hole 24
A semi-cylindrical sleeve 25 is fitted into the opening side of the sleeve.

Inner cylinder 20. A pair of semi-cylindrical sleeves 25. A cylindrical jacket 35 is attached so as to cover the outer peripheral surface of the cylindrical part formed by combining the pair of optical fiber holders 30 as desired.

After that, the heating port 23 of the inner cylinder 20 is heated using the burner 12.
At the same time as the fusion, the optical fiber holder 30 is pushed and moved away from each other within the cylinder of the jacket 35 via the semi-cylindrical sleeve 25, and the fused portion is fused. The optical coupling portion 6 is formed by stretching it to a desired narrow diameter.

(Operation) As described above, the present invention utilizes the expansion force caused by heating the foamable resin 27 to slide the semi-cylindrical sleeves 25 away from each other, and the optical fiber holder 30 is held at the end face of the semi-cylindrical sleeves 25. are pressed and moved in a direction away from each other within the cylinder of the mantle 35, thereby stretching the fused portion to a desired narrow diameter.

In this way, the jacket 35 has the function of a guide for the optical fiber holder 30 and the function of a package that protects the optical coupling section 6 after the optical device is completed.

Therefore, unlike the conventional method, equipment with a stretching function is not required.

In addition, two optical fibers 40-1 and 40-2 are connected to the mantle 3.
The inner tube 20 is fused and stretched within the axial hole 21 of the inner tube 20 housed in the tube 5, and packaged in that state.

Therefore, the optical coupling part is less likely to be damaged and the yield is high.

〔Example〕

The method of the present invention will be specifically explained below with reference to the drawings. Note that the same reference numerals indicate the same objects throughout the figures.

FIG. 1 is a diagram showing the steps of the method of the present invention, and FIG. 2 is a diagram showing the steps of the method of the present invention.
1 is a block diagram showing an embodiment of the present invention in an isolated form; FIG.

The fiber fusion type optical device according to the method of the present invention has a second
As shown in the figure, two optical fibers 40-1°40-2
, an inner cylinder 2 made of heat-resistant metal such as stainless steel, etc.
0, a pair of semi-cylindrical sleeves 25, a pair of optical fiber holders 30, a jacket 35, and a foaming resin filled in the deep part of the arc-shaped blind hole 24 of the inner cylinder 20.

To be more specific, the optical fibers 40-1 and 40-2, which are single mode optical fibers having the same shape, are separated from each other by peeling off the coating at the intermediate portion to obtain a desired length (slightly larger than the length of the inner tube 20 described later). (length), the cladding is exposed.

The inner cylinder 20 has an axial hole 21 at its axial center through which two optical fibers pass through with sufficient margin, and a shell portion of the inner cylinder 20 has an axial hole 21 whose width is approximately equal to the inner diameter of the axial hole 21. parallel to 21,
In addition, a slit 22 communicating with the shaft hole 21 is provided.

Further, a square window-shaped heating port 23 is provided in the center of the shell of the inner cylinder 20.

24 is opened at each end face of the inner cylinder 20,
An arc-shaped blind hole with an approximately semi-circular cross section is provided in the shell of the inner cylinder 20, and is not shown at the bottom of the arc-shaped blind hole 24 (i.e., in the center of the inner cylinder 20). The desired appropriate amount of foamable resin is filled.

Further, a semi-cylindrical sleeve 25 having a flange 25A on its outer end face is configured to be viewed from the opening side of the arc-shaped blind hole 24.

The optical fiber holder 30 has a sufficiently thick disk shape,
Its outer diameter is slightly larger than the □ outer diameter of the inner cylinder 20.

The optical fiber holder 30 is provided with a slit 31 whose bottom substantially coincides with the axis.

The end surface of each optical fiber holder 30 is brought into contact with the end surface on the flange 25A side of the semi-cylindrical sleeve 25 fitted into the inner tube 20, and the inner tube 20. A semi-cylindrical sleeve 25° and an optical fiber holder 30 are combined.

Then, with the two optical fibers 40-1 and 40-2 aligned in parallel, the exposed portion of the cladding is inserted into the inner tube 2.
0, and both ends thereof are inserted into the slits 31 of the respective optical fiber holders 30.

Thereafter, the boundary between the optical fiber coating and the cladding is pushed into the slit 31 and fixed using an adhesive 32.

At this time, the claddings of the two optical fibers 40-1 and 40-2 are exposed, parallel to each other and circumscribed, and the inner cylinder 20
The optical fiber is stretched over the optical fiber holder 30 so as to pass through the axial hole 21 of the optical fiber.

Reference numerals 35-1 and 35-2 denote a pair of mantles made of stainless steel or the like, the radius of which is slightly larger than the radius of the optical fiber holder 30. Also, one half of the cloak 35
-1 is provided with a square window-shaped heating port 36 at a position corresponding to the heating port 23 of the inner cylinder 20.

The length of the outer mantle is greater than (length of inner cylinder + 2 x length of semi-cylindrical sleeve + 2 x length of optical fiber holder).

Inner cylinder 20. Semi-cylindrical sleeve 25. Optical fiber holder 3
0. and the outer mantle half 35- so as to cover the outer peripheral surface of the cylindrical part constructed by combining the optical fibers 40-1 and 40-2.
1 and a mantle half 35-2 are combined and covered, and the mating surfaces are laser welded to form a cylindrical mantle whose inner diameter is slightly larger than the outer diameter of the optical fiber holder 30 (the mantle 35 shown in FIG.
).

t, Inner cylinder 20. A pair of semi-cylindrical sleeves 25° and a pair of optical fiber holders 30 are attached to the above-mentioned jacket half 35-1.
It is desirable to combine the optical fibers in the same way, and then stretch the optical fibers □. □ - A cross-sectional view of the combination as described above is shown in FIG. 1 (a).

At this time, as shown in FIG. 1(a), the inner cylinder 20 and the outer mantle 35 are assembled so that the respective heating ports 23 and 36 are aligned with each other.

As shown in FIG.
1. Fuse the cladding part of 40-2 into one piece.

When the optical fiber reaches a high temperature and is fused, the foamable resin 27 in the inner tube 20 is melted by the radiant heat from the burner 12.
The temperature rises to foaming. □As a result, the foamed resin 27 expands and presses the end faces of the semi-cylindrical sleeves 25, pushing each semi-cylindrical sleeve 25 toward the opening of the arc-shaped blind hole 24. Then, the respective optical fiber holders 30, whose end faces are in contact with the collar portions of the semi-cylindrical sleeve nibs 25, slide in the direction away from each other within the cylinder of the jacket 35.

Therefore, the fused portion of the optical fiber is stretched and becomes thinner, forming the optical coupling portion 6 with a desired small diameter.

After forming the optical coupling part 6, as shown in FIG.
To prevent dust and the like from entering, the mantle 35 is rotated to shift the heating ports 23 and 36 from the position facing the heating ports 23.

Thereafter, the inner wall of the jacket 35 and the end face of the optical fiber holder 30 are bonded with adhesive or laser welded to fix the optical fiber holder 30 and the jacket 35, and the package is soldered.

As described above, the jacket 35 has the function of guiding the optical fiber holder 30 and the function of a package that protects the optical coupling section 6 after the optical device is completed.

Therefore, unlike the conventional method, equipment with a stretching function is not required.

In addition, two optical fibers 40-1 and 40-2 are connected to the mantle 3.
The inner tube 20 is fused and stretched within the axial hole 2I of the inner tube 20 housed in the tube 5, and packaged in that state.

Therefore, the optical coupling part is less likely to be damaged and the yield is high.

C Effects of the Invention As explained above, the present invention is a manufacturing method in which the optical device itself has a function of stretching the fused portion, the equipment is extremely low in cost, and the yield rate of the optical device is reduced. It has excellent practical effects, such as high

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the steps of the method of the present invention, Fig. 2 is a configuration diagram showing an embodiment of the present invention in separated form, Fig. 3 is a cross-sectional view of the optical coupling section, and Fig. 4 is the process of the conventional method. FIG. In the figure, 1 is the first output side optical fiber, 2 is the second output side optical fiber, 3.4 is the input side optical fiber, 6 is the optical coupling part, 12 is the burner, 15-C15-2 is the sleeve semi-opening. , 20 is an inner cylinder, 21 is an axial center hole, 22.31 is a slit, 23.36 is a heating port, 24 is an arc-shaped blind hole, 25 is a semi-cylindrical sleeve, 27 is a foamed resin, 30 is an optical fiber holder , 35 is a cloak. 35-C35-2 indicates a cloak, and 404.40-2 indicates an optical fiber. , ζ te 7th issue (C) Diagram showing the second stage of Hon'yo Ming Shiotaku $ 1 Kuchippontaku Sun Moon Tomo Ishiki Yudubu Tobishi Shakugata Z-Hosu's first hat 戊l No.
2. Figure 2. Figure 3. Figure 4. Figure 4.

Claims (1)

[Claims] Two optical fibers whose claddings are closely aligned in parallel (
A pair of optical fiber holders (30) that hold two locations of the optical fibers (40-1, 40-2) facing each other at a desired distance apart; and a cladding portion of the optical fibers (40-1, 40-2). An inner cylinder (20) is installed between the pair of optical fiber holders (30) so as to pass through the axial hole (21), and two arcs open at both end faces of the inner cylinder (20). Foramen blind (24)
, a foamable resin (
27), and a semi-cylindrical sleeve (25) fitted into the opening side of each of the arc-shaped blind holes (24), and the inner cylinder (20).
, a cylindrical mantle (35) that covers the outer peripheral surface of a cylindrical part formed by combining the pair of semi-cylindrical sleeves (25) and the pair of optical fiber holders (30), The clad part corresponding to the heating port (23) provided in the shell part of the inner cylinder (20) is heated and fused using a burner (12), and the foamable resin (27) is expanded to form the semi-cylindrical part. The optical fiber holder (
30) within the cylinder of the mantle (35) in a direction away from each other to stretch the fused portion to a desired narrow diameter.