JP2004093978A - Multiple optical fiber with hermetic sealing section and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To hermetically seal a metallized section of a multiple optical fiber to the through-holes of hermetic connecting components by using ordinary, furthermore fluxless solder without using special solder. <P>SOLUTION: The multiple optical fiber with a hermetic sealing section is provided with the multiple optical fiber 10 and the hermetic connecting components 20 made of metal. The components 20 have the overall length being the total length of a coating of a required length and both sides of the metallic coating section 12 of the fiber 10 and are formed with a first through-hole 21a having the length to cover at least a portion of the section 12 from its one end, a second through-hole 21b extending from the other end, and an uncovered section 22 therebetween. The boundary between the first through-hole 21a and the uncovered section 22 is formed as an inclined upward opening 24. Also, a soldering section 30 is provided for hermetically sealing the section 12 in the first through-hole 21a near the upward opening 24 to the components 20. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multi-core optical fiber with a hermetically sealed portion used for a parallel optical transmission module and a method for manufacturing the same.
[0002]
[Prior art]
In general, an optical module has a built-in optical element such as a waveguide or a light-emitting element, and internally couples the optical element with an optical fiber from outside. It is necessary to penetrate through the package wall of the module and introduce it into the interior. Furthermore, the package of the optical module needs to be hermetically sealed as a whole. It is an important factor that affects reliability.
[0003]
Further, a multi-core array of optical fibers is one of the indispensable component parts for a parallel optical transmission module in high-density transmission, such as connection with a planar waveguide and coupling with an array light emitting element. Even in the case of such a multi-core optical fiber array, that is, a multi-core optical fiber, hermetic sealing of a penetration portion that penetrates a package wall of a parallel optical transmission module is an important factor that affects reliability.
[0004]
In such a conventional hermetic sealing technique for a multi-core optical fiber, a part of the multi-core optical fiber is removed and metallized (metal coating is applied), and the metallized portion is directly soldered to a package. Although there is a method of tightly sealing, in this case, the strength when an external force is applied to the optical fiber in a portion that forms a boundary with the sealing portion, for example, outside the package, is uneasy, and is not practical.
[0005]
Therefore, conventionally, as shown in FIGS. 11 and 12, a metal pipe 220 is soldered to a metallized portion 212 of a multi-core optical fiber 210 and both are hermetically sealed, so that a multi-core with a hermetically sealed portion is provided. The optical fiber 201 is formed, and the metal pipe 220 of the multi-core optical fiber 201 with the hermetically sealed portion and the package of the parallel optical transmission module (not shown) are hermetically sealed. In this case, as the solder for sealing the multi-core optical fiber 210 and the metal pipe 220, a solder having a high melting point which is not affected by the temperature applied when the package is sealed is used.
[0006]
[Problems to be solved by the invention]
However, such a conventional multi-core optical fiber 201 with a hermetically sealed portion has the following problems. That is, in order to configure the multi-core optical fiber 201 with the hermetically sealed portion as shown in FIGS. 11 and 12, a multi-core optical fiber 201 having a cylindrical outer shape and a flat through hole 221 in the center is provided with a plurality of through holes. The solder must be inserted into the through hole 221 from the end face of the metal pipe 220 by inserting the metallized portion 212 of the core optical fiber 210.
[0007]
Therefore, in practice, the metallized portion 212 of the multi-core optical fiber 210 is soldered while heating the metal pipe 220 in a state where the metalized portion 212 is protruded from the end face of the metal pipe 220, while maintaining the heating so that the solder does not solidify. It is necessary to draw in the multi-core optical fiber 210 or the metal pipe 220 so that the metallization unit 212 is accommodated inside. In this case, since the multi-core optical fiber 210 is moved, the solder inserted therein may be biased, and as a result, a stable hermetic seal cannot be obtained in many cases.
[0008]
In order to solder the multi-core optical fiber 210 without moving it, the metallized portion 212 must be set near the end face of the metal pipe 220 and soldered at this position. In this case, the multi-core optical fiber 210 from the soldered portion to the outside of the metal pipe 220 is not protected by the metal pipe 220, so that the strength due to bending is extremely weak.
[0009]
Furthermore, it is possible to seal hermetically by injecting paste-like solder into the through-hole 221 of the metal pipe 220 and heating the multi-core optical fiber 210 after positioning it at a predetermined center position. In this case, since the paste-like solder usually contains a flux component, the flux must be removed after soldering. However, the flux remover may damage the coating of the multi-core optical fiber 210. Is not preferred.
[0010]
The object of the present invention is to eliminate the above-mentioned problems of the prior art, and to use a multi-core optical fiber by using ordinary and fluxless solder without using special solder such as paste solder or powder solder. It is an object of the present invention to provide a multi-core optical fiber having a hermetically sealed portion capable of hermetically sealing a metallized portion of the above in a through hole of a metal pipe (airtight connection component) and a method for manufacturing the same.
[0011]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and the invention according to claim 1 removes a coating of a portion apart from an end by a predetermined length in a multi-core optical fiber having a hermetically sealed portion used for a parallel optical transmission module. A multi-core optical fiber having a metal coating on the exposed portion; and a metal component having a through hole through which the multi-core optical fiber can be inserted, wherein the component is the metal coating of the multi-core optical fiber. Part and a length corresponding to a length obtained by adding a covering part of a required length to both sides thereof, and the through hole has a length covering at least a part of the metal coating part of the multi-core optical fiber from one end of the component. And a second through-hole extending from the other end of the component, and a non-cover portion having a required length that is opened in a non-cover state is formed in an intermediate portion between the first through-hole and the second through-hole. The boundary with the uncovered part is An airtight connection component formed at an upward opening inclined in a direction approaching the one end of the component; and brazing from the upward opening of the airtight connection component, the inside of the first through hole at least near the upward opening. And a brazing portion for hermetically sealing the metal coating portion to the hermetic connection component.
[0012]
According to a second aspect of the present invention, there is provided a multi-core optical fiber having a hermetically sealed portion used in a parallel optical transmission module, wherein a coating on a portion apart from an end portion is removed by a predetermined length and a metal coating is applied to the exposed portion. A multi-core optical fiber bundle in which a plurality of core optical fibers are vertically stacked or arranged side by side, and a metal component having a through hole through which the multi-core optical fiber bundle can be inserted, the component being a multi-core optical fiber The fiber coating has a total length corresponding to a length obtained by adding a coating portion of a required length to the metal coating portion and both sides thereof, and the through hole is formed from one end of the component to a metal coating portion of the multi-core optical fiber bundle. A first through-hole having a length covering at least a part thereof, and a second through-hole extending from the other end of the component are divided, and a non-cover portion having a required length opened in a non-cover state is formed therebetween. The first through hole and the lidless The boundary between the hermetic connection component formed in the upward opening inclined in the direction approaching the one end of the component, and brazing from the upward opening of the hermetic connection component, at least in the vicinity of the upward opening A multi-core optical fiber having a hermetically sealed portion, comprising: a brazing portion that collectively seals each of the metal coating portions of the multi-core optical fiber bundle in the first through hole to the hermetic connection component. .
[0013]
According to a third aspect of the present invention, in the first or second aspect of the invention, the first through-hole has a length covering one end of the hermetic connection component from the one end of the metal coating portion of the multi-core optical fiber. It is a multi-core optical fiber with a hermetically sealed portion.
[0014]
According to a fourth aspect of the present invention, in the first or the second aspect of the present invention, the brazing portion is hermetically sealed without using a flux using a thread solder in an inert gas atmosphere. It is a multi-core optical fiber with a stop.
[0015]
According to a fifth aspect of the present invention, a multi-core optical fiber in which a coating on a portion remote from the end is removed by a predetermined length and a metal coating is applied to the exposed portion is inserted into a through hole of the hermetic connection part to hermetically seal. A method of manufacturing a multi-core optical fiber having a hermetic sealing portion to be stopped; wherein the hermetically-sealed connection component has a total length corresponding to a length obtained by adding the metal coating portion of the multi-core optical fiber and a coating portion of a required length to both sides thereof; A first through hole having a length covering at least a part of the metal coating portion of the multi-core optical fiber from one end of the component, a second through hole extending from the other end of the component, Is formed in the middle thereof, and a lidless portion of a required length which is opened in a lidless state is formed in the middle thereof, and a boundary between the first through hole and the lidless portion is upwardly inclined in a direction approaching the one end of the component. Formed in the opening; The multi-core optical fiber is inserted through the first and second through holes of the connection component, and the metal coating portion is positioned substantially at the center of the hermetic connection component; the atmosphere around the hermetic connection component is inert. Substituting with a gas; heating the hermetic connection component and inserting solder into the upward opening to hermetically seal at least the metal coating portion in the first through hole near the upward opening to the hermetic connection component. A method for producing a multi-core optical fiber with a hermetically sealed portion.
[0016]
The invention according to claim 6 is the invention according to claim 5, wherein when the solder is inserted into the upward opening in the inert gas atmosphere, the periphery of the first through hole near the upward opening of the hermetic connection component is removed. This is a method for manufacturing a multi-core optical fiber with a hermetically sealed portion to be heated.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view of a main part showing an embodiment of a multi-core optical fiber with a hermetically sealed portion according to the present invention, and FIG. 2 is a front view thereof. , A multi-core optical fiber 10, a metal pipe (airtight connection part) 20, and a brazing part 30.
[0018]
As shown in FIG. 3, the multi-core optical fiber 10 is, for example, a four-core ribbon fiber in which four cores are formed in parallel, and a predetermined length of coating (covering portion 11) of a portion away from the end is removed. By applying a metal coating (Ni / Au) to the exposed portion, a metallized portion (metal coating portion) 12 having a predetermined length L is formed.
[0019]
As shown in FIGS. 4 and 5, the metal pipe (airtight connection part) 20 has a total length corresponding to about twice (2L) the length L of the metallized portion 12 of the multi-core optical fiber 10, and has an outer shape. It has a substantially cylindrical shape, and has a flat through hole 21 at the center thereof through which the multi-core optical fiber 10 can be inserted. When the metallized portion 12 of the inserted multi-core optical fiber 10 is located substantially at the center of the metal pipe (hermetic connection part) 20, the through hole 21 is provided at one end (left end in the figure) of the metal pipe (hermetic connection part) 20. And a second through-hole 21b extending from the other end (the right end in the figure) of the metal pipe (airtight connection part) 20 and having a length covering the main part of the metallized portion 12. A coverless portion 22 having a required length opened in a coverless state is formed in the middle, and at the boundary between the coverless portion 22 of the first through hole 21a and the one end (the left end in the figure) of the metal pipe (airtight connection component) 20. An upward opening 24 is formed on an inclined surface 23 inclined toward the approaching direction.
[0020]
As shown in FIG. 6, the brazing portion 30 is formed by soldering the metal pipe (airtight connection component) 20 from the upward opening 24 so that the metallized portion 12 in the first through hole 21 a at least in the vicinity of the upward opening 24 is metallized. This is to hermetically seal the pipe (airtight connection part) 20.
[0021]
Next, a method for manufacturing the multi-core optical fiber 1 with the hermetically sealed portion will be described. First, as shown in FIG. 3, a multi-core optical fiber 10 in which a metallized portion (metal coating portion) 12 having a predetermined length L is formed at a portion away from the end portion, and as shown in FIG. A metal pipe (airtight connection part) 20 having an upward opening 24 formed on an inclined surface 23 at the boundary between the lid 21 and the open part 22 is prepared.
[0022]
Next, the multi-core optical fiber 10 is inserted into the through-holes 21 (first through-hole 21a and second through-hole 21b) of the metal pipe (airtight connection component) 20, and as shown in FIG. The metal pipe (airtight connection part) 20 is positioned at a position substantially at the center.
[0023]
Next, the atmosphere around the metal pipe (airtight connection component) 20 is replaced with an inert gas (for example, nitrogen).
[0024]
In this inert gas (nitrogen) atmosphere, the periphery of the first through hole 21a close to the upward opening 24 of the metal pipe (airtight connection part) 20 extends around the entire circumference (360 °) of the metal pipe (airtight connection part) 20. Preferably, the outer peripheral surface of preferably １ ／ (180 °) or more is heated from both opposing directions and the thread solder is inserted into the lower part of the inclined surface 23 so that at least the upward opening 24 is formed as shown in FIG. The metallized portion 12 in the first through hole 21a in the vicinity is hermetically sealed with a metal pipe (hermetic connection component) 20.
[0025]
As a result, the metallized portion 12 of the multi-core optical fiber 10 and the metal pipe (hermetic connection component) 20 are hermetically sealed, and the covering portion 11a connected to the metallized portion 12 on the left side in the figure is a metal pipe ( Since it is arranged in the first through-hole 21a of the hermetic connection component) 20, it has sufficient strength against bending, and the covering portion 11b connected to the metallized portion 12 on the right side in the drawing is a metal pipe (airtight). Since it is arranged in the second through-hole 21b of the connection component) 20, it has sufficient strength against bending.
[0026]
When the solder is completely inserted, the heating is stopped and the solder is removed from the inert gas (nitrogen) atmosphere.
[0027]
The multi-core optical fiber 1 with the hermetically sealed portion manufactured in this manner is then used for the multi-core optical fiber 10 extending rightward in the figure from a metal pipe (hermetic connection part) 20, as shown in FIG. A required length of the coating on the distal end portion is removed, the exposed portion is adhered to the V-groove array 42, and the distal end of the multi-core optical fiber 10 is polished together with the V-groove array 42.
[0028]
Then, as shown in FIG. 8, a metal pipe (airtight connection part) 20 is arranged in the penetrating portion 41 of the package 40 of the parallel optical transmission module, and the multi-core optical fiber 10 is placed in a waveguide 43 provided in the package 40. After joining and bonding the tips, the metal pipe (hermetic connection component) 20 and the package 40 are hermetically sealed with metal (hermetic sealing portion 44) outside the package 40 and fixed. If necessary, the outer end of the metal pipe (airtight connection part) 20 and the covering portion 11a of the multi-core optical fiber 10 are fixed with an adhesive (adhesion fixing portion 45).
[0029]
Since the multi-core optical fiber 1 with the hermetically sealed portion is configured as described above, the metallized portion of the multi-core optical fiber 10 inserted through the through holes 21 (the first through hole 21a and the second through hole 21b). The soldering can be performed without moving the multi-core optical fiber 10 while the metal pipe 12 (airtight connection component) is substantially located at the center. Since the multi-core optical fiber 10 is not moved during soldering, stable soldering is possible.
[0030]
Further, it is possible to hermetically seal the metallized portion 12 of the multi-core optical fiber 10 and the metal pipe (hermetic connection component) 20 with a thread solder without using a special solder such as a paste solder or a powder solder. it can.
[0031]
Further, by heating the periphery of the first through-hole 21a near the upward opening 24 of the metal pipe (airtight connection component) 20 in an inert gas (nitrogen) atmosphere, thread solder is inserted under the inclined surface 23. It is possible to hermetically seal with fluxless solder without using flux. Therefore, there is no need to remove the flux after soldering, and there is no anxiety element such as corrosion due to the flux, and the material is suitable for hermetic sealing of the multi-core optical fiber 10 requiring reliability. In this case, an 80% Au / Sn solder having a melting point of 280 ° C. can be used as the high melting point fluxless solder.
[0032]
Furthermore, since the covering parts 11a and 11b connected to the metallized part 12 of the multicore optical fiber 10 on the left and right are disposed in the first through hole 21a and the second through hole 21b of the metal pipe (airtight connection part) 20, respectively. For example, the bonding step can be omitted as compared with the case where the covering portion 11a or 11b must be bonded and fixed to the metal pipe (airtight connection component) 20 using an appropriate adhesive (for example, an epoxy-based adhesive). Moreover, even if the covering portion 11a or 11b is not adhered and fixed to the metal pipe (airtight connection component) 20, sufficient strength against bending can be maintained.
[0033]
When a helium leak test was performed on the multi-core optical fiber 1 with the hermetically sealed portion manufactured according to the above manufacturing method, it was confirmed that the value was 1 × 10 ⁻¹⁰ Pa · m ³ / sec or less.
[0034]
FIG. 9 is a front view of a main part showing another embodiment of the multi-core optical fiber with a hermetically sealed portion according to the present invention, and FIG. 10 is a side view of the multi-core optical fiber 101 with the hermetically sealed portion. Means that a multi-core optical fiber 10 (for example, a four-core ribbon fiber in which four cores are formed in parallel) is vertically stacked in a plurality of stages (for example, two stages) and arranged in a plurality of rows (for example, two rows) on the left and right. (Four) multi-core optical fiber bundle 110 is handled.
[0035]
Therefore, the outer shape of the metal pipe (hermetic connection component) 120 has a shape obtained by dividing a cylinder into half and extending horizontally, and in the center thereof, a flat through hole 121 (through which the multi-core optical fiber bundle 110 can be inserted). It has a first through hole 121a and a second through hole 121b).
[0036]
The other parts are the same as those of the multi-core optical fiber 1 with the hermetically sealed portion shown in FIGS. 1 and 2, and the same parts are denoted by the same reference numerals as those used in FIGS. Description of each part is omitted. In the figure, reference numeral 125 denotes a flange required for performing a helium leak test.
[0037]
In the case of the multi-core optical fiber 101 with the hermetically sealed portion, when the brazing portion 30 is formed, the first pipe close to the upward opening 24 of the metal pipe (hermetic connection part) 120 in an inert gas (nitrogen) atmosphere. While heating the periphery of the through hole 121a from the outer peripheral surfaces of the upper and lower flat portions of the metal pipe (airtight connection component) 120, thread solder is inserted into the lower part of the inclined surface 23, so that at least the first portion near the upward opening 24 is formed. The metallized portion 112 in the through-hole 121a is hermetically sealed to a metal pipe (hermetic connection part) 120.
[0038]
The multi-core optical fiber 101 with the hermetic sealing portion can collectively and hermetically seal a plurality (for example, four) of the multi-core optical fibers 10 with one metal pipe (hermetic connection component) 120. For example, when the conventional metal pipes 220 as shown in FIGS. 11 and 12 are used, it is necessary to use a total of four pipes, one for each pipe. Naturally, interference between the pipes must be avoided. The package size becomes larger than necessary. In addition, since four places to be sealed with the package are required, it takes time to package the package. According to the multi-core optical fiber 101 with the hermetically sealed portion, a plurality of multi-core optical fibers 10 can be collectively air-tightly sealed to the metal pipe 120, so that these problems can be solved.
[0039]
In the above-described embodiment, a four-core ribbon fiber in which four cores are formed in parallel is exemplified as the multi-core optical fiber 10, but the present invention is not limited to this. For example, eight cores are formed in parallel. It is also possible to use an 8-core ribbon fiber or a 12-core ribbon fiber in which 12 cores are formed in parallel.
[0040]
In the above-described embodiment, the multi-core optical fiber bundle 110 is composed of four multi-core optical fibers 10 stacked in two stages vertically and arranged in two rows on the left and right. There is no limitation, for example, it may be one in which a plurality of rows are stacked vertically, or may be one in which a plurality of rows are arranged left and right, and the number of rows and the number of rows may be arbitrarily set as necessary. It is possible.
[0041]
Further, in the above-described embodiment, when the metallized portion 12 is located substantially at the center of the metal pipe (hermetic connection part) 20, the length of the first through-hole 21 a is adjusted to the length of the metal pipe (hermetic connection part) 20. A length covering one end (the left end in the figure) of the main part of the metallized portion 12, that is, a length covering half or more of the metallized portion 12 as shown in FIG. 5, is not limited to this. For example, a small length can be formed to have an arbitrary length from a length that covers only a part of the metallized portion 12 to a large size that can be formed to have a length that covers almost the entire metalized portion 12.
[0042]
Further, in the above embodiment, as shown in FIG. 4, the boundary between the second through-hole 21b and the non-covered portion 22 is formed by an inclined surface (boundary) inclined in a direction opposite to the inclined surface 23 on the first through-hole 21a side. Surface), but is not limited to this. In other words, what is required on the boundary surface on the second through-hole 21b side is that there is a required space between the inclined surface 23 on the first through-hole 21a side and the lower part of the inclined surface 23 in which the thread solder can be inserted. Since this is achieved, if this is achieved, it can be formed on an appropriate surface such as a vertical surface or a curved surface.
[0043]
Further, in the above-described embodiment, the bonding step using an adhesive is not required in forming the multi-core optical fibers 1 and 101 with the hermetically sealed portion. However, the present invention is not limited to this. For example, the metallized portion 12 (including a part of the covering portion 11b in some cases) exposed on the non-cover portion 22 is formed on a metal pipe (airtight connection part) using an appropriate adhesive (for example, an epoxy-based adhesive). It is also possible to adhere and fix to 20.
[0044]
Further, in the above-described embodiment, as shown in FIGS. 7 and 8, the coating of the distal end portion of the multicore optical fiber 10 extending rightward in the figure from the metal pipe (airtight connection part) 20 is removed by a required length. Then, this exposed portion was bonded to the V-groove array 42, and its tip was bonded and bonded to the waveguide 43, and the metal pipe (hermetic connection part) 20 and the package 40 were hermetically sealed and fixed with metal. However, the present invention is not limited to this. For example, the required length of the coating of the distal end of the multi-core optical fiber 10 extending from the metal pipe (airtight connection part) 20 to the left in the figure instead of the right in the figure is removed. Then, the exposed portion is adhered to the V-groove array 42, and its tip is connected and adhered to the waveguide 43, and the metal pipe (hermetic connection part) 20 and the package 40 are hermetically sealed and fixed with metal. It is also possible.
[0045]
【The invention's effect】
As described above, according to the present invention, in a multi-core optical fiber with a hermetically sealed portion used for a parallel optical transmission module, a coating at a portion apart from an end portion is removed by a predetermined length, and a metal coating is applied to the exposed portion. A metal part having a core optical fiber and a through-hole through which the multi-core optical fiber can be inserted, and the part includes a metal coating part of the multi-core optical fiber and a coating part of a required length on both sides thereof. A first through-hole having a length corresponding to at least a portion of the metal coating portion of the multi-core optical fiber from one end of the component, and a second through-hole having a length corresponding to the other end of the component. And a second through-hole extending from the first part, and a middle part having a required length opened in a state without a cover is formed therebetween, and a boundary between the first through-hole and the no-cover part approaches the one end of the component. Upward opening inclined in the direction By brazing the formed hermetic connection component and the upward opening of the hermetic connection component, at least the metal coating portion in the first through hole near the upward opening is hermetically sealed to the hermetic connection component. The metallized part of the multi-core optical fiber is made of airtight connection parts by using ordinary and fluxless solder without using special solder such as paste solder or powder solder. There is an effect that airtight sealing can be performed in the through hole.
[Brief description of the drawings]
FIG. 1 is a plan view of a main part showing an embodiment of a multi-core optical fiber with a hermetically sealed portion according to the present invention.
FIG. 2 is a front view of the multi-core optical fiber with a hermetically sealed portion in FIG. 1;
FIG. 3 is a front view (a) and a side view (b) of a multi-core optical fiber.
FIG. 4 is a front view (a) of a metal pipe (airtight connection part) and a cross-sectional view (b) taken along line IV-IV.
5A is a longitudinal sectional front view showing a state in which a multicore optical fiber is inserted into a metal pipe (airtight connection part), and FIG. 5B is a sectional view taken along line VV.
FIG. 6 is a longitudinal sectional front view (a) showing a state in which a metallized portion of a multi-core optical fiber and a metal pipe (hermetic connection component) are hermetically sealed, and a cross-sectional view (b) taken along the line VI-VI.
FIG. 7 is a longitudinal sectional front view showing a state in which a tip end of a multi-core optical fiber with a hermetically sealed portion is bonded to a V-groove array.
8 shows a state in which the tip of the multi-core optical fiber with a hermetically sealed portion of FIG. 7 is bonded and adhered to a waveguide, and a metal pipe (hermetic connection part) and a package are hermetically sealed and fixed with metal. It is a vertical front view of the principal part.
FIG. 9 is a front view of a main part showing another embodiment of the multi-core optical fiber with a hermetically sealed portion according to the present invention.
FIG. 10 is a side view of the multi-core optical fiber with a hermetically sealed portion in FIG. 9;
FIG. 11 is a plan view of a main part showing an example of a conventional multi-core optical fiber with a hermetically sealed portion.
FIG. 12 is a front view of the multi-core optical fiber with a hermetically sealed portion in FIG. 11;
[Explanation of symbols]
1, 101 Multi-core optical fiber with hermetic sealing portion 10 Multi-core optical fiber 11 Coating portion 12, 112 Metallized portion (metal coating portion)
20, 120 Metal pipes (airtight connection parts)
21a, 121a First through hole 21b, 121b Second through hole 22 No cover 23 Inclined surface 24 Upward opening 30 Brazing part 40 Package 41 Through part 42 V-groove array 43 Waveguide 44 Hermetic sealing part 45 Adhesive fixing part 110 Multi Core optical fiber bundle 125 flange

Claims (6)

In a multi-core optical fiber with a hermetically sealed portion used for a parallel optical transmission module,
A multi-core optical fiber in which a coating of a portion away from the end is removed by a predetermined length and a metal coating is applied to the exposed portion,
A metal part having a through hole through which the multi-core optical fiber can be inserted, wherein the part has a length obtained by adding the metal coating part of the multi-core optical fiber and a coating part of a required length to both sides thereof. A first through hole having a length corresponding to at least a part of the metal coating portion of the multi-core optical fiber from one end of the component, and a second through hole extending from the other end of the component. The first through-hole is divided into a through-hole, and a non-cover portion having a required length that is opened in a non-cover state is formed in the middle thereof. An airtight connection part formed in an inclined upward opening,
By brazing from the upward opening of the hermetic connection component, a brazing portion that hermetically seals the metal coating portion in the first through hole at least near the upward opening to the hermetic connection component,
A multi-core optical fiber with a hermetically sealed portion, comprising: In a multi-core optical fiber with a hermetically sealed portion used for a parallel optical transmission module,
A multi-core optical fiber bundle in which a plurality of multi-core optical fibers having a metal coating applied to the exposed portion by removing the coating of the portion away from the end by a predetermined length are vertically stacked or arranged side by side,
A metal component having a through hole through which the multi-core optical fiber bundle can be inserted, the component having a length obtained by adding a required length of the metal coating portion of the multi-core optical fiber bundle and coating portions on both sides thereof. A first through-hole having a length corresponding to at least a part of the metal coating portion of the multi-core optical fiber bundle from one end of the component, and And a second through hole extending therethrough, and a middle portion having a required length opened in an uncovered state is formed therebetween, and a boundary between the first through hole and the no cover portion approaches the one end of the component. An airtight connection part formed in an upward opening inclined in the direction of
By brazing from the upward opening of the hermetic connection component, the respective metal coating portions of the multi-core optical fiber bundle in the first through hole at least near the upward opening are hermetically sealed to the hermetic connection component at a time. Brazing part to stop,
A multi-core optical fiber with a hermetically sealed portion, comprising: The hermetic seal according to claim 1, wherein the first through hole has a length that covers a main part of a metal coating portion of the multi-core optical fiber from one end of the hermetic connection component. 4. Multi-core optical fiber with stop. The multi-core light with a hermetically sealed portion according to claim 1 or 2, wherein the brazing portion is hermetically sealed without using a flux by using a solder wire in an inert gas atmosphere. fiber. A multi-core optical fiber with a metal coating applied to the exposed portion by removing the coating of the portion away from the end by a predetermined length and inserting the multi-core optical fiber into the through hole of the hermetic connection component to hermetically seal the multi-core optical fiber. A method for manufacturing a core optical fiber;
The hermetic connection component has a total length corresponding to a length obtained by adding the metal coating portion of the multi-core optical fiber and a coating portion of a required length to both sides thereof, and the through-hole is a multi-core optical fiber from one end of the component. A required length that is divided into a first through-hole having a length covering at least a part of the metal coating portion of the optical fiber and a second through-hole extending from the other end of the component, and is opened in the middle without a cover. And a boundary between the first through hole and the non-cover portion is formed as an upward opening inclined in a direction approaching the one end of the component;
Inserting the multi-core optical fiber into the first and second through holes of the hermetic connection component, and positioning the metal coating portion substantially at the center of the hermetic connection component;
Replacing the atmosphere around the hermetic connection component with an inert gas;
Heating the hermetic connection component and inserting solder into the upward opening to hermetically seal at least the metal coating portion in the first through hole near the upward opening to the hermetic connection component;
A method for producing a multi-core optical fiber having a hermetically sealed portion, characterized by comprising: 6. The hermetic sealing part according to claim 5, wherein, when the solder is inserted into the upward opening in the inert gas atmosphere, the periphery of the first through hole near the upward opening of the hermetic connection component is heated. Of manufacturing a multi-core optical fiber with a core.

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