JP4882786B2 - Bundle fiber manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a bundle fiber in which end faces of a plurality of optical fibers are bundled .

In recent years, optical fibers have been used in various applications such as optical communication and laser processing.
For example, the laser oscillation device 11 shown in the example of FIG. 6 includes a semiconductor laser array 10, a bundle fiber 20 in which a plurality of concentrating optical fibers 21 are bundled, lenses 31, 32, 35, a dichroic mirror 34, and a laser reflection. The member 33, the fiber laser optical fiber 40, the output laser optical fiber 50, and the output connector 60 are housed in a housing.
FIG. 6 also shows an enlarged view of the bundle fiber 20. In the upper diagram of FIG. 6, it seems that one condensing optical fiber 21 is opposed to the semiconductor laser array 10, but as shown in the enlarged view of the bundle fiber 20, A plurality of condensing optical fibers 21 are opposed to each other.

In the example of FIG. 6, the semiconductor laser array 10 includes a plurality of light emitting units that emit semiconductor laser light arranged in the X-axis direction. Then, the incident surface of each condensing optical fiber 21 is fixed by a fixing member 23 at a position facing each light emitting portion, and each light emitting portion (one semiconductor laser array 10 in the example of FIG. The semiconductor laser light emitted from each light-emitting section is guided to each condensing optical fiber 21. The exit-side end face of the condensing optical fiber 21 is bundled by a sleeve 22, and the guided semiconductor laser light is emitted from the bundled emission face.
The semiconductor laser light emitted from the emission surface bundled by the sleeve 22 is converted into parallel light by the lens 31, and further passes through a dichroic mirror 34 that transmits light having the wavelength of the semiconductor laser light. And is incident from the incident surface of the optical fiber 40 for fiber laser. The optical fiber 40 for a fiber laser has a core doped with a rare earth such as Nd (neodymium), generates fiber laser light by using incident semiconductor laser light as excitation light, and emits fiber laser light from both end faces. To do. In the example of FIG. 6, a laser reflecting member 33 (concave mirror or the like) is disposed at a position facing one end surface, and fiber laser light is extracted from only one end surface.
The fiber laser light emitted from the fiber laser optical fiber 40 is converted into parallel light by the lens 32 and reflected by the dichroic mirror 34 that reflects light having the wavelength of the fiber laser light. The reflected fiber laser light is collected by the lens 35 and is incident on the incident surface of the output laser optical fiber 50. The output laser optical fiber 50 guides the incident fiber laser light to the output connector 60.

In the laser oscillation device 11 shown in the example of FIG. 6, the general optical fiber 21 shown in the example of FIG. 5 is used as the concentrating optical fiber 21. The optical fiber 21 has a core member C1 that guides light incident from the end face, and covers the periphery of the core member C1 and transmits light incident on the core member C1 at a lower refractive index than the core member C1. The clad member C2 is confined inside, and the clad member C3 is covered with a covering member C3 that covers the periphery of the clad member C2 and protects the clad member C2 and the core member C1. In a general optical fiber, a resin member is used for the covering member C3.
There are various optical fiber diameters. In the concentrating optical fiber 21 in the laser oscillation device 11 in FIG. 6, the diameter K1 of the core member C1 in FIG. Is about 150 [μm], the diameter K2 of the cladding member C2 is about 165 [μm], and the diameter K3 of the covering member C3 is about 300 to 400 [μm].
When the bundle fiber 20 is configured using the general optical fiber 21 as described above, the covering member C3 may be melted by the amount of heat generated in the sleeve 22 where the semiconductor laser light is concentrated.

Regarding the bundle fiber, for example, in the prior art described in Patent Document 1, a plurality of optical fibers having high heat resistance having a metal coating are inserted into a sleeve such as stainless steel having high heat resistance without removing the metal coating. A bundle light guide with high heat resistance, which is fixed inside with a heat resistant adhesive, has been proposed.
JP 2003-161849 A

In the prior art described in Patent Document 1, accurate positioning is required so that the end faces of a plurality of optical fibers accommodated in the sleeve are arranged on the same plane orthogonal to the central axis of the sleeve. It takes time and effort.
The present invention, such has been invented in view of, in the case of bundling the end face of the optical fiber by using a sleeve, bundle fiber the end face of the optical fiber, can be easily positioned on the same plane It is an object to provide a manufacturing method .

As means for solving the above-mentioned problems, a first invention of the present invention is a method for manufacturing a bundle fiber as described in claim 1.
The bundle fiber manufacturing method according to claim 1, wherein a core member that guides incident light in a longitudinal direction, covers the periphery of the core member, and emits the light at a lower refractive index than the core member. A plurality of optical fibers composed of a clad member confined in the core member, a sleeve having an inner diameter through which the plurality of optical fibers can be bundled and inserted, and a CO ₂ laser oscillation device are used.
Then, a plurality of the optical fibers are inserted into the sleeve, and the sleeve and the optical fiber inserted into the sleeve are melted and cut simultaneously with the CO ₂ laser light emitted from the CO ₂ laser oscillation device, and then cut. When the surface and the optical fiber are melt-bonded and fixed on a surface, an optical fiber including a covering member that covers the periphery of the clad member is used, and the covering of at least the insertion portion of the optical fiber into the sleeve is used. to form a coating-removing portion removing the member, so that the coating-removing portion is located inside the sleeve, inserting the plurality of the optical fiber in the sleeve, CO ₂ emitted from the CO ₂ laser oscillator Using laser light, the sleeve and the coating removal portion of the optical fiber inserted into the sleeve are melted and cut at the same time. And said optical fiber is a manufacturing method of fixing by fusion bonding with.

The bundle fiber manufacturing method described in the present embodiment is a manufacturing method in which the core member, the clad member, and the sleeve are made of a quartz-based material.

Further, in the bundle fiber manufacturing method described in the present embodiment, in the sleeve, a plurality of inserted optical fibers are fixed with the adhesive using a silica-based inorganic adhesive. And then cutting with the CO ₂ laser oscillation device.

A second invention of the present invention is a method for manufacturing a bundle fiber as described in claim 2 .
The bundle fiber manufacturing method according to claim 2 , wherein a core member that guides incident light in a longitudinal direction, a periphery of the core member, and a lower refractive index than the core member A plurality of optical fibers composed of a clad member confined in the core member, a sleeve having an inner diameter through which the plurality of optical fibers can be bundled and inserted, and a CO ₂ laser oscillation device are used.
Then, a plurality of the optical fibers are inserted into the sleeve, and the sleeve and the optical fiber inserted into the sleeve are melted and cut simultaneously with the CO ₂ laser light emitted from the CO ₂ laser oscillation device , and then cut. when fixing by melting bonding the optical fiber and the sleeve at the surface, the cutting surface by the CO ₂ laser beam, so that the plane perpendicular to the central axis of the sleeve, of the CO ₂ laser beam When viewed from a cutting direction orthogonal to both the optical axis and the central axis, the direction of the optical axis and the central axis are not orthogonal to each other, and the central axis is not the CO ₂ laser light emitting portion. It is a manufacturing method which cut | disconnects so that the state inclined to the side at the predetermined angle may be maintained.

The third invention of the present invention is a method for manufacturing a bundle fiber as described in claim 3 .
The bundle fiber manufacturing method according to claim 3 is the bundle fiber manufacturing method according to claim 2 , wherein the CO ₂ laser oscillation device and a plurality of the fiber fibers are arranged so that the optical axis and the central axis intersect. In the manufacturing method, the sleeve into which the optical fiber is inserted is positioned, and the sleeve and the optical fiber are reciprocally rotated around the central axis while maintaining the inclined state.

The fourth invention of the present invention is a method for manufacturing a bundle fiber as described in claim 4 .
The bundle fiber manufacturing method according to claim 4 is the bundle fiber manufacturing method according to claim 2, wherein the central axis crosses the optical axis while maintaining the inclined state. In the manufacturing method, the sleeve and the optical fiber are moved relative to the laser beam in the cutting direction.

The fifth invention of the present invention is a method for manufacturing a bundle fiber as described in claim 5 .
The bundle fiber manufacturing method according to claim 5 is the bundle fiber manufacturing method according to claim 2 , wherein the sleeve and the optical fiber are reciprocally rotated around the central axis while maintaining the inclined state. And the sleeve and the optical fiber are moved relative to the laser beam in the cutting direction so that the central axis crosses the optical axis.

Further, the bundle fiber described in the present embodiment is a bundle fiber in which at least one end face of a plurality of optical fibers is bundled using the above-described bundle fiber manufacturing method.

If the manufacturing method of the bundle fiber of Claim 1 is used, a some optical fiber will be inserted in a sleeve, a sleeve and an optical fiber will be melt-cut simultaneously, and a bundle end surface will be formed in a cut surface. For this reason, it is not necessary to position the optical fibers one by one so that the end faces of the plurality of optical fibers are on the same plane. In addition, by using CO ₂ laser light that is easily absorbed by the optical fiber, the sleeve and the optical fiber can be melted and cut at the same time, and the sleeve and the optical fiber can be fused and fixed on the cut surface. is there.

In the manufacturing method of the bundle fiber as claimed in claim 1, it is possible to protect the optical fiber at the covering member.
CO ₂ laser light can also cut a covering member (for example, a resin-made covering member), and particularly when the covering member is formed of a transparent resin material, the CO ₂ laser light is well absorbed and cut more easily. can do.

Moreover, in the manufacturing method of the bundle fiber of Claim 1 , a bundle diameter can be made smaller by removing a coating | coated member. Further, in a sleeve where incident light (semiconductor laser light, etc.) concentrates, damage to a covering member (for example, a resin-made covering member) that is relatively weak against heat can be prevented (even if the power density is high) Can prevent damage to the components).

Further, in the bundle fiber manufacturing method described in the present embodiment , the sleeve and the optical fiber are made of the same quartz material, so that they can be easily melted at the same time and can be more easily melt-bonded.

In the bundle fiber manufacturing method described in the present embodiment, the sleeve and the optical fiber are bonded with an adhesive based on silica-based silica (SiO ₂ ) before being melt-cut with CO ₂ laser light. The gap between the optical fibers can be filled with an adhesive, and the melting can be made more uniform. Moreover, the position shift of the optical fiber with respect to the sleeve at the time of melt cutting can be prevented.

Further, if the method for manufacturing a bundle fiber according to claim 2 is used, the portion of the cut surface where the CO ₂ laser beam hits first in time (the side closer to the emission portion of the CO ₂ laser) has a larger amount of melting, and the time Therefore, the slope of the cut surface due to the smaller amount of melting in the portion that hits later (the side farther from the emission portion of the CO ₂ laser) (the slope of the angle β with respect to the ideal cut surface Mt perpendicular to the central axis of the sleeve (see FIG. 1) )) Can be suppressed.

Moreover, if the manufacturing method of the bundle fiber of Claim 3 is used, the flatness of a cut surface can be made more uniform. Moreover, the optical fiber can be prevented from being damaged by reciprocating rotation.

Moreover, if the bundle fiber manufacturing method according to claim 4 is used , the flatness of the cut surface can be made more uniform without being affected by the power density distribution of the CO ₂ laser beam.

Moreover, if the manufacturing method of the bundle fiber of Claim 5 is used, the flatness of a cut surface can be made further uniform.

Further, in the bundle fiber described in the present embodiment, a bundle fiber in which end surfaces of a plurality of optical fibers are positioned on the same plane can be easily realized.

The best mode for carrying out the present invention will be described below with reference to the drawings. Hereinafter, the “optical fiber 21” is not limited to the concentrating optical fiber 21 shown in FIG.
FIG. 1 shows an embodiment of a method for manufacturing a bundle fiber of the present invention.
First, in the optical fiber 21 having the structure shown in FIG. 5, the covering member C <b> 3 that is inserted through the sleeve 22 is removed to form a covering removal portion RM. For example, the covering member C3 is dissolved and removed with a solvent or the like.
Next, the optical fiber 21 is inserted into the sleeve 22 so that the coating removal portion RM is positioned inside the sleeve 22. Then, the CO ₂ laser light LC is irradiated from a direction substantially orthogonal to the central axis ZS of the sleeve 22 to cut the sleeve 22 and the coating removal portion RM of the optical fiber 21 simultaneously. At this time, the ideal cut surface Mt is a surface orthogonal to the central axis ZS.
Since the CO ₂ laser has a characteristic that it is easily absorbed by a transparent material such as glass (easy to be heated), if the sleeve 22 is made of a transparent material (the coating removal portion RM of the optical fiber 21 includes the cladding member C2 and the core member). C1, which is generally a transparent material) and can be more easily cut (melt cut).

Since the cutting by the CO ₂ laser beam is a cutting in which the irradiated material is heated and melted, the material of the clad member C2 and the core member C1 of the optical fiber 21 and the material of the sleeve 22 are made the same material, and the melting temperatures thereof are set. By making it close, it can melt | dissolve more uniformly and can cut | disconnect.
Further, since the melted portion is solidified and bonded (fixed) after cutting, it is easier to bond by using the same material. For example, a quartz-based material is generally used for the core member C1 and the clad member C2 because of the refractive index. Therefore, if the sleeve 22 is also made of a quartz material, it is easy to make the clad member C2, the core member C1, and the sleeve 22 the same material.
The optical fiber 21 may be fixed in the sleeve 22 with an inorganic adhesive based on silica (SiO ₂ ) and then cut with a CO ₂ laser. In this case, since the gap between the optical fibers 21 is filled with the heat-resistant adhesive, more uniform melting is possible.

Here, in the fusion cutting by the CO ₂ laser beam LC, the outer wall of the front sleeve 22, the front side coating removal part RM inside the sleeve 22, the far side coating removal part RM, and the outer wall of the far side sleeve 22 are called. Melting proceeds in sequence. For this reason, the melting distance in the direction parallel to the central axis ZS differs depending on the time difference until the outer wall of the sleeve 22 far from the outer wall of the sleeve 22 on the near side is melted, and the actual cutting surface M is the ideal cutting surface. The surface is inclined by an angle β with respect to the surface Mt (a plane orthogonal to the central axis ZS) (in FIG. 1, the angle β is greatly illustrated for easy understanding).

Therefore, as shown in FIGS. 2 and 3, a cutting direction (see FIG. 2) orthogonal to both the optical axis of the CO ₂ laser beam LC and the central axis of the sleeve 22 (in the case of FIGS. 2 and 3, the rotational axis ZS3). 3 (corresponding to the X-axis direction in FIG. 3), the central axis is kept inclined by a predetermined angle β on the side of the emission part of the CO ₂ laser light LC with respect to the direction orthogonal to the optical axis. In this way, the sleeve 22 and the coating removal part RM are cut. Thereby, the actual cut surface M can be brought closer to the ideal cut surface Mt. 2 and 3, the X axis, the Y axis, and the Z axis are orthogonal to each other, the Y axis indicates the vertical direction, and the X axis and the Z axis indicate the horizontal direction. Note that 22α indicates the other of the cut sleeve 22.
For example, the CO ₂ laser beam LC emitted from the laser emission unit NC is arranged in the vertical direction (Y-axis direction). Then, a cutting device including a linear stage S2 that reciprocates in the X-axis direction on the base S1 fixed to a horizontal plane and a rotary stage S3 that reciprocally rotates on the linear stage S2 is used. The rotation axis ZS3 of the rotation stage S3 has an angle β with respect to the horizontal plane. Note that the rotation axis ZS3 and the X axis are orthogonal to each other.

Next, an example of a work flow of the method for manufacturing the bundle fiber 20 described in the present embodiment will be described with reference to FIG.
First, in step S10, the sleeve 22 into which the coating removal portions RM of the plurality of optical fibers 21 are inserted is inserted and fixed to the rotary stage S3 on the linear stage S2, and the central axis of the sleeve 22 coincides with the rotary axis ZS3. Then, the sleeve 22 and the bundle fiber 20 are attached (installed) to the rotary stage S3 on the linear stage S2.
Next, in step S20, the rotary stage S3 is driven to rotate the sleeve 22 back and forth around the rotation axis ZS3.
In step S30, the linear stage S2 is driven to swing the sleeve 22 reciprocating around the rotation axis ZS3 to the left and right (reciprocating) along the X-axis direction.
In step S40, the CO ₂ laser beam LC is continuously irradiated for a certain period of time, and the sleeve 22 and the coating removal portion RM of the optical fiber 21 inserted into the sleeve 22 are melted and cut.
Thereafter, in step S50, the linear stage S2 is stopped. In step S60, the rotary stage S3 is stopped. In step S70, the sleeve 22 is removed from the rotary stage S3 on the linear stage S2.
Thus, in the reciprocating rotation, the optical fiber 21 is prevented from being damaged by twisting, and the flatness of the cut surface is made more uniform without being affected by the power density distribution of the CO ₂ laser light LC in the reciprocating rotation and reciprocating movement. can do.

In the above description, while reciprocally rotating the sleeve 22 by the rotation stage S3, although is reciprocated by the linear stage S2, only reciprocating rotation by the rotation stage S3, or performs only reciprocating movement by linear stage S2, CO ₂ You may cut | disconnect so that laser beam LC may be irradiated for a fixed time. When only reciprocating rotation by the rotary stage S3 is performed, the sleeve 22 is arranged so that the optical axis of the CO ₂ laser beam LC and the rotation axis ZS3 intersect.
Instead of rotating and moving the sleeve 22, the laser emitting part NC may be rotated and moved around the sleeve 22, and the sleeve 22 is rotated and moved relative to the CO ₂ laser light LC. do it.
If the bundle fiber 20 is manufactured using the bundle fiber manufacturing method described above, the end faces of the optical fibers can be more easily positioned on the same plane. Moreover, cutting and melt bonding can be performed in a shorter time.
Further, when the cut surface M is further polished, the sleeve 22 and the core member C1 and the clad member C2 of the optical fiber can be uniformly polished by using the same quartz-based material.

Further, as another effect, in the bundle fiber manufacturing method in the present embodiment, the covering member C3 of the optical fiber 21 is removed and bundled, and therefore the diameter of each optical fiber 21 at the bundled end surface (cut surface M). Is smaller, and the diameter of the end surface (cut surface M) can be further reduced.
For example, as shown in FIG. 4, when light emitted from the left optical fiber with a diameter d1 and a spread angle θ1 enters the right optical fiber with a diameter d2 and a spread angle θ2, d1 × θ1≈d2 The relationship of xθ2 is established. Since the incident angle θ2 has an upper limit, it is effective to make the exit side diameter d1 smaller in order to make the diameter d2 as small as possible.

The bundle fiber manufacturing method of the present invention is not limited to the appearance and configuration of the bundle fiber 20 described in the present embodiment, the manufacturing method described in FIGS. 1 to 3, and the like, and does not change the gist of the present invention. Various changes, additions and deletions can be made within the range.
The bundle fiber manufacturing method described in the present embodiment can be applied to the manufacture of various bundle fibers in addition to the bundle fiber 20 used in the laser oscillation device 11 shown in the example of FIG. .
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.
In the present embodiment, the optical fiber 21 provided with the covering member C3 that prevents damage to the clad member C2 has been described as an example. However, an optical fiber that does not include the covering member C3 may be used. In that case, it is not necessary to form the coating removal part RM.

It is a figure explaining one Embodiment of the manufacturing method of the bundle fiber 20 of this invention. 6 is a diagram illustrating an example of a manufacturing method for making a cut surface by a CO ₂ laser beam LC a surface orthogonal to the central axis (rotation axis ZS3) of a sleeve 22. FIG. 6 is a diagram illustrating an example of a manufacturing method for making a cut surface by a CO ₂ laser beam LC a surface orthogonal to the central axis (rotation axis ZS3) of a sleeve 22. FIG. It is a figure explaining the relationship between the diameter d1 at the time of emitting light and the spread angle θ1, and the diameter d2 and the spread angle θ2 (incident angle θ2) at the time of incident light that collects and enters the light. It is a figure explaining the structure of the optical fiber. It is a figure explaining the example using the bundle fiber 20 (in this case, the laser oscillation apparatus 11). It is a figure explaining the example of the work flow of the manufacturing method of the bundle fiber 20 demonstrated in this Embodiment.

DESCRIPTION OF SYMBOLS 10 Semiconductor laser array 11 Laser oscillator 20 Bundle fiber 21 Optical fiber (Condensing optical fiber)
22 Sleeve 23 Fixing member 31, 32, 35 Lens 33 Laser reflecting member 34 Dichroic mirror 40 Optical fiber for fiber laser 50 Optical fiber for output laser 60 Output connector C1 Core member C2 Clad member C3 Cover member LC CO ₂ Laser light M Cut surface Mt ideal cut surface RM coating removal part

Claims (5)

A plurality of core members configured to guide incident light in a longitudinal direction and a clad member that covers the periphery of the core member and confines the light in the core member at a lower refractive index than the core member. Optical fiber,
A sleeve having an inner diameter through which a plurality of optical fibers can be bundled and inserted;
Using a CO ₂ laser oscillator,
Inserting a plurality of the optical fibers into the sleeve;
The sleeve and the optical fiber inserted into the sleeve are melted and cut simultaneously with CO ₂ laser light emitted from the CO ₂ laser oscillation device, and the sleeve and the optical fiber are melted and joined at a cut surface. when fixing Te,
Using an optical fiber provided with a covering member covering the periphery of the cladding member,
Forming a coating removal portion from which the coating member of at least the insertion portion of the optical fiber into the sleeve is removed;
A plurality of the optical fibers are inserted through the sleeve such that the sheath removing portion is located inside the sleeve;
The sleeve and the coating removal portion of the optical fiber inserted into the sleeve are melted and cut simultaneously by CO ₂ laser light emitted from the CO ₂ laser oscillation device , and the sleeve and the optical fiber are cut at the cut surface. A method for manufacturing a bundle fiber , in which and are fused and fixed . A plurality of core members configured to guide incident light in a longitudinal direction and a clad member that covers the periphery of the core member and confines the light in the core member at a lower refractive index than the core member. Optical fiber,
A sleeve having an inner diameter through which a plurality of optical fibers can be bundled and inserted;
Using a CO ₂ laser oscillator,
Inserting a plurality of the optical fibers into the sleeve;
The sleeve and the optical fiber inserted into the sleeve are melted and cut simultaneously with CO ₂ laser light emitted from the CO ₂ laser oscillation device , and the sleeve and the optical fiber are melted and joined at a cut surface. When fixing
The cut surface by the CO ₂ laser light is a plane perpendicular to the central axis of the sleeve,
When viewed from a cutting direction orthogonal to both the optical axis and the central axis of the CO ₂ laser light, the central axis is not the direction in which the optical axis direction and the central axis are orthogonal, but the central axis is the CO _2. A method for manufacturing a bundle fiber, which is cut while maintaining a state inclined at a predetermined angle toward a laser beam emitting portion. A bundle fiber manufacturing method according to claim 2 ,
Positioning the CO ₂ laser oscillation device and the sleeve through which the plurality of optical fibers are inserted so that the optical axis and the central axis intersect,
A method for manufacturing a bundle fiber, in which the sleeve and the optical fiber are reciprocally rotated around the central axis while the inclined state is maintained. A bundle fiber manufacturing method according to claim 2 ,
The bundle fiber is cut by moving the sleeve and the optical fiber relative to the laser light in the cutting direction so that the central axis crosses the optical axis while maintaining the inclined state. Production method. A bundle fiber manufacturing method according to claim 2 ,
While maintaining the tilted state, the sleeve and the optical fiber are reciprocally rotated around the central axis, and the sleeve and the light with respect to the laser beam so that the central axis crosses the optical axis. A bundle fiber manufacturing method for cutting a fiber by moving the fiber relatively in the cutting direction.

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