JP2017068052A - Manufacturing method of glass member with optical fiber, and glass member with optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a glass member with optical fiber which improves reliability without causing performance degradation.SOLUTION: A manufacturing method of a glass member with optical fiber 1 comprising an optical fiber 2 and a ferrule 3 (holding member) at least having a glass-made portion for holding the optical fiber 2 includes the steps of: fixing the optical fiber 2 to the ferrule 3 on a position for fixing the optical fiber 2; and forming a welding part 3a2 between the optical fiber 2 and the ferrule 3 by irradiating the ferrule 3 with a laser beam L to heat glass of the ferrule 3. A wavelength of the laser beam L is equal to a wavelength absorbed by OH-group contained in the glass.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for producing a glass member with an optical fiber and a glass member with an optical fiber.

  Conventionally, glass members with optical fibers have been used in the field of optical communications. For example, Patent Document 1 below discloses a fiber stub in which an optical fiber is fixed with an adhesive in a through-hole of a ferrule.

  In the fiber stub described in Patent Document 2, as described in paragraph [0043], the optical fiber and the ferrule are fused to each other by heating, so that the optical fiber is fixed in the ferrule.

JP-A-2005-241808 JP 2008-096843 A

  When the fiber stub of Patent Document 1 is used for a long time, the adhesive that has fixed the optical fiber may be deteriorated. For this reason, it has been difficult to improve reliability.

  On the other hand, in the fiber stub of Patent Document 2, since the optical fiber is heated and melted together with the ferrule, the performance of the optical fiber may be deteriorated.

  The objective of this invention is providing the manufacturing method of the glass member with an optical fiber which can improve reliability, and the glass member with an optical fiber which can raise reliability, without causing deterioration of a performance.

  The method for producing a glass member with an optical fiber according to the present invention is a method for producing a glass member with an optical fiber comprising an optical fiber and a holding member at least at which a portion for holding the optical fiber is made of glass, A step of arranging the optical fiber at a position where the optical fiber is fixed, and a step of irradiating the holding member with laser light to heat the glass of the holding member to form a welded portion made of the glass between the optical fiber and the holding member. The wavelength of the laser beam is a wavelength that is absorbed by the OH group contained in the glass.

  The wavelength of the laser beam is preferably 2.8 ± 0.1 μm.

  The holding member may be a ferrule, for example. In this case, it is preferable to form the welded portion by inserting an optical fiber into the through-hole of the ferrule and condensing and irradiating the inner wall of the through-hole of the ferrule.

  The glass member with an optical fiber of the present invention includes an optical fiber and a holding member in which at least a portion for holding the optical fiber is made of glass. The glass of the holding member has a β-OH value higher than that of the optical fiber, and the optical fiber and the holding member. An optical fiber is fixed by a weld portion made of the glass provided between the two.

  In the present invention, a part of the outer peripheral surface of the optical fiber may be fixed by the welded portion.

  The β-OH value of the glass is preferably 0.3 / cm or more and 33 / cm or less.

  The holding member may be a ferrule, for example. In this case, it is preferable that an optical fiber is inserted into the through hole of the ferrule, and a welded portion is provided between the through hole and the outer peripheral surface of the optical fiber.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the glass member with an optical fiber which can improve reliability, and the glass member with an optical fiber can be provided, without causing deterioration of a performance.

It is sectional drawing in alignment with the length direction of the glass member with an optical fiber which concerns on the 1st Embodiment of this invention. It is sectional drawing which follows the AA line in FIG. It is a cross-sectional view equivalent to FIG. 2 of the glass member with an optical fiber which concerns on the modification of the 1st Embodiment of this invention. It is an expanded sectional view in alignment with the length direction of an optical fiber for demonstrating the method to form the welding part in the 1st Embodiment of this invention. It is a cross-sectional view of the glass member with an optical fiber according to the second embodiment of the present invention. It is a top view of the glass member with an optical fiber concerning a 2nd embodiment of the present invention. It is a cross-sectional view of the glass member with an optical fiber according to the third embodiment of the present invention. It is a cross-sectional view of the glass member with an optical fiber which concerns on the modification of the 3rd Embodiment of this invention.

  Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Moreover, in each drawing, the member which has the substantially the same function may be referred with the same code | symbol.

(First embodiment)
FIG. 1 is a cross-sectional view taken along the length direction (Y direction) of the glass member with an optical fiber according to the first embodiment of the present invention. 2 is a cross-sectional view taken along the line AA in FIG. 1, and is a cross-sectional view taken along the X direction. Note that the X direction is a direction perpendicular to the Y direction. The glass member with an optical fiber 1 includes an optical fiber 2 extending in the Y direction and a ferrule 3 as a holding member for holding the optical fiber 2. In the present embodiment, the ferrule 3 is made of glass. The ferrule 3 has a through hole 3a extending in the Y direction. The optical fiber 2 is inserted into the through hole 3 a of the ferrule 3 and is held in the through hole 3 a of the ferrule 3.

  In the present embodiment, the optical fiber 2 is fixed by a welded portion 3 a 2 formed on the inner wall 3 a 1 of the through hole 3 a of the ferrule 3. In the present embodiment, the inner wall 3 a 1 of the through hole 3 a of the ferrule 3 is a part that holds the optical fiber 2. The welded portion 3a2 is formed by melting the glass constituting the ferrule 3. Accordingly, since the optical fiber 2 is fixed by the welded portion 3a2 made of glass, higher reliability can be obtained as compared with the case where the optical fiber 2 is fixed by an adhesive made of resin or the like. Further, since the optical fiber 2 is not substantially melted when the welded portion 3a2 is formed, the welded portion 3a2 can be formed without degrading the performance of the optical fiber 2. Therefore, it can be set as the glass member 1 with an optical fiber which has higher reliability.

  As shown in FIG. 1, in the present embodiment, the welded portion 3a2 is provided in a part of the length direction (Y direction) of the through hole 3a. In addition, as shown in FIG. 2, in the present embodiment, the welded portion 3 a 2 is formed continuously on the outer peripheral surface of the optical fiber 2. Therefore, the welding part 3a2 is formed so that the whole outer peripheral surface of the optical fiber 2 may be covered.

  As described above, the ferrule 3 of the present embodiment is made of glass. The glass constituting the ferrule 3 has a higher β-OH value than the material constituting the optical fiber 2. As the glass constituting the ferrule 3, for example, alkali-free glass, borosilicate glass, or the like is preferably used.

  In general, the material constituting the optical fiber 2 has an extremely low β-OH value in order to reduce transmission loss. The material is not particularly limited as long as it is a material having a β-OH value lower than that of the glass constituting the ferrule 3. As a preferable material constituting the optical fiber 2, quartz glass is exemplified. Quartz glass has a lower β-OH value than general glass. From the viewpoint of reducing the difference in thermal expansion coefficient between the optical fiber 2 and the ferrule 3, the ferrule 3 may be made of quartz glass having a β-OH value higher than that of the quartz glass constituting the optical fiber 2.

  FIG. 3 is a cross-sectional view corresponding to FIG. 2 of a glass member with an optical fiber according to a modification of the first embodiment of the present invention. As shown in FIG. 3, the welded portion 33 a 2 for fixing the optical fiber 2 is formed in a spot shape on the outer peripheral surface of the optical fiber 2. In this modification, welded portions 33a2 are formed at a total of four locations, two locations facing in the Z direction and two locations facing in the X direction. The Z direction is a direction perpendicular to the X direction and the Y direction. Moreover, the welding part 33a2 may be formed continuously in the Y direction, or may be formed discontinuously. When forming the welding part 33a2 discontinuously in the Y direction, the welding part 33a2 may be formed in a spot shape in the Y direction. Moreover, when forming the welding part 33a2 continuously in a Y direction, the welding part 33a2 may be formed so that it may extend linearly in a Y direction. For example, it may be formed so as to extend spirally along the outer peripheral surface of the optical fiber 2.

(Production method)
FIG. 4 is an enlarged cross-sectional view along the length direction of the optical fiber for explaining the method of forming the welded portion in the first embodiment. The manufacturing method of the glass member 1 with an optical fiber of this embodiment is as follows.

  The optical fiber 2 is inserted into the through hole 3 a of the ferrule 3. Next, the laser light L is condensed and irradiated on the portion of the inner wall 3a1 of the region where the weld 3a2 is formed in the ferrule 3. This laser beam L has a wavelength that is absorbed by the OH group contained in the glass constituting the ferrule 3. More specifically, the wavelength of the laser beam L is 2.8 μm. In addition, if the wavelength of the laser beam L is in the range of 2.8 ± 0.1 μm, it is sufficiently absorbed by the OH group.

  As described above, the β-OH value of the glass constituting the ferrule 3 is higher than the β-OH value of the material constituting the optical fiber 2. Therefore, the ferrule 3 becomes hotter than the optical fiber 2 when the laser beam L is irradiated. Thereby, only the ferrule 3 melt | dissolves and the welding part 3a2 is formed. The laser beam L is scanned and irradiated as necessary to form the welded portion 3a2. The positional relationship between the laser light L when irradiating the laser light L and the optical fiber 2 and the ferrule 3 may be adjusted by moving a light source (not shown) of the laser light L, or the optical fiber 2 and the ferrule 3. You may adjust by moving. Moreover, you may adjust by moving both a light source, the optical fiber 2, and the ferrule 3. FIG. The irradiation position of the laser beam L can be adjusted by rotating the optical fiber 2 and the ferrule 3 with the Y-direction axis as the rotation axis or by moving the optical fiber 2 and the ferrule 3 in the Y direction.

  As described above, the welded portion 3a2 is formed between the through hole 3a of the ferrule 3 and the optical fiber 2, and the optical fiber 2 is fixed in the through hole 3a of the ferrule 3 by the welded portion 3a2. The distance between the inner wall 3a1 of the through hole 3a of the ferrule 3 and the optical fiber 2 is preferably about 0.1 μm to 2 μm.

  The β-OH value of the material constituting the optical fiber 2 is preferably 0.3 / cm or less. When the β-OH value of the material constituting the optical fiber 2 is low, the temperature rise of the optical fiber 2 is reduced when the laser light L is irradiated. Therefore, the optical fiber 2 is not melted, and the welded portion 3a2 can be formed only from the glass constituting the ferrule 3. Therefore, the ferrule 3 can be welded to the optical fiber 2 without degrading the performance of the optical fiber 2.

  The β-OH value of the ferrule 3 is desirably 0.3 / cm or more and 33 / cm or less. Thereby, the inner wall 3a1 of the ferrule 3 can be easily melted by irradiation with the laser beam L. The β-OH value of the ferrule 3 is more preferably 1.0 / cm or more and 33 / cm or less. Thereby, the inner wall 3a1 of the ferrule 3 can be melted more easily.

Note that the β-OH value of the glass is measured as follows. Using FT-IR, the reference value of the transmittance of the glass (transmittance of light having a wave number of 3846 cm ⁻¹ ) and the transmittance of the absorption wavelength of the OH group (minimum transmittance of light having a wave number of around 3600 cm ⁻¹ ) Measure. When the transmittance of light of 3846 cm ⁻¹ is T ₁ %, the minimum transmittance of light having a wave number in the vicinity of 3600 cm ⁻¹ is T ₂ %, and the thickness of the glass is X mm, the β-OH value is expressed by the following formula 1. Can be sought.

β-OH value = (1 / X) log ₁₀ (T ₁ / T ₂ )... Formula 1

(Second Embodiment)
FIG. 5 is a cross-sectional view of a glass member with an optical fiber according to the second embodiment. FIG. 6 is a plan view of a glass member with an optical fiber according to the second embodiment of the present invention. The glass member 11 with an optical fiber of the present embodiment includes a holding member 13 having a plurality of groove portions 13a and an optical fiber 2 held in each groove portion 13a. The holding member 13 can be formed from the same material as the ferrule 3 of the first embodiment. The optical fiber 2 can also be formed from the same material as the optical fiber 2 of the first embodiment.

  The plurality of groove portions 13a of the holding member 13 are formed to extend in the Y direction. Further, the plurality of groove portions 13a are arranged in the X direction. As shown in FIG. 5, the cross section of the groove 13 a has a triangular shape. In addition, the shape of the cross section of the groove part 13a is not specifically limited, For example, the shape of polygon other than a triangle may be sufficient, or the shape which has a curved surface may be sufficient. The number of grooves 13a is not particularly limited.

  Each optical fiber 2 is held in each groove 13a. In the present embodiment, the wall surface of the groove 13 a is a portion that holds the optical fiber 2. The optical fiber 2 is fixed to the holding member 13 by a welded portion 13a2 formed on the wall surface of the groove portion 13a. As in the first embodiment, the welded portion 13a2 is formed by melting the glass constituting the holding member 13. Therefore, also in this embodiment, it can be set as the glass member 11 with an optical fiber which has high reliability.

  In the present embodiment, the upper portion of the optical fiber 2 in the Z direction protrudes outward from the groove 13a. However, the present invention is not limited to this, and the entire optical fiber 2 may be disposed so as to be embedded in the groove 13 a of the holding member 13.

  As in the manufacturing method of the first embodiment, the welding portion 13a2 in the present embodiment collects and irradiates the laser beam near the wall surface of the groove portion 13a in the region where the welding portion 13a2 is formed, thereby holding the holding member 13. Can be formed by melting the glass constituting the glass. Laser light may be emitted from the holding member 13 side or from the optical fiber 2 side.

(Third embodiment)
FIG. 7 is a cross-sectional view of a glass member with an optical fiber according to the third embodiment. The glass member 21 with an optical fiber includes a lid portion 24 provided on the holding member 13. The lid 24 can be formed from the same material as the holding member 13, for example. The glass member 21 with an optical fiber of the present embodiment has the same configuration as that of the second embodiment except that the lid portion 24 is provided.

  The lid portion 24 is provided with a plurality of groove portions 24a. Each optical fiber 2 is held in a space surrounded by the groove 13 a of the holding member 13 and the groove 24 a of the lid 24. A welding part 24a2 is formed in the groove part 24a of the lid part 24, and the optical fiber 2 is fixed by the welding part 24a2. In the present embodiment, this makes it possible to fix the optical fiber 2 more firmly. In addition, by having the lid portion 24, the optical fiber 2 is more difficult to break.

  The lid portion 24 may be welded to the holding member 13 or may be joined by an adhesive or the like. In addition, when the cover part 24 is welded or joined to the holding member 13 in this way, the cover part 24 may not have the welded part 24a2. Further, the lid 24 may not be made of the same material as that of the holding member 13.

  Moreover, when the cover part 24 has the welding part 24a2 like this embodiment, the cover part 24 does not necessarily need to be joined to the holding member 13.

  FIG. 8 is a cross-sectional view of a glass member with an optical fiber according to a modification of the third embodiment of the present invention. As shown in FIG. 8, the lid 44 may not have a groove. Further, as shown in FIG. 8, the lid 44 may be joined to the optical fiber 2 and the holding member 13 by an adhesive layer 45. Also in this case, the optical fiber 2 is fixed at the welded portion 13 a 2 by the holding member 13. Therefore, the reliability of the glass member 41 with an optical fiber can be improved.

  In each said embodiment, although the example in which the whole holding member was formed from glass was shown, this invention is not limited to this. In the present invention, at least the portion where the welded portion is formed, that is, at least the portion that holds the optical fiber may be formed from glass having a predetermined β-OH value, and the other portion is formed from another material. May be.

DESCRIPTION OF SYMBOLS 1 ... Glass member 2 with optical fiber ... Optical fiber 3 ... Ferrule 3a ... Through-hole 3a1 ... Inner wall 3a2 ... Welding part 11 ... Glass member with optical fiber 13 ... Holding member 13a ... Groove part 13a2 ... Welding part 21 ... Glass member 24 with optical fiber ... Cover part 24a ... groove 24a2 ... weld 33a2 ... weld 41 ... glass member 44 with optical fiber ... lid 45 ... adhesive layer

Claims (7)

A method for producing a glass member with an optical fiber comprising an optical fiber and a holding member comprising at least a portion for holding the optical fiber made of glass,
Arranging the optical fiber at a position where the optical fiber is fixed to the holding member;
Irradiating the holding member with laser light to heat the glass of the holding member to form the welded portion made of the glass between the optical fiber and the holding member,
The manufacturing method of the glass member with an optical fiber whose wavelength of the said laser beam is a wavelength absorbed by OH group contained in the said glass.   The manufacturing method of the glass member with an optical fiber of Claim 1 whose wavelength of the said laser beam is 2.8 +/- 0.1 micrometer.   The holding member is a ferrule, and the weld portion is formed by inserting the optical fiber into a through hole of the ferrule, and condensing and irradiating the laser beam on an inner wall of the through hole of the ferrule. Item 3. A method for producing a glass member with an optical fiber according to Item 1 or 2. With optical fiber,
A holding member made of glass, at least a portion holding the optical fiber,
The glass of the holding member has a higher β-OH value than the optical fiber,
A glass member with an optical fiber, wherein the optical fiber is fixed by a welding portion made of the glass provided between the optical fiber and the holding member.   The glass member with an optical fiber according to claim 4, wherein a part of an outer peripheral surface of the optical fiber is fixed by the welding portion.   The glass member with an optical fiber according to claim 4 or 5, wherein a β-OH value of the glass is 0.3 / cm or more and 33 / cm or less.   The holding member is a ferrule, the optical fiber is inserted into a through-hole of the ferrule, and the welded portion is provided between the through-hole and an outer peripheral surface of the optical fiber. The glass member with an optical fiber according to any one of the above.

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