JPH05264876A - Method for working optical fiber ribbon - Google Patents

Abstract

PURPOSE:To obviate the generation of errors by a fluctuation in the front ends of optical fibers at the time of working the end faces of respective optical fibers by compressively deforming and crimping a metallic tube near to the front end of the plastic coating layer of an optical fiber ribbon. CONSTITUTION:The optical fiber ribbon 1 is constituted by forming the primary and secondary plastic film layers 2 on 4 pieces of the arrayed single mode optical fibers 4. The metallic tube 3 to be fitted to the ribbon 1 is formed to a flat section by compressively deforming a cylindrical tube made of bronze. The metallic tube 3 having the flat section is fitted near to the front end of the plastic coating layer 2 of the tape 1. This metallic tube 3 is compressively deformed and crimped by using a small-sized crimping tool. The part forward of his metallic tube 3 is immersed into a trichloroethylene solvent, by which the coating layer 2 in this part is removed. As a result, the generation of errors at the front end 5 of the respective optical fibers 4 is substantially obviated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing an optical fiber tape in which the position of each fiber tip of the optical fiber tape is fixed by a pressure-bonded metal tube so as to prevent unevenness of each fiber tip.

[0002]

2. Description of the Related Art At present, large-scale computers have rapidly increased the amount of information processing and are required to perform high-speed processing. Therefore, there is a demand for a multi-channel optical circuit using a multi-fiber rather than a single-fiber. It is increasing rapidly. Although the melt drawing method, polishing method, or etching method, which is the end face processing method for a single-core optical fiber, is generally effective for a single-core optical fiber, but when applied to a multi-core optical fiber, it is not suitable for manufacturing or performance. There are many problems, and JP-A-58-152213 only exists as a conventional example.

In Japanese Patent Laid-Open No. 58-152213, the tip of each optical fiber in an optical fiber array is made to match and conical by immersing it in an etching solution, and finally the cut end is heated and melted to be spherical. Even if the end of the optical fiber array can be made into a conical shape by this processing method, the obtained conical shape does not become so long, and in addition to the problem that the clad part covers the core end face and the core end face becomes smaller in the tip spherical part of the optical fiber. Moreover, in these conventional processing methods, it cannot be said that the tips of the respective optical fibers coincide with each other in the strict specifications that the tip error of the respective fibers is 10 μm or less.

[0004]

In a multi-channel optical circuit used in a large computer, the tip error of each fiber in an optical fiber array is, for example, 1 μm or less in LD, P
There is a strict demand for D to be 10 μm or less. The misalignment of the fiber tips in the optical fiber tape causes a tip error of several tens of μm even if the fiber tips are almost completely aligned during the processing work and the tape is simply mishandled. I will end up.

Therefore, the inventors of the present invention have conducted various studies in order to prevent the fiber tip of the optical fiber tape from being uneven, and as a result, before or after the end face processing of the optical fiber tape, a metal tube was formed on the plastic coating layer. Provided is a method for processing an optical fiber tape, which fixes the position of each fiber tip of the optical fiber tape by fitting and crimping. Another object of the present invention is to provide a method of processing an optical fiber tape, which can hermetically seal the boundary between the plastic coating layer and the metal film in the optical fiber tape by means of a pressure-bonded metal tube.

[0006]

In order to achieve the above object, the method of the present invention comprises a multi-fiber optical fiber tape 1 (FIG. 1).
Before the end surface processing, the metal tube 3 having a flat cross section is fitted in the vicinity of the tip of the plastic coating layer 2 of the optical fiber tape 1, and the metal tube is compressed and deformed to be fixed by crimping. The number of optical fibers 4 in the optical fiber tape 1 is two or more, and is generally a multi-core of 4 to 8 cores.

In the method of the present invention, the plastic coating layer 2 at the tip of the optical fiber tape 1 may be removed and the exposed tip of each optical fiber 4 may be coated with a metal film 6 of nickel or the like (FIG. 6). .. Flat section metal tube 3
If the metal coating 6 is coated on the tip of each optical fiber, the plastic coating layer 2 in the optical fiber tape 1
It is preferable that the metal tube 3 is fitted between the front end of the metal tube 6 and the rear end of the metal film 6 and the metal tube 3 is pressure-bonded at that position.

The end face processing of each optical fiber tip 5 in the optical fiber tape 1 is generally a diameter-reducing front sphere processing as shown in FIGS. 3 and 4. In the method of the present invention, as illustrated in FIG. 6 or 7, the end surface of each optical fiber can be polished to a predetermined angle such as flat or oblique.

The metal tube 3 may be formed by flatly compressively deforming the tubular tube 7 (see (1) of FIG. 2) or by forming the flat cross section from the beginning. The length of the metal tube 3 is not particularly limited and may be about 2 mm, and the inner diameter thereof is as small as possible within the range in which the plastic coating layer 2 of the optical fiber tape 1 can be inserted, and pressure bonding processing is possible and elasticity is obtained. It is preferable that it is rich in metal. The material of the metal tube 3 is selected from copper or a copper alloy such as phosphor bronze.

In the method of the present invention, the metal tube 3 having a flat cross section is fitted to the optical fiber tape 1, and then the metal tube 3 is compressed and deformed from the outside by a small pressure bonding device (not shown) to perform pressure bonding. The crimping device used in the present invention is, for example, a small tool similar to a manual tool for a sleeve for fixing a crimp terminal to an electric wire.

[0011]

According to the method of the present invention, since the metal tube 3 is compressed and deformed and pressed in the vicinity of the tip of the plastic coating layer 2 of the optical fiber tape 1, the occurrence of an error at the tip 5 of each optical fiber 4 is almost eliminated. .. Such an effect of preventing unevenness of the fiber tip 5 is effective even if the metal tube 3 is fitted and crimped by compression deformation after processing the end face of each optical fiber 4.

The metal tube 3 having a flat cross section is pressure-bonded between the front end of the plastic coating layer 2 of the optical fiber tape 1 and the rear end of the metal coating 6 if the metal coating 6 is coated on the tip of each optical fiber. It is preferable. With this metal tube 3, the boundary between the plastic coating layer 2 and the metal coating 6 in the optical fiber tape 1 can be made airtight.

[0013]

EXAMPLES Next, the present invention will be explained based on examples. Example 1 An optical fiber tape 1 shown in FIG. 1 has primary and secondary plastic film layers 2 formed on four single mode optical fibers 4 (core diameter 10 μm, cladding diameter 125 μm) arranged in parallel. .. Metal tube 3 that fits on the tape 1
(See (2) in Fig. 2) has an inner diameter of 1.0 mm and a thickness of 0.5 m.
The inner diameter of the short side is 0.5m when the tubular tube 7 made of phosphor bronze (see (1) in Fig. 2) of m and length of 2.0mm is compressed and deformed.
m, and an outer width of 0.9 mm.

The metal tube 3 having a flat cross section is fitted in the vicinity of the tip of the plastic coating layer 2 of the optical fiber tape 1, and the metal tube 3 is compressed and deformed by a small pressure bonding tool (not shown) to be pressure bonded. Then, the front of the tape from the metal tube 3 is dipped in a solvent of trichlorethylene to remove the plastic film layer 2 at that portion.

In FIG. 3, the arc heating apparatus is arranged between the electrode rods 10 and 10 so that the discharge heating temperature at a predetermined position of the optical fiber 4 becomes uniform, and the electric field in each optical fiber 4 becomes substantially uniform. Line up. Next, when one end of the heat-softened optical fiber tape is pulled and stretched to reduce the diameter, the fiber diameter of the reduced diameter portion is about 50 μm.
become. As shown in FIG. 4, when the thin portion of the optical fiber 4 is immersed in the etching solution 11 of hydrogen fluoride for about 30 minutes and the optical fiber is cut at the thin portion, the optical fiber 4
In the etching solution, the clad thickness of the small diameter portion becomes thinner in a taper shape.

The tip of the small-diameter portion of the optical fiber 4 is heated and melted again by arc discharge to be spherically shaped to have a diameter of 20 μm. As a result, the tip positions of the respective fibers of the optical fiber tape 1 are almost completely matched. Regarding this optical fiber tape 1, the error in spheroidizing the diameter of 20 μm is ± 3 μm and the tip error of each fiber is ± 1 μm. For the optical fiber array, the tip error of each fiber is, for example, 1 μm or less in LD,
It is possible to meet the demand for PD of 10 μm or less.

Example 2 With respect to the optical fiber tape 1 used in Example 1, the plastic film 2 at a predetermined portion was removed and the electrode rod of the arc discharge device was arranged so that the discharge heating temperature became uniform at the predetermined portion of the optical fiber 4. The optical fiber tape placed between 10 and 10 is softened by heating, and one end of the optical fiber tape is pulled and stretched to reduce the diameter.
Thereafter, the optical fiber tape 1 is processed in the same manner as in Example 1.
The tip of each of the optical fibers 4 in FIG.

Next, the metal tube 3 having a flat cross section is fitted in the vicinity of the tip of the plastic coating layer 2 of the optical fiber tape 1, and the metal tube 3 is compressed and deformed by using a small crimping tool (not shown) for crimping. To do. As a result, even if the optical fiber tape 1 is mishandled and bent, a tip error does not occur, and the fiber tip positions of the optical fiber tape 1 are always almost completely matched.

Example 3 A predetermined portion of the optical fiber tape used in Example 1 is immersed in a solvent of trichlorethylene to remove the plastic film layer 2 at the predetermined portion. Each exposed optical fiber 15 (Fig. 5)
Is coated with a carbon film 19 (FIG. 6) in advance, and a base metal and a nickel film 6 (FIG. 6) having a thickness of 2.5 μm are further coated thereon. After cutting this optical fiber tape to a length of 1 m, a metal tube 3 having a flat cross section is fitted between the front end of the plastic coating layer 2 and the rear end of the nickel coating 6 to compressively deform the metal tube. Crimp it. Next, the end surface 14 of each optical fiber 15 is polished so as to form an angle of 8 ° with respect to the flat surface.

The obtained optical fiber tape is used for coupling with a light emitting device 16 such as an LD as illustrated in FIG. Since the incident end of the optical fiber 15 is polished to an angle of 8 °, the light of the light emitting element 16 is not reflected by the optical fiber 2 to damage the element or generate noise. Further, even in the optical connector used in the middle of the transmission path, it is preferable to polish the end face 14 of the optical fiber 15 at an angle of 8 ° to prevent far-end reflection.

Example 4 An 8-fiber optical fiber tape 20 (FIG. 8) was treated in the same manner as in Example 3, the surface was coated with a base metal and a nickel film 6 having a thickness of 2.5 μm, and a metal tube having a flat cross section was used. 3 is fitted between the front end of the plastic coating layer 20 and the rear end of the nickel coating 6 and pressure-bonded. Solder plating is further applied to the tip portion (length 33 mm) of each optical fiber 21 in the tape 20 to form a solder plating layer having a thickness of 5 μm.

As shown in FIG. 8, each optical fiber 21 is inserted and arranged in the V-shaped groove 23 of the groove-shaped chip 22, hot pressed from above, and the end portions are collectively soldered and fixed. .. The end face of the optical fiber 21 is polished together with the chip 22 so as to form an angle of 8 °. The obtained optical fiber tape 20 is used when it is combined with the light emitting element 16 such as an LD, like the tape obtained in Example 3.

Example 5 An eight-fiber optical fiber tape 20 was treated in the same manner as in Example 4, and then each optical fiber 21 was processed as shown in FIG.
Is fitted into the V-shaped groove 23 of the groove-shaped chip 22, and the whole end is collectively soldered and fixed. Optical fiber 21
The end face 24 (FIG. 7) is polished together with the tip 22 to form an angle of 45 °, and after the end face is polished, the tip 22 is heated to remove the tip.

At the tip of the optical fiber 21, only KCl of about 2 mm from the polishing end face is KCl.
Immerse in a solution containing 1 mol / l. And the optical fiber 21
By electrolysis with the anode as the anode, the solder plating and the nickel coating 6 and the carbon coating 19 in the vicinity portion 25 are electrolytically removed. As a result of entering light into the optical fiber 21 as shown in FIG. 7, it is possible to confirm outgoing light that is perpendicular to the axial direction in any of the parallel optical fibers.

As shown in FIG. 7, the optical fiber tape 20 is used when it is combined with the light receiving element 26 such as PD or APD. In the optical fiber tape 20, the optical fiber 2
The optical signal 27 passing through 1 can be bent at a right angle and made incident on the light receiving element 26. The optical fiber tape 20 can be installed parallel to the substrate on which the light receiving element 26 is attached, and the installation area can be saved.

[0026]

According to the method of the present invention, since the metal tube is compressed and deformed in the vicinity of the tip of the plastic coating layer of the optical fiber tape and pressure-bonded, no error occurs due to the variation of the tip of the optical fiber when the end face is processed. .. Also,
By bending the tape after the end face processing, the misalignment of the tips of the fibers does not occur, and the error of the tips of the fibers hardly occurs. Such an effect of preventing unevenness of the fiber tips is effective even if a metal tube is fitted and crimped by compression deformation after the end face processing of each optical fiber.

The metal tube used in the method of the present invention may have a tubular shape that is compressed and deformed into a flat shape, or may be formed into a flat cross section from the beginning.
If the tip of each optical fiber is coated with a metal film, the optical fiber tape is crimped between the front end of the plastic coating layer and the back end of the metal film, and this metal tube prevents the metal film from peeling during use. it can.

[Brief description of drawings]

FIG. 1 is an enlarged schematic cross-sectional view showing a state in which a metal tube is pressure-bonded to a plastic coating layer of an optical fiber tape.

FIG. 2 is an enlarged perspective view showing a tubular tube and a flat-sectioned metal tube used in the method of the present invention.

FIG. 3 is a schematic side view showing a state in which a multicore optical fiber is heated and softened or heated and melted.

FIG. 4 is a schematic cross-sectional view showing a state in which the small diameter portion of each optical fiber is immersed in an etching solution and cut.

FIG. 5 is a schematic cross-sectional view showing an enlarged view of another method of the present invention.

FIG. 6 is a schematic vertical sectional view showing a state in which an optical fiber tape is combined with a light emitting element.

FIG. 7 is a schematic vertical sectional view showing a state in which an optical fiber tape is combined with a light receiving element.

FIG. 8 is a schematic vertical cross-sectional view showing an enlarged state in which each optical fiber is fitted and arranged in a V groove of a groove-shaped chip.

[Explanation of symbols]

 1 optical fiber tape 2 plastic coating layer 3 metal tube 4 optical fiber 5 optical fiber tip 6 metal coating 7 tubular tube

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Kurobane 2-5, Kusunekita-machi, Neyagawa-shi, Osaka Kyowa Electric Wire Co., Ltd.

Claims (3)

[Claims] 1. A metal tube having a flat cross section is fitted in the vicinity of the tip of the plastic coating layer of the optical fiber tape before removing the plastic coating layer from the tip of the optical fiber tape and processing the end surface of the optical fiber tape. A method for processing an optical fiber tape, which comprises compressing and deforming a metal tube for compression, fixing the tip position of each optical fiber in the optical fiber core by this metal tube, and then simultaneously processing the end faces of a multicore optical fiber. 2. The plastic coating layer at the tip of the optical fiber tape is removed, the end face of a multi-core optical fiber is processed, and then a metal tube having a flat cross section is fitted in the vicinity of the tip of the plastic coating layer of the optical fiber tape, A method of processing an optical fiber tape, wherein the metal tube is compressed and deformed to be crimped, and the tip position of each optical fiber in the optical fiber core is fixed by the metal tube. 3. The plastic coating layer at the tip of the optical fiber tape is removed, the tip of each optical fiber is coated with a metal film, and then the tip of the plastic coating layer and the back end of the metal coating of the optical fiber tape are removed. A method for processing an optical fiber tape, in which a metal tube having a flat cross section is fitted between them, the metal tube is compressed and deformed to be crimped, and the tip position of each optical fiber in the optical fiber core is fixed by the metal tube. ..