JP2007264424A - Optical fiber component and optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber component having less optical axis deviation and having thermal resistance. <P>SOLUTION: Disclosed is an optical fiber component in which at least one end of an optical fiber is fixed in the bore of a tubular body. When, in a cross sectional view in a direction orthogonal to the axial direction of the tubular body, the inner face of the tubular body is equally divided into n regions (n is an integer ≥3) in the circumferential direction, the one end of the optical fiber is provided, in each of the n regions, with a contact part that comes into partial contact with the inner circumferential face of the tubular body. The optical fiber and the tubular body are joined by means of a joining material present in non-contact parts. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical fiber component and an optical device using the optical fiber component.

In recent years, optical fiber sensors that detect physical quantities such as temperature using optical fibers and optical fiber communication have been widely used.
For example, an optical fiber sensor is advantageous in that it does not require power supply to the sensing unit, is advantageous for remote measurement, and enables multipoint measurement using multiplexing technology. Widely used in fields such as structures, submarine seismometers, and manufacturing process lines.
Further, an optical fiber sensor using an optical fiber made of fused silica having excellent heat resistance and corrosion resistance is also attracting attention because it can be measured in an environment that requires heat resistance and corrosion resistance depending on the structure of the sensing unit.

For example, Patent Document 1 introduces an interference-type optical fiber sensor having a high heat resistance in which a sensing portion is composed only of a heat-resistant material such as a heat-resistant ferrule and a heat-resistant adhesive (FIG. 3). The sensing unit 100 of this Patent Document 1 is applied to the ferrule 102 by sensing a dimensional change of the space 104 using reflection and interference between the metal plated end surface of the optical fiber 101 and the metal plated end surface of the optical fiber 105. It detects physical quantities. In the sensing unit 100, optical fibers 101 and 105 made of quartz material having high heat resistance, heat-resistant ferrule 102 made of ceramic or glass such as zirconia having high heat resistance, and heat resistance such as ceramic adhesive or polyimide adhesive. Adhesive 103 is used to provide high heat resistance. The metal coating 107 is made of nickel, copper or the like and reinforces the optical fiber 101.

Optical fiber communication is rapidly spreading with the increase in data transmission. Until recently, fields such as trunk networks and relay networks were mainstream, but in recent years, their use in subscriber networks has increased. In such optical fiber communication, the LD light source module and light receiving module responsible for transmission / reception along with the optical fiber are the most important parts, but with the spread to the subscriber network, surface processing is suitable for mass production of these parts. Mounting technology is being studied. The surface mounting technology is a technology established by mounting electronic components, but the entire mounting components are exposed to high heat of 200 ° C. or higher, not local heating. For this reason, high-temperature heat resistance has begun to be required for mounting components.

Patent Document 2 introduces a ferrule with an optical fiber that is used in a surface mounting module and has improved heat resistance. FIG. 4 is a cross-sectional view schematically showing a ferrule 200 with an optical fiber used in the module for planar mounting disclosed in Patent Document 2, and is composed of an optical fiber 201, a ferrule 202, and an adhesive 203. Yes. Patent Document 2 discloses that polyimide resin or low-melting glass is used as the adhesive 203. The glass transition point of the polyimide resin is about 270 ° C., and the glass transition point of the low melting point glass is about 300 ° C., while the temperature of the solder reflow furnace is about 240 ° C. Therefore, the softening of the adhesive does not occur and sufficient optical accuracy can be maintained.

As described above, high heat resistance is required for optical fiber parts used for optical sensors and optical communication.
Japanese Patent Laid-Open No. 10-319241 Japanese Patent Laid-Open No. 2002-14260

However, conventional optical fiber components have the following problems with respect to heat resistance.
For example, in the sensing unit for an optical fiber sensor disclosed in Patent Document 1, residual stress is generated due to a difference in thermal expansion between the ferrule and the optical fiber during heat curing of a ceramic adhesive or polyimide resin used as a bonding material between the optical fiber and the ferrule. To do. This may cause the optical fiber to break at the joint between the optical fiber and the ferrule.
When polyimide resin is used, it is necessary to increase the contact surface between polyimide and optical fiber in order to obtain sufficient strength. However, if the contact surface is increased, the thermal expansion coefficient of polyimide is more than five times that of ferrules. There was a problem of pulling the optical fiber with polyimide. For this reason, there is a problem in that the space 104 is expanded due to causes other than the original deformation of the ferrule, resulting in a measurement error.

  In addition, in the ferrule with an optical fiber for surface mounting in Patent Document 2, polyimide resin or low melting glass is used as an adhesive, but the low melting glass contains glass powder having a particle size of 10 μm or more before melting. It was necessary to enlarge the gap between the ferrule and the optical fiber. As described above, when the gap between the ferrule and the optical fiber is increased, it is difficult to make the axis of the ferrule and the axis of the optical fiber coincide with each other, resulting in a problem that connection loss increases. On the other hand, when a polyimide resin is used, there is a problem that the strength is weak and cracks are generated due to thermal shock, and sufficient bonding cannot be obtained.

  Therefore, a first object of the present invention is to provide an optical fiber component with little optical axis deviation and high heat resistance.

  The second object of the present invention is to provide an optical device having excellent optical characteristics and high heat resistance.

In order to achieve the above object, an optical fiber component according to the present invention is an optical fiber component in which at least one end of an optical fiber is fixed in an inner hole of a cylindrical body, and one end of the optical fiber is When the inner surface of the cylindrical body is partitioned into n areas (n is an integer of 3 or more) in the circumferential direction as viewed in a cross-section in a direction orthogonal to the axial direction of the cylindrical body, each of the n areas A contact portion that partially contacts the inner peripheral surface of the cylindrical body, and the optical fiber and the cylindrical body are bonded to each other with a bonding material present in the non-contact portion. And
An optical device according to the present invention includes the optical fiber component according to the present invention, and an optical element bonded to one end surface of the cylindrical body so as to close the inner hole of the cylindrical body of the optical fiber component. It is characterized by that.

Since the optical fiber component according to the present invention configured as described above can hold the optical fiber at three or more contact portions, the concentricity of the cylindrical body and the optical fiber can be increased, and the Since the optical fiber and the cylindrical body can be bonded at the non-contact portion with a bonding material such as a glass material having high heat resistance, the heat resistance can be increased.
Further, the optical device according to the present invention is configured using optical fiber components having no optical axis misalignment and high heat resistance according to the present invention, so that an optical device having excellent optical characteristics and high heat resistance is provided. can do.

DESCRIPTION OF EMBODIMENTS Hereinafter, an optical fiber component according to an embodiment of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
1A is a cross-sectional view (a) and an end view (b) showing a configuration of an optical fiber component (ferrule with optical fiber) 10a according to a first embodiment of the present invention.

  The optical fiber component 10a includes an optical fiber 11 made of quartz, glass, or the like, a ferrule 12a that is a cylindrical body made of a ceramic such as zirconia or alumina, a glass, or nickel, and a bonding material made of, for example, a glass 13.

In the optical fiber component 10a, the ferrule 12a has an inner hole 3a including an insertion portion 1a and a fixing portion 2a having a smaller diameter than the insertion portion 1a, and the optical fiber 11 is inserted into the inner hole 3a. The optical fiber 11 is fixed by the bonding material 13 at the fixing portion 2a.

The optical fiber component 10a according to the first embodiment is characterized in the shape of the fixing portion 2a of the inner hole 3a. The fixing portion 2a fixes the optical fiber 11 without deviation of the optical axis and has high heat resistance. It is possible to provide.

In the optical fiber component 10a of the first embodiment, as shown in FIG. 1A (b), the fixed portion 2a has convex portions (contact portions) 2a ′ with which the optical fiber 11 contacts at three locations. The convex portion 2a ′ enables the optical fiber 11 to be fixed without any deviation of the optical axis. That is, the abutment portions of the three convex portions 2a ′ with the optical fiber 11 are provided so as to be equidistant from the axis of the fixed portion 2a (a distance corresponding to the radius of the optical fiber 11), and light having no optical axis deviation. The fiber 11 can be fixed. In the first embodiment, the three convex portions 2a ′ are preferably formed so that the respective contact portions are parallel to the central axis of the fixed portion 2a. That is, it is preferable that this convex part 2a 'is comprised by the protrusion extended from the one end of the fixing | fixed part 2a to the other end. Moreover, it is preferable that three convex part 2a 'is formed at equal intervals.

Further, in the optical fiber component of the first embodiment, in the fixing portion 2a, between the three convex portions 2a ′ (non-contact portion), between the optical fiber 11 and the glass material having heat resistance, Sufficient air gap of, for example, 10 μm or more is secured for fixing with the brazing material. As a result, it is possible to apply a bonding material containing glass powder, or to melt and infiltrate the glass material or the brazing material, thereby ensuring a strong bonding with high heat resistance.

According to the optical fiber component of the first embodiment configured as described above, it is possible to provide an optical fiber component that holds the optical fiber with high positional accuracy in the through hole of the ferrule and has high heat resistance. Thereby, for example, it is possible to provide an optical fiber component (for example, a component for a connector) that can be used in an optical communication field in which a single mode fiber having a core portion with a diameter of about 10 μm is used and that can be surface-mounted.

In the first embodiment, the processing of the through hole of the ferrule 12a can be performed by cutting or laser processing in a ferrule using ceramics or glass. In the case of a ferrule using a metal such as nickel, It can be precisely manufactured by electrocasting.

The adhesive 13 is preferably made of low melting point glass. That is, a relatively low melting point glass has a melting temperature of about 300 ° C., and its linear thermal expansion coefficient is close to that of ceramics, metal, glass, etc., so that the residual stress during cooling can be sufficiently reduced and the bonding strength can be increased. .

  In the first embodiment described above, the convex portion 2a ′ is provided at three locations in the fixed portion 2a. However, the present invention is not limited to this, and the convex portion 2a ′ may be provided at three or more locations. .

The specific embodiment according to the present invention has been described above according to the first embodiment. However, the present invention is not limited to the configuration of the first embodiment, and the inner hole (through hole 12a) of the cylinder (ferrule). An optical fiber component in which at least one end of an optical fiber is fixed is configured as follows.
That is, in the optical fiber component of the present invention, the cylindrical body (ferrule) is viewed from a cross section orthogonal to the axial direction thereof, and as shown in FIG. When the surface is divided into n equal parts in the circumferential direction (n is an integer of 3 or more), and a virtual area Y divided into n areas by the virtual equal line X is set, an optical fiber is partially in each area. An abutting portion is provided so as to abut.
Then, the optical fiber can be inserted into the inner hole of the cylinder (ferrule) so as to contact the n contact parts, and the inner circumference of the cylinder and the non-contact part between the contact parts It joins to the space | gap between surfaces with a joining material.

Next, an example of the manufacturing method of the optical fiber component which concerns on Embodiment 1 of this invention is shown.
<Production of ferrule>
When the ferrule 12a is manufactured using, for example, zirconia ceramics, first, a molded body that is a precursor of the ferrule 12a is manufactured. The molded body is produced by kneading a binder and a solvent into zirconia ceramic raw material powder, and then extruding the molded body into a cylindrical body having an inner hole. Next, the molded body obtained by the molding process is cut into a desired size, degreased, and fired at a temperature of about 1500 ° C. to produce a sintered body. Thereafter, the sintered body is polished with a wire having diamond abrasive grains so that the inner hole and the outer periphery have predetermined dimensions. At this time, the convex portion 2a ′ provided in the inner hole of the ferrule 12a may be formed by wire processing, or may be formed by laser processing. Moreover, this convex part 2a 'may form convex part 2a' in the state of a molded object by providing a groove | channel in the outer peripheral part of the core pin for forming the inner hole of a molded object. The ferrule 12a is manufactured through the above steps.

<Fabrication of optical fiber parts>
The optical fiber component can be manufactured by inserting and fixing the optical fiber 11 in the inner hole of the ferrule 12a. Since the optical fiber component of the present invention has a configuration in which the inner peripheral surface of the ferrule 12a and the outer peripheral portion of the optical fiber 11 are partially in contact with each other at three or more locations, when the optical fiber 11 is inserted into the ferrule 12a, the following I made the following ideas. When inserting the optical fiber 11 made of quartz into the ferrule 12a made of zirconia, the ferrule 12a may be inserted while being heated at 100 to 200 ° C. This is because the ferrule 12a has a larger coefficient of thermal expansion than the optical fiber 11, so that when heated, a small gap is formed between the optical fiber 11 and the ferrule 12a, and the optical fiber 11 can be easily inserted. When the ferrule 12a is cooled to room temperature after the optical fiber 11 is inserted, the ferrule 12a contracts so that the outer peripheral portion of the optical fiber 11 and the contact portion (convex portion 2a ′) provided in the inner hole of the ferrule 12 come into contact. become. Finally, the bonding material 13 is injected and fixed to the non-contact portion between the optical fiber 11 and the ferrule 12a. In this step, if the bonding material 13 is an adhesive, it may be injected into the gap (non-contacting portion) between the optical fiber 11 and the ferrule 12a, but in the case of a glass material or brazing material, the optical fiber 11 and the ferrule. When the abutting end of 12a is made downward and the bonding material 13 is melted and poured from above, the bonding material 13 can be efficiently injected into the non-contacting portion. Thereafter, the bonding material 13 is cured by cooling or the like, and the optical fiber 11 is fixed in the inner hole of the ferrule 12a, whereby an optical fiber component is obtained.

Hereinafter, other embodiments within the scope of the present invention will be described.
Embodiment 2. FIG.
FIG. 1B is a cross-sectional view (a) and an end view (b) showing the configuration of the optical fiber component 10b according to the second embodiment of the present invention.
The optical fiber component 10b of the second embodiment is configured in the same manner as the optical fiber component of the first embodiment, except that it is configured using a ferrule 12b having a through-hole 3b whose cross-sectional shape of the fixing portion 2b is a triangle. The

In the optical fiber component 10b according to the second embodiment, as shown in FIG. 1B (b), in the fixing portion 2b, the abutment portion 2b in which the optical fiber 11 abuts at the center of each side of the triangle in any cross section. A fixing portion 2b is formed so as to have a ', and the structure of the fixing portion 2b enables the optical fiber 11 to be fixed without an optical axis shift. That is, the fixing portion 2b is formed so that the contact portion of the optical fiber 11 on each surface is equidistant from the axis of the fixing portion 2b, and thereby the optical fiber 11 can be fixed without any optical axis deviation. In the second embodiment, it is preferable that each contact portion is formed so as to be parallel to the central axis of the fixed portion 2b. Moreover, it is preferable that the cross-sectional shape of the fixing | fixed part 2b is an equilateral triangle, Thereby, the contact part of the optical fiber 11 can be made into equal intervals, and an optical axis shift can be prevented more reliably.

Further, in the optical fiber component 10b of the second embodiment, as shown in FIG. 1B (b), the fixing portion 2b has heat resistance between the three contact portions and the optical fiber 11. Sufficient air gap is secured for fixing with a glass material or brazing material. As a result, it is possible to apply a bonding material containing glass powder, or to melt and infiltrate the glass material or the brazing material, thereby ensuring a strong bonding with high heat resistance.

The optical fiber component of the second embodiment configured as described above has the same function and effect as those of the first embodiment.
Further, the optical fiber component of the second embodiment holds the optical fiber at the three abutting portions by forming a triangular cross-sectional shape without forming a convex portion in the inner hole that is the fixing portion. Therefore, the inner hole can be easily processed.

In the second embodiment, the cross-sectional shape of the fixing portion 2b is a triangle. However, the present invention is not limited to this, and a rectangular shape, a pentagon shape, a hexagon shape, or the like having three or more abutting portions is used. Other polygons may be used. As a method for producing such a cross-sectional shape, the core pin for producing the inner hole of the ferrule 12a precursor (molded product) by the above-described extrusion molding method can be easily produced by making it into a polygonal shape. It is also excellent in mass productivity.
Further, there is no problem even if the corners have R, and the optical fiber 11 can be supported.

Embodiment 3 FIG.
The optical fiber component 10c according to the third embodiment of the present invention is an optical fiber component according to the first or second embodiment in which a metal coating 14 (metal part) such as Ni, Cu, Au or the like is applied as the optical fiber 11. Using a fiber, a metal film is formed on the inner peripheral surface of the fixing portion 2a or 2b by plating or vapor deposition, and a brazing material is used as the bonding material 13 (FIG. 3C).
In the third embodiment, portions other than those described above are configured in the same manner as the optical fiber component of the first or second embodiment.

  In the optical fiber component 10c of the third embodiment configured as described above, the molten brazing material penetrates the gap between the optical fiber that can be a non-contact portion between the contact portions and the inner peripheral surface of the cylindrical body. Since it can be made as large as possible, it can be easily joined using a brazing material. Here, it is preferable to use a brazing material having a eutectic point such as AuSn or AuGe that melts at about 300 ° C. in order to increase heat resistance.

  Moreover, in this Embodiment 3, it is preferable that the joining material 13 contains the same metal as the metal contained in the metal part 14 which coat | covers the optical fiber 11, Thereby, the thermal expansion of the joining material 13 and the metal part 14 is carried out. Since it can be set as the structure with which the coefficient approximated, it becomes possible to improve joining strength.

In the optical fiber components of Embodiments 1 to 3 described above, the inner hole 3a has the insertion portion 1a having a diameter larger than that of the fixing portion 2a (2b), so the optical fiber 11 is inserted into the inner hole 3a. Thereafter, the bonding material 13 is inserted into the insertion portion 1a in a solid state, and the bonding material 13 is softened or melted so as to penetrate into the gap between the optical fiber and the inner peripheral surface of the fixing portions 2a and 2b. it can.
Moreover, it is preferable that the boundary part of the insertion part 1a and the fixing | fixed part 2a is inclined so that a diameter may become small gradually, as shown to FIG. The material 13 can be easily penetrated into the gap between the optical fiber and the inner peripheral surfaces of the fixing portions 2a and 2b, and the bonding strength can be further increased.

Embodiment 4 FIG.
FIG. 2A is a cross-sectional view showing the configuration of the optical device 20a according to the fourth embodiment of the present invention, and the optical device is configured using the optical fiber component according to the second embodiment.
Specifically, the optical element 25 is fixed to the end face of the ferrule 12a (12b) into which the optical fiber is inserted by the bonding material 26 so as to close the inner hole.
Here, as the optical element 25, various elements such as a Faraday rotator, a Pockels element, and an etalon filter can be selected. The bonding material 26 may be a glass material or a brazing material as with the bonding material 13. However, if the melting point is lower than that of the bonding material 13, the bonding material 13 is melted when the bonding material 26 is bonded. It is desirable because there is no.

The optical device according to the fourth embodiment configured as described above has a high concentricity between the optical fiber and the ferrule in the optical fiber component according to the present invention that forms part of the optical device. Efficiency can be increased and loss due to connection can be reduced.
Moreover, since the optical fiber component according to the present invention has high heat resistance, an optical device having high heat resistance can be configured.

  Further, in the optical device according to the fourth embodiment, as shown in FIG. 2B, a graded index fiber 27 having a lens effect is provided at the tip of the optical fiber 11, and a pure silica fiber 28 for adjusting the optical distance is fused. Therefore, it is preferable to connect with an optical element, and thereby, the coupling efficiency between the optical fiber component and the optical element can be further increased.

As an example, an optical device shown in FIG. 2B was produced.
An etalon filter was used as the optical element 25. The etalon filter was manufactured by forming a partial reflection film having a function of reflecting a part of the irradiated light and transmitting the other light on both end faces of a quartz block of about 100 μm. This quartz has an optical path length change rate of about 10 ppm / ° C., and when used as an etalon filter, the transmission or reflection wavelength changes according to the temperature and functions as a temperature sensor. In this embodiment, the reflection wavelength is used.

As the optical fiber 11, a single-mode fiber coated with a polyimide resin having a fused portion of a graded index fiber 27 and a pure silica fiber 28 was used, and the coating at the connection with the ferrule 12 was removed.
The ferrule 12 is made of zirconia having an outer diameter of 2.5 mm, and the inner hole (fixed portion) is processed with a wire to which diamond is attached so that the cross-sectional shape thereof is a regular triangle having a side of 216.5 μm. did. The corners of this equilateral triangular section are arcuate (R is attached). Moreover, the center shift | offset | difference in a fixing | fixed part was less than 1 micrometer.

  Moreover, it processed so that the internal diameter of the insertion part 1a of the ferrule 12 might become a circle of 1 mm. As the bonding material 13, glass made of lead-boron-silicon or the like having a glass transition point of 250 ° C. or higher and a melting point of 350 ° C. or higher was used. For this bonding, glass as the bonding material 13 was preliminarily baked into a cylindrical shape so that the inner diameter was 200 μm and the outer diameter was 1 mm, and the glass was inserted into the ferrule insertion portion 1a.

Then, the optical fiber 11 is inserted into the ferrule 12 and heated on the hot plate so that the fixed end side of the optical fiber 11 of the ferrule 12 is on the bottom (processing temperature is about 400 ° C. for 10 minutes). By infiltrating the material into the fixed part, it was made to reach one end of the ferrule 12 and joined. Next, this end was mirror polished to produce a ferrule with an optical fiber.

Next, an etalon filter was connected to the end of the ferrule 12 with a bonding material 26. The bonding material 26 is made of glass having a melting temperature of 350 ° C. or lower, and has a melting temperature lower than that of the previously used bonding material 13.

Thus, the optical device of the Example was produced and evaluated.
The etalon filter used in this embodiment uses reflected light, and the light emitted from the optical fiber 11 needs to be incident again on the optical fiber 11 after being reflected by the etalon filter. For this reason, if the reflecting film of the etalon filter is not disposed perpendicular to the optical axis of the optical fiber, it will not be re-incident efficiently. However, in the optical device of this embodiment, the optical fiber 11 is fixed to the ferrule 12 with high concentricity. The angle deviation (shift of the reflection film with respect to the plane perpendicular to the optical axis of the optical fiber) was within 0.2 degrees. On the other hand, in the conventional device, the angle deviation sometimes occurs 1 degree or more. Furthermore, in the present example, by using the graded index fiber 27 having a lens effect, it was possible to make the light incident again with a reflectance of 90% or more. This means that the coupling efficiency between the optical fiber and the optical element is almost 100%.

They are sectional drawing (a) which shows the structure of the optical fiber component of Embodiment 1 which concerns on this invention, and an end elevation (b). They are sectional drawing (a) which shows the structure of the optical fiber component of Embodiment 2 which concerns on this invention, and an end elevation (b). It is sectional drawing which shows the structure of the optical fiber component of Embodiment 2 which concerns on this invention. It is sectional drawing which shows the structure of the optical device of Embodiment 3 which concerns on this invention. It is sectional drawing which shows the structure of the optical device of the modification of Embodiment 3 which concerns on this invention. It is sectional drawing which shows the structure of the sensor part of the conventional interference type optical fiber sensor. It is sectional drawing which shows the structure of the conventional ferrule with an optical fiber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Insert part, 2a, 2b fixing | fixed part, 2a 'convex part (contact part), 2b' contact part, 3a, 3b inner hole, 10a, 10b, 10c Optical fiber component, 11 Optical fiber, 12a, 12b Ferrule ( Cylinder), 13, 26 bonding material, 14 metal coating, 20a, 20b optical device, 25 optical element, 27 graded index fiber, 28 pure silica fiber.

Claims (6)

An optical fiber component in which at least one end of an optical fiber is fixed in an inner hole of a cylindrical body,
One end of the optical fiber is divided into n regions obtained by sectioning the inner surface of the cylindrical body into n equal parts (n is an integer of 3 or more) in the circumferential direction as viewed in a direction orthogonal to the axial direction of the cylindrical body. In some cases, each of the n regions is provided with a contact portion that partially contacts the inner peripheral surface of the cylindrical body, and the optical fiber and the cylindrical body are joined with a non-contact portion. Optical fiber parts that are joined together. 2. The optical fiber component according to claim 1, wherein the inner hole of the cylindrical body has a polygonal shape in a cross-sectional view in a direction orthogonal to the axial direction of the cylindrical body. One end of the optical fiber is fixed in the inner hole on one end side of the cylindrical body, and the optical fiber inserted in the inner hole on the other end side of the cylindrical body The optical fiber component according to claim 1, wherein the optical fiber component is disposed with a peripheral surface and a gap. A metal portion is provided on the outer periphery of one end of the optical fiber, and the bonding material contains the same metal as the metal portion, and the bonding material is bonded to the optical fiber at the metal portion and One end is fixed, The optical fiber component in any one of Claims 1-3 characterized by the above-mentioned. An optical device comprising: the optical fiber component according to any one of claims 1 to 4; and an optical element bonded to one end surface of the cylindrical body so as to close an inner hole of the cylindrical body of the optical fiber component. . The optical device according to claim 5, wherein a part of the optical fiber is composed of a graded index fiber.

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