JPH11223732A - Method for processing edge face of optical fiber and grinder for processing edge face of optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the edge face processing of an optical fiber at the time of PC-connecting a tape-shaped optical fiber core wire. SOLUTION: An optical fiber 1 is exposed at the terminal part of a tape- shaped optical fiber core wire 4, and the surface part at the radial distance of the optical fiber 1 in a vertical direction from the central axial array face of each optical fiber 1 on one side of the central axial array face is cut, and a bending stress is applied to the optical fiber 1 so that the cut can be outside the bending, and each optical fiber 1 is cleavage cut so that the edge face can be formed. In this case, the central axial array face of the optical fiber 1 is matched with the longitudinal direction of a V-shaped grinder face 5 provided on the surface of the grinder 7, and the edge part in the periphery of the cut and edge part at the opposite side to the cut on the edge face of the optical fiber 1 are simultaneously brought into contact with the grinder face 5, and the tape-shaped optical fiber core line 4 or the grinder 7 is allowed to slide to the direction of the central axial array of the optical fiber 1 so that the edge part of each optical fiber edge face can be chamfered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for treating an end face of an optical fiber and a grindstone for treating the end face of an optical fiber used in the method.

[0002]

2. Description of the Related Art As one method for connecting an optical fiber mainly composed of glass such as quartz, a connector connection utilizing physical contact coupling is performed. Physical contact coupling is also called PC coupling, and is a method of pressing the connection end faces together to elastically deform the end faces to make a close contact connection, and it is necessary for the glass to completely contact the butted end faces of the optical fibers.

On the other hand, in the case of an optical fiber mainly composed of glass such as quartz, the surface of the optical fiber is scratched and the optical fiber is subjected to bending stress with the scratch outside, whereby the glass is cleaved based on the scratch. The cutting method is performed as a simple optical fiber cutting method or an end face forming method. FIGS. 7A and 7B are side views showing a method of forming an end face by the cleavage. FIG. 7A shows a state before the cleavage, and FIG. 7B shows a state after the cleavage. In FIG. 7, 20 is an optical fiber mainly composed of glass such as quartz, 21 is a coating made of an ultraviolet curable resin or the like, 22 is a vinyl chloride resin,
It is a protective coating made of nylon resin or the like. The optical fiber 20, the coating 21, and the protective coating 22 constitute an optical fiber core.

First, as shown in FIG. 7A, the coating 21 and the protective coating 22 at the end of the optical fiber are removed to expose the optical fiber 20. Subsequently, a slight scratch 20a is made on the lower side surface portion of the optical fiber 20 with a blade, and a bending stress for bending the distal end portion of the optical fiber 20 upward is applied.
Then, the optical fiber 20 is cleaved from the position of the flaw 20a, and the cleavage surface 20b is substantially perpendicular to the central axis of the optical fiber 20.
Is cut at At this time, 0.1-1 μm as shown in FIG.
Burrs 20c having a height of about m may remain.

[0005] Even if it is attempted to perform PC bonding while leaving the burrs, the burrs become an obstacle and a complete contact surface between the glasses cannot be obtained, resulting in a large coupling loss. Burrs must be removed. As a method of removing such burrs, there is a method of so-called chamfering, in which an edge around an end face is cut off.

When the optical fiber is a single core, the edge portion of the end face is pressed against the grindstone surface while the optical fiber is held obliquely with respect to the rotating grindstone surface, and the edge portion is polished.
By continuing the polishing while slowly turning the optical fiber around the axis, the entire peripheral edge 20d of the end face can be chamfered as shown in FIG. 7C, whereby the burrs are completely removed.

However, in the case of a tape-shaped optical fiber core wire in which a plurality of optical fibers are arranged in parallel and a coating is provided on the outside thereof, the chamfering of the entire end face of the end face of each optical fiber is performed as described above. It was difficult to do it in the same way as with the mind. That is, while holding the optical fiber in an oblique direction with respect to the grindstone, even if the end face of the optical fiber is pressed against the grindstone surface and the optical fiber is rotated around the central axis, the optical fiber interval is narrow. Therefore, it was impossible to rotate the optical fiber because the adjacent optical fiber was an obstacle. Therefore, when PC coupling is to be performed on a tape-shaped optical fiber core, the entire end face has been polished to remove burrs.

[0008]

In the case of a tape-shaped optical fiber, it is difficult to remove burrs remaining at the edge of the end face even if the optical fiber exposed at the end is cut by a cleavage operation. Set the tape-shaped optical fiber core to P
When C bonding was desired, the entire end face was polished as described above. However, in order to polish the entire end face, high-speed polishing is difficult because the polishing is required to be careful not to form a deteriorated layer due to the polishing of the end face, the amount of polishing is increased, and the time required for polishing is long, The cost was high.

According to the present invention, in the case of an optical fiber ribbon, only the burrs and the peripheral edges thereof are chamfered.
An object of the present invention is to provide a method for obtaining an end face capable of PC bonding and a grindstone for treating an end face of an optical fiber used for the method.

[0010]

In the method for treating an end face of an optical fiber according to the present invention, a plurality of coated optical fibers composed mainly of glass such as quartz are coated in parallel and arranged outside thereof. The optical fiber is exposed at the end of the tape-shaped optical fiber core wire provided with the collective coating, and is located on one side of the central axis arrangement surface of the optical fiber and the radial distance of each optical fiber from the central axis arrangement surface in the vertical direction. The optical fiber is subjected to a bending stress so that the surface is located outside of the bend, and the optical fiber is cleaved and cut to form an end face. The center axis arrangement surface of the optical fiber is aligned in the longitudinal direction of the grindstone surface, and the edge portion of the end surface of the optical fiber around the flaw and the edge portion on the opposite side of the flaw are simultaneously brought into contact with the grindstone surface, Tape-shaped optical fiber core wire or whetstone By sliding the central axis direction of arrangement of the optical fiber, and performing chamfering of the edge portions of each optical fiber end face 2 points.

Further, the center axis arrangement surface of the optical fibers is perpendicular to the longitudinal direction of the V-groove-shaped grindstone surface provided in parallel with the surface of the grindstone, and the center axis arrangement surface of the end face of each optical fiber is provided. The tape-shaped optical fiber core wire or the grindstone is slid in a direction perpendicular to the central axis arrangement surface of the optical fiber while the nearby edge portions are respectively in contact with the plurality of the V-groove-shaped grindstone surfaces, so that the central axis of each optical fiber is The method is characterized in that chamfering is performed on the edge of the end face near the arrangement surface.

In addition, as a grinding stone for treating an optical fiber end face used for polishing and chamfering the end face edge portion, V
By using one provided with at least one set of groove-shaped grindstone surfaces, it becomes possible to simultaneously perform polishing and chamfering at two edge portions on both sides of the end surface.

Further, a plurality of sets of the V-groove-shaped grindstone surfaces are provided.
Polishing of the edges of the end faces of a plurality of optical fibers of a tape-shaped optical fiber core by using ones arranged at the same pitch interval as the arrangement pitch of the tape-shaped optical fiber cores so that the grooves are parallel. The chamfering is performed in two directions, that is, one direction from the direction parallel to the optical fiber
This can be done using individual whetstones.

In addition, if a tapered portion extending outward is provided at the longitudinal end of the V-groove-shaped grindstone surface, the tip of the optical fiber can be easily mounted on the V-groove-shaped grindstone surface of the grindstone.

[0015]

1 (A) and 1 (B) are views showing the state of polishing and chamfering an end face edge portion in an optical fiber end face processing method according to the present invention, and FIG. 1 (A) is a perspective view thereof. FIG. 1B is a side view. FIGS. 3A and 3B
FIGS. 3A and 3B are views for explaining the processing of the terminal portion of the optical fiber ribbon, FIG. 3A is a perspective view thereof, and FIG. 3B is a side view thereof. FIG. 4A is a side view of the tape-shaped optical fiber core wire after the end face is chamfered as viewed from the end face side. 1, 3 and 4, reference numeral 1 denotes an optical fiber mainly composed of glass such as quartz, 2 denotes a coating made of an ultraviolet-curable resin or the like, 3 denotes a collective coating made of an ultraviolet-curable resin or the like, and 4 denotes a tape. Optical fiber ribbon.

First, as shown in FIG. 3 (A), at the end of the tape-shaped optical fiber 4, the collective coating 3 and the coating 2 on each optical fiber 1 are removed to expose the optical fiber 1. Let it. Next, while rotating the cutter 11 having a circular blade, the cutter 11 was moved in a direction perpendicular to the axis of the optical fiber,
A surface portion 1a on one side of the central axis arrangement plane XX 'of each optical fiber 1 and at a radial distance from the central axis arrangement plane in the vertical direction from the central axis arrangement plane is scratched. Thereafter, when a downward bending stress is applied to the optical fiber 1 so that the flaw 1a is on the outside, the optical fiber 1 is cleaved from the flaw 1a, and the optical fiber 1 is cut and substantially perpendicular to the central axis of the optical fiber 1. An end face is formed. At the same time, burrs 1b may remain at the edge of the end face opposite to the scratch 1a.

Since the flaw 1a is formed on one side of the central axis arrangement surface of each optical fiber 1 and is located at a radial portion of the optical fiber in a vertical direction from the central axis arrangement surface, the burr 1b
Can be formed on the surface portion which is on the opposite side of the central axis arrangement plane and which is at a radial distance from the optical fiber in the vertical direction from the central axis arrangement plane. The present invention has been made by paying attention to the fact that the flaw 1a and the burr 1b can be formed at a portion having a specific relationship with the central axis arrangement surface of the optical fiber.

Since the flaws 1a and burrs 1b of the plurality of optical fibers 1 are respectively arranged on a plane parallel to the plane X-X 'of the central axis, the surface of the base 6 of the grindstone 7 as shown in FIG. When the center of the optical fiber 1 is aligned with the V-groove-shaped grindstone surface 5 in the longitudinal direction of the V-groove and the tip of the optical fiber 1 is applied to the V-groove, a portion of the scratch 1a of each optical fiber 1 is formed. And burr 1b
All come into contact with the grindstone surface 5.

In this manner, when the tape-shaped optical fiber core wire 4 or the grindstone 7 is slid in the direction of the central axis arrangement surface, the edge portion 1c of each optical fiber 1 as shown in FIG. 1d is polished and chamfered. The edge portion of the end face of the optical fiber is brought into contact with the V-groove surface, and chamfering of about 10 μm is possible by reciprocating the sliding three times.
Further, the burrs 1b at the edge of the end face of the optical fiber 1 can be removed by this chamfering. If the burrs are eliminated, the end face of the optical fiber becomes only a plane substantially perpendicular to the central axis, so that PC coupling can be performed by abutting such two optical fibers.

Although the end face obtained by the cleavage is a plane substantially perpendicular to the central axis of the optical fiber, it may be strictly inclined about 1 to 2 degrees from the vertical plane. This tilt may affect the PC coupling, though not as much as with burrs.
On the other hand, since the energy of the transmitted light at the time of PC coupling is concentrated at the center of the optical fiber, the portion requiring complete contact between the glass surfaces at the time of PC coupling is only near the center of the optical fiber. Focusing on this, a more reliable end face processing method was considered. That is the method shown below.

FIG. 2 is a view showing an end face processing method according to the method. FIG. 2 (A) is a perspective view of the first step, FIG. 2 (B) is a side view of the first step, and FIG. FIG. 2D is a perspective view of the second step, and FIG. 2D is a side view of the second step. FIG. 4 (B)
FIG. 2 is a side view of the optical fiber ribbon after chamfering by this method, as viewed from the end face side. 2 and 4, the same reference numerals as those in FIG. 1 denote the same components.

In this method, a grindstone 10 having a plurality of V-groove-shaped grindstone surfaces 8 arranged in parallel on a base 9 is used, or a plurality of parallel V-grooves are formed by combining a plurality of blocks having oblique grindstone surfaces. A whetstone having a whetstone surface is used. In addition, the end of the tape-shaped optical fiber 4 is removed in the same manner as described above with reference to FIG. 3 to remove the coating 2 and the collective coating 3 to expose the optical fiber 1 and damage the surface of the optical fiber. Then, an end face is formed by cleavage.

Using this tape-shaped optical fiber 4,
In the first step, as shown in FIGS. 2A and 2B, the center axis arrangement surface of the optical fiber is aligned with the V-groove direction, and the tip end of each optical fiber 1 is formed with a plurality of V-groove-shaped grinding stone surfaces 8. The tape-shaped optical fiber core wire 4 is slid in the same direction as the central axis arrangement surface by contacting one groove, or the grindstone 10 is slid in the longitudinal direction of the V-groove, and the end face edge of the optical fiber 1 The part is polished and chamfered. The sliding may be unidirectional or reciprocating sliding. Then, the edge portions 1c and 1d of each optical fiber 1 shown in FIG. 4B are chamfered.

Next, in the second step, as shown in FIGS. 2C and 2D, the central axis arrangement surface of the optical fiber is made perpendicular to the V-groove direction, and the tip of each optical fiber 1 is placed in a plurality of V-grooves. The tape-shaped optical fiber core wire 4 is slid in the direction perpendicular to the central axis arrangement surface by contacting the respective grooves of the whetstone surface 8 with the respective grooves, or the whetstone 10 is slid in the longitudinal direction of the V groove. The edge of the end face of the optical fiber 1 is polished and chamfered. Also in this case, the sliding may be in one direction or reciprocating sliding. Then, the edge portions 1e and 1f of each optical fiber 1 shown in FIG. 4B are chamfered.

By chamfering the edge of the end face of the optical fiber 1 through the first step and the second step in this way, FIG.
As shown in (B), four edge portions 1c, 1d, 1
e and 1f are chamfered, and almost the entire periphery of the edge portion is chamfered. Note that only the square portion at the center of the end face is not chamfered, and the end face obtained by cleavage remains as it is. When the tip of the optical fiber is brought into contact with the V groove,
Since the optical fiber can bend slightly, the squares are not exact squares and each square may be rounded.

Further, even if the end face formed by cleavage is slightly inclined with respect to a plane perpendicular to the central axis of the optical fiber, this square portion is not chamfered in the case of FIG. Is smaller than the remaining end face
When PC coupling is performed by abutting the end faces of the optical fibers, a gap between the end faces of the optical fiber end faces is eliminated due to elastic deformation at the time of the abutting, and PC coupling is performed by a perfect glass contact surface.

In the above description, in the first step, the central axis arrangement surface of the optical fiber is set in the same direction as the longitudinal direction of the V groove, and in the second step, the central axis arrangement surface of the optical fiber is set in the longitudinal direction of the V groove. Although the description has been made by chamfering in a direction perpendicular to the above, the order of the first step and the second step may be reversed.

The following are specific examples of an optical fiber end face grinding wheel having a V-groove-shaped grinding wheel surface. FIG.
(A) The grindstone for treating an end face of an optical fiber has an inclined surface.
Wrapping film 13 on the diagonal surface of two blocks 12
And fix the fixing jig 14 so that the oblique surface has a V-groove shape.
Is fixed by Further, it is also possible to fix a plurality of sets of two blocks each having a V-groove-shaped grindstone surface, arranged so that the V-grooves are parallel to each other. The wrapping film 13 is formed by mixing abrasive grains of about 5 μm, such as diamond, silicon carbide, silicon oxide, alumina, and tungsten carbide, into a plastic and forming the film.

The grinding wheel for treating the end face of the optical fiber shown in FIG. 5B has a wrapping film 15 formed so as to have a plurality of V-grooves, which is attached to a base 16 provided with V-grooves. In addition, instead of the wrapping film,
Abrasive grains may be fixed directly on the grooved base by an adhesive or electrodeposition. It is also possible to place loose abrasive particles on a V-groove base and use it as a grindstone surface. When a plurality of V-grooves are provided in parallel, if the arrangement pitch interval is set to be the same as the arrangement pitch of the optical fibers of the tape-shaped optical fiber core wire, both the first step and the second step shown in FIG. It is desirable because it can be used.

The arrangement pitch interval of the optical fibers is often 250 μm between the central axes. Therefore, even if four V grooves are provided in parallel, the overall width is about 1 mm.
Therefore, it is difficult to make the tip of the optical fiber abut on such a fine V-groove-shaped grindstone surface. FIG. 6 (A)
(B) and (C) are examples in which a tapered portion extending outward is provided at the longitudinal end of the V-groove-shaped grindstone surface 15 in order to facilitate the work. 6A is a plan view, FIG. 6B is a side view, and FIG. 6C is a perspective view. The use of the tapered portion 17 makes it easy to insert the tip of the optical fiber into the V-groove.

After the end face treatment of the tape-shaped optical fiber core is performed by the method described above, the end portion of the tape-shaped optical fiber is inserted into the optical fiber insertion hole of the connector formed of resin or the like. By inserting and fixing the optical fiber with its tip slightly protruding, PC coupling can be performed by abutting against the end surface of another similar optical fiber without particularly polishing the end surface of the optical fiber.

[0032]

According to the method for treating an end face of an optical fiber of the present invention, the center of the optical fiber at the end face of each optical fiber of the tape-shaped optical fiber core is formed by using a grindstone having a V-groove-shaped grindstone surface. Since the edge portions far from the axis arrangement plane are chamfered at the same time, burrs formed at the same time by the cleavage are removed by the chamfering, so that only the chamfered end face can be used for PC bonding. Therefore, the polishing time can be shortened as compared with the entire polishing of the end face by the conventional technique, and it can contribute to cost reduction.

Further, using a grindstone having a plurality of V-groove-shaped grindstone surfaces arranged in parallel, the center axis arrangement surface of the optical fiber is aligned with the V-groove direction, and the tip of each optical fiber is brought into contact with one V-groove. Each optical fiber is slid by making the central axis arrangement surface of the optical fiber perpendicular to the V-groove direction and sliding the tip of each optical fiber into a separate V-groove-shaped grindstone surface. It is possible to chamfer the four-sided edge part of the end face, so that the remaining part as the cleavage end face becomes small. Therefore, even if the cleavage end face is slightly inclined from the vertical plane with respect to the optical fiber center axis, elastic deformation of the end face at the time of PC coupling So that better PC binding is achieved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a chamfering state of an end face edge portion in an embodiment of an optical fiber end face processing method of the present invention, wherein (A) is a perspective view and (B) is a side view.

FIGS. 2A and 2B are diagrams showing a chamfering state of an end face edge portion in another embodiment of the optical fiber end face processing method of the present invention, wherein FIG. 2A is a perspective view of a first step, and FIG. (C) is a perspective view of the second step, and (D) is a side view of the second step.

FIGS. 3A and 3B are views for explaining the processing of the terminal portion of the tape-shaped optical fiber, where FIG. 3A is a perspective view and FIG. 3B is a side view.

FIG. 4 is a view showing an end face of a tape-shaped optical fiber obtained by the method for treating an end face of an optical fiber of the present invention,
(A) is a side view of the end face obtained by the method of FIG. 1 as viewed from the end face side, and (B) is a side view of the end face obtained by the method of FIG. 2 as viewed from the end face side.

FIG. 5 is a view showing an embodiment of an optical fiber end surface processing grindstone of the present invention, wherein (A) is a side view of one example thereof, and (B).
FIG. 7 is a side view of another example.

FIG. 6 is a view showing another embodiment of the grindstone for treating an end face of an optical fiber of the present invention, wherein (A) is a plan view, (B) is a side view, and (C) is a perspective view.

FIGS. 7A and 7B are diagrams illustrating formation of an end face of an optical fiber by cleavage, in which FIG. 7A is a side view showing a state before cleavage, and FIG.
Is a side view showing a state after cleavage, and (C) is a side view showing a state after chamfering.

[Explanation of symbols]

 1: optical fiber 1a: scratch 1b: burr 1c, 1d, 1e, 1f: chamfered edge portion 2: coating 3: batch coating 4: tape-shaped optical fiber core wire 5, 8: grinding stone surface 6, 9, 16: Base 7, 10: Whetstone 11: Cutter 12: Block 13, 15: Wrapping film 14: Fixing jig

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiaki Kakii 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Sumitomo Electric Industries, Ltd. Yokohama Works

Claims (5)

[Claims] 1. An optical fiber having a coating of an optical fiber mainly composed of glass such as quartz as a main component is arranged in parallel, and a plurality of optical fibers are arranged in parallel. The fiber is exposed, and a surface portion on one side of the central axis arrangement surface of the optical fiber and at a radial distance from each of the optical fibers in a direction perpendicular to the central axis arrangement surface is scratched. A bending stress is applied to the optical fiber so that each optical fiber is cleaved and cut to form an end surface, and the central axis array surface of the optical fiber is aligned in the longitudinal direction of the V-groove-shaped grindstone surface provided on the surface of the grindstone. At the same time, the edge part of the end face of the optical fiber around the flaw and the edge part on the opposite side of the flaw are simultaneously brought into contact with the grindstone surface, and the tape-shaped optical fiber core wire or the grindstone is arranged in the central axis arrangement direction of the optical fiber. By sliding the optical fiber An edge treatment method for an optical fiber, comprising chamfering two edge portions of an end face of an optical fiber. 2. A tape-shaped optical fiber core having a plurality of coated optical fibers mainly composed of glass such as quartz and the like coated in parallel and provided with a collective coating on the outside thereof. The fiber is exposed, and a surface portion on one side of the central axis arrangement surface of the optical fiber and at a radial distance from each of the optical fibers in a direction perpendicular to the central axis arrangement surface is scratched. A bending stress is applied to the optical fiber so that each optical fiber is cleaved and cut to form an end face. Thereafter, the optical fiber is bent in the longitudinal direction of a plurality of V-groove-shaped grindstone surfaces provided in parallel with the surface of the grindstone. A tape-shaped optical fiber core is formed by aligning the central axis arrangement surfaces and simultaneously bringing the edge portion around the flaw of the end face of the optical fiber and the edge portion on the opposite side of the flaw into contact with one V-groove-shaped grindstone surface. Or grindstone with the center axis of the optical fiber And the center axis arrangement surface of the optical fiber is perpendicular to the longitudinal direction of the V-groove-shaped grindstone surface. By sliding the tape-shaped optical fiber core wire or the grindstone in a direction perpendicular to the central axis arrangement surface of the optical fiber while making contact with the V-groove-shaped grindstone surface,
An edge treatment method for an optical fiber, comprising chamfering four edge portions of each optical fiber. 3. A grinding stone for polishing an end face of an optical fiber, which comprises at least one set of V-groove-shaped grinding stone surfaces on the surface of the grinding stone. 4. The method according to claim 1, wherein a plurality of sets of the V-groove-shaped grindstone surfaces are arranged so that the V-grooves are parallel at the same pitch interval as the arrangement pitch of the tape-shaped optical fiber core wires to be subjected to the end face processing. The grindstone for treating an end face of an optical fiber according to claim 3. 5. The grindstone for treating an end face of an optical fiber according to claim 3, wherein a tapered portion extending outward is provided at an end in the longitudinal direction of the grindstone surface in a V-groove shape. .