JP2004085613A - Optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device which is inexpensive and is highly reliable. <P>SOLUTION: The optical device 1 has a base member 2 and a coating 4 of a coated optical fiber ribbon 3 is supported atop the base member 2. Also, the base member 2 is provided with a recess 5 and the recess 5 is provided with a fiber fixing section 7 formed by fixing respective bare fibers 6 exposed by removing the coating 4 at the intermediate portion of the fiber ribbon 3 with a resin. The fixing section 7 is provided with a crossing groove 9 formed diagonally with the axes of the bare fibers 6 so as to part the respective bare fibers 6. An optical member 10 for reflecting part of the signal light transmitted in the bare fibers 6 is inserted into the crossing groove 9. A photodetector 12 for photodetecting the light reflected by the optical member 10 is fixed to the under surface of a supporting member 11 placed on the fixing section 7. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical device for monitoring the light intensity of an optical signal transmitted through an optical fiber.
[0002]
[Prior art]
As an optical device for monitoring an optical signal transmitted through an optical fiber, for example, a device described in Japanese Patent Application Laid-Open No. 2-15203 is known. The optical fiber type optical demultiplexer described in this publication has a substrate on which an optical fiber is fixed on an upper surface, and a wavelength filter is inserted and bonded in a groove formed in the substrate. The photodetector is provided on the substrate so as to face the reflection surface of the wavelength filter.
[0003]
[Problems to be solved by the invention]
However, in the above-mentioned prior art, since the optical fiber is inserted and fixed in the long groove formed on the upper surface of the substrate, the groove processing of the substrate is required, and the manufacturing cost is increased. In such a structure, when the optical fiber is fixed to the long groove, the optical fiber may be erroneously damaged, and in this case, the reliability of the optical device may be reduced.
[0004]
An object of the present invention is to provide an inexpensive and highly reliable optical device.
[0005]
[Means for Solving the Problems]
The optical device of the present invention is provided with a base member, a fiber fixing portion provided on the base member and fixing the bare fiber with a resin, and a bare fiber provided at a portion including the fiber fixing portion, so as to cut the bare fiber. A transverse groove formed obliquely to the axis of the optical member, an optical member inserted into the transverse groove and reflecting or diffracting a part of the signal light transmitted through the bare fiber, and detecting the light reflected or diffracted by the optical member And a photodetector.
[0006]
By fixing the bare fiber with the resin as described above, it is not necessary to form a fiber groove for positioning and fixing the bare fiber on the upper surface of the base member. Therefore, manufacturing cost can be reduced, and an optical device having an optical member, a photodetector, and the like can be realized at low cost. Also, since the bare fiber does not hit the hard wall surface of the fiber groove and is not damaged, the reliability of the optical device can be improved. Further, since it is not necessary to form a groove in the base member, the manufacturing process can be simplified.
[0007]
Preferably, the bare fiber is formed by removing the covering portion of the intermediate portion of the optical fiber core, and the covering portions on both sides of the bare fiber are supported on the upper surface of the base member. In this case, for example, when forming the fiber fixing portion, the covering portions on both sides of the bare fiber are previously supported on the upper surface of the base member, so that the bare fiber is fixed in a state inclined in the height direction of the base member. Can be prevented. Thus, the optical signal reflected or diffracted by the optical member is effectively incident on the photodetector, so that the light receiving characteristics of the photodetector can be stabilized.
[0008]
Also, preferably, the bare fiber is mounted on the base member. In this case, in a state where the bare fiber is fixed with the resin, the bending of the bare fiber in the height direction of the base member is suppressed. Thus, the optical signal reflected or diffracted by the optical member is effectively incident on the photodetector, so that the light receiving characteristics of the photodetector can be stabilized.
[0009]
Further, preferably, at least one end side of the base member is provided with a connection member holding an end of the bare fiber. Thus, the optical device can be easily connected to another optical fiber component such as an optical connector.
[0010]
Further, preferably, the bare fiber has a clad removing portion in which an upper portion of the cladding is cut, and the transverse groove is formed so as to divide the cladding removing portion. In this case, since the distance between the light reflection position of the optical member and the photodetector can be shortened, when there are a plurality of photodetectors corresponding to a plurality of optical fiber cores, This is effective for suppressing crosstalk between adjacent photodetectors.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of an optical device according to the present invention will be described with reference to the drawings.
[0012]
First, a first embodiment of an optical device according to the present invention will be described with reference to FIGS. 1 is a vertical sectional view of the optical device according to the present embodiment, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is an enlarged sectional view of a main part of the optical device.
[0013]
1 to 3, an optical device 1 of the present embodiment has a base member 2 formed of silicon, quartz glass, or the like, and a multi-core optical fiber ribbon 3 is provided on the upper surface of the base member 2. The cover 4 is supported and fixed. Further, the base member 2 is provided with a concave portion 5 in which a plurality of bare fibers 6 exposed by removing the covering portion 4 at the intermediate portion of the multi-core optical fiber ribbon 3 are provided. A fiber fixing section 7 fixed with resin is provided.
[0014]
The bare fiber 6 includes a core 6a and a clad 6b (see FIG. 3). Further, the bare fiber 6 has a clad removing portion 8 in which the upper part of the clad 6b is cut flat in the axial direction of the bare fiber 6.
[0015]
The fiber fixing portion 7 is formed so as to cover each bare fiber 6 with resin over the entire circumference except for the cladding removing portion 8 (see FIG. 2). Further, the fiber fixing portion 7 is formed by die molding described later from the viewpoint of mass productivity. In addition, as a resin constituting the fiber fixing portion 7, an epoxy resin, a polyphenylene sulfide (PPS) resin, or the like is used.
[0016]
By fixing the bare fibers 6 collectively with resin in this way, it is not necessary to process a V-groove for positioning and fixing the bare fibers 6 on the upper surface of the base member 2, thereby reducing manufacturing costs. It becomes possible to plan. Further, when the bare fiber 6 is fixed, the bare fiber 6 does not hit the hard wall surface of the V-groove, so that the bare fiber 6 can be prevented from being damaged. Further, when the bare fiber is fixed to the V-groove on the substrate, two steps of processing the V-groove and fixing the arrangement of the bare fiber are required. However, the groove processing is performed by fixing the bare fiber 6 with resin. Since it becomes unnecessary, the manufacturing process of the optical device 1 can be simplified.
[0017]
The fiber fixing portion 7 is provided with a transverse groove 9 extending in the arrangement direction of the bare fibers 6. The transverse groove 9 is formed obliquely with respect to the axis of the bare fiber 6 so as to divide the clad removal portion 8 of each bare fiber 6. In the transverse groove 9, an optical member 10 for reflecting a part of the signal light transmitted through the core 6a of the bare fiber 6 obliquely upward at a predetermined reflectance is inserted. The optical member 10 is arranged obliquely with respect to the axis of the bare fiber 6 corresponding to the transverse groove 9.
[0018]
On the fiber fixing portion 7 located on the reflection surface side of the optical member 10, the support member 11 is mounted so as to protrude toward the optical member 10. A light detector 12 that receives light reflected by the optical member 10 and converts the light into an electric signal is fixed to a lower surface of the support member 11. The same number of the photodetectors 12 as the bare fibers 6 are provided. Each photodetector 12 is electrically connected to an external device (not shown) via a wire 13 provided on the upper surface of the support member 11.
[0019]
Here, each photodetector 12 is provided above each bare fiber 6, but since the upper cladding portion of each bare fiber 6 is cut off as described above, the upper cladding of the bare fiber 6 is reduced accordingly. The distance between the light reflection position of the optical member 10 and the photodetector 12 is shorter than in a case where the portion is not cut. Thereby, crosstalk between the adjacent photodetectors 12 can be effectively suppressed.
[0020]
A resin 14 for adjusting the refractive index to the core 6 a of the bare fiber 6 is filled in the transverse groove 9, and the optical member 10 is fixed by curing the resin 14. In addition, a portion including a portion between the optical member 10 and each photodetector 12 is filled with a resin 15 having a refractive index equivalent to that of the resin 14 so as to cover the optical member 10. As a result, since there is no discontinuous surface of the refractive index between the bare fiber 6 and the optical member 10 and between the optical member 10 and each photodetector 12, problems such as light reflection and scattering are prevented. Is done. Note that, as the resins 14 and 15, a silicone resin or the like is used.
[0021]
In the optical device 1 as described above, the signal light transmitted through the bare fiber 6 in the direction A in FIG. 3 passes through the resin 14 and the optical member 10 in the transverse groove 9 and is further incident on the bare fiber 6. Transmitted. At this time, a part of the signal light is reflected by the optical member 10 and goes obliquely upward. Then, the reflected light reaches the light detector 12 via the resin 15, and the light intensity of the reflected light is detected by the light detector 12. This light intensity is converted into an electric signal and sent to an external device (not shown) via the wire 13.
[0022]
Next, a method of manufacturing the optical device 1 as described above will be described with reference to FIG. First, the covering portion 4 in the middle part of the multi-core optical fiber ribbon 3 is removed to expose a plurality of bare fibers 6, and the covering portions 4 on both sides of each bare fiber 6 are supported on the upper surface of the base member 2. And fix it.
[0023]
Next, in this state, a resin is injected into the concave portion 5 of the base member 2 to form a fiber fixing portion 7 in which each bare fiber 6 is fixed with the resin (see FIG. 4A). Specifically, while the multi-core optical fiber tape core wire 3 fixed to the base member 2 is placed in a mold (not shown), a resin is filled in the mold, that is, a so-called insert molding is performed. The fixing part 7 is formed. By using such insert molding, each bare fiber 6 can be fixed relatively easily and firmly. At this time, by performing in a state where the coating portions 4 on both sides of the bare fiber 6 are fixed to the upper surface of the base member 2, the fiber fixing portion 7 is easily formed, and the bare fiber 6 is moved in the height direction of the base member 2. It can be prevented from being fixed in an inclined state.
[0024]
Next, the upper portion of the fiber fixing portion 7 is ground by a predetermined amount in the axial direction of the bare fiber 6 using a dicer or the like. This makes it possible to reduce the size of the optical device 1 in the height direction. Then, the upper portion of the clad 6b in a predetermined region of the bare fiber 6 is ground together with the fiber fixing portion 7 in the axial direction of the bare fiber 6 by a dicer or the like to form a clad removing portion 8 in the bare fiber 6. (See FIG. 4B). At this time, since the bare fiber 6 is hardly inclined with respect to the height direction of the base member 2, the upper portion of the clad 6b can be easily ground and the optical characteristics can be stabilized.
[0025]
Next, a groove is formed in a portion of the fiber fixing portion 7 where the clad removing portion 8 is formed in a direction oblique to the axial direction of the bare fiber 6 to form a transverse groove 9 (see FIG. 4C).
[0026]
Next, the optical member 10 is inserted into the transverse groove 9, and in this state, the resin 14 is filled into the transverse groove 9, and the optical member 10 is fixed. Further, the support member 11 on which the plurality of photodetectors 12 are mounted is mounted and fixed on the fiber fixing section 7, and the resin 15 is filled in a portion including the space between the optical member 10 and each photodetector 12. Thus, an optical device 1 as shown in FIG. 1 is obtained.
[0027]
As described above, according to the present embodiment, since the bare fiber 6 of the multi-core optical fiber ribbon 3 is fixed with the resin, an inexpensive and highly reliable optical device can be realized.
[0028]
Further, since the bare fiber 6 is fixed in a state where it is hardly inclined with respect to the height direction of the base member 2, the light reflected by the optical member 10 is sufficiently incident on the photodetector 12. Therefore, the light receiving characteristics of the photodetector 12 can be stabilized.
[0029]
In the present embodiment, the base member 2 having the concave portion 5 is used. However, a simple flat plate can be used instead of the base member 2. In this case, the transverse groove 9 for inserting the optical member 10 is formed over the fiber fixing portion and the flat plate.
[0030]
A second embodiment of the optical device according to the present invention will be described with reference to FIGS. In the drawing, the same or equivalent members as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0031]
FIG. 5 is a vertical sectional view of the optical device of the present embodiment, and FIG. 6 is a sectional view taken along line VI-VI of FIG. 5 and 6, the optical device 20 of the present embodiment has a base member 21, and the base member 21 is provided with a projection 22. On the upper surface on both sides of the convex portion 22 of the base member 21, the covering portion 4 of the multi-core optical fiber ribbon 3 is supported and fixed. A plurality of bare fibers 6 exposed by removing the covering portion 4 in the middle part of the multi-core optical fiber ribbon 3 are placed on the upper surface of the convex portion 22.
[0032]
Further, on the convex portion 22, a fiber fixing portion 23 in which each bare fiber 6 is fixed with resin is provided. The method of forming the fiber fixing portion 23 and the resin used are the same as those of the fiber fixing portion 7 in the first embodiment. Further, the transverse groove 9 for inserting the optical member 10 is formed over the fiber fixing portion 23 and the base member 21.
[0033]
In this embodiment, since each bare fiber 6 of the multi-core optical fiber ribbon 3 is placed on the upper surface of the convex portion 22, when the fiber fixing portion 23 is formed, the bare fiber 6 is attached to the base member 21. It does not bend in the height direction. Therefore, the light receiving characteristics of the photodetector 12 can be further stabilized.
[0034]
A third embodiment of the optical device according to the present invention will be described with reference to FIG. In the drawing, the same or equivalent members as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0035]
7, the optical device 30 of the present embodiment has a base member 31, and the base member 31 is provided with a concave portion 32 having the same structure as the concave portion 5 of the base member 2 in the first embodiment. The concave portion 32 is provided with a fiber fixing portion 7 in which a plurality of bare fibers 6 exposed by removing the coating portion 4 in the middle portion of the multi-core optical fiber ribbon 3 are fixed with resin.
[0036]
MT connector ferrules 33 are attached to both ends of the base member 31. The connector ferrule 33 has a pair of guide holes (not shown) for inserting guide pins, and a plurality of fiber holes 34 for inserting the bare fiber 6 of the multi-core optical fiber ribbon 3. ing. Such a connector ferrule 33 is arranged such that the front end face faces the outside of the base member 31. Then, a plurality of bare fibers 6 exposed by removing the coating portions 4 at both ends of the optical fiber ribbon 3 are inserted into the respective fiber holes 34 from the rear end face side of the connector ferrule 33, and each of the bare fibers 6 is attached with an adhesive or the like. The bare fiber 6 is fixed to the connector ferrule 33.
[0037]
Since the connector ferrule 33 holding both ends of the optical fiber ribbon 3 is attached to the base member 31, the optical fiber ribbon 3 can be easily connected to other optical fiber components via the connector ferrule 33. Can be connected.
[0038]
In the present embodiment, the connector ferrules 33 are provided at both ends of the base member 31. However, the connector ferrules 33 may be provided only at one end of the base member 31. The bare fiber 6 from which the entire coating 4 of the optical fiber ribbon 3 is removed and exposed may be assembled to the base member 31 and the connector ferrule 33.
[0039]
Further, instead of the connector ferrule 33, a fiber array holding the end of each bare fiber 6 may be provided. In this case, the connection between the optical fiber ribbon 3 and the PLC component can be easily performed.
[0040]
The preferred embodiment of the optical device according to the present invention has been described above, but the present invention is not limited to the above embodiment.
[0041]
For example, in the above-described embodiment, the bare fiber 6 is provided with the clad removing portion 8 in which the upper part of the clad 6b is cut, but such a cladding removing portion 8 is not necessarily provided. In this case, after forming the fiber fixing portion on the base member, the transverse groove 9 may be directly formed in the fiber fixing portion without grinding the upper portion of the fiber fixing portion, thereby simplifying the manufacturing process. Can be achieved.
[0042]
Further, in the above embodiment, the optical member 10 that reflects a part of the signal light transmitted through the bare fiber 6 is used, but the optical member that diffracts a part of the signal light transmitted through the bare fiber 6 is used. You can also.
[0043]
Further, in the above embodiment, the optical intensity of the optical signal transmitted through the bare fiber 6 of the multi-core optical fiber ribbon 3 is monitored, but the present invention relates to an optical device having a single-core optical fiber core. Is also applicable.
[0044]
【The invention's effect】
According to the present invention, since the fiber fixing portion in which the bare fiber is fixed with the resin is provided on the base member, it is not necessary to form a groove for positioning and fixing the bare fiber in the base member, thereby reducing the cost and cost. An optical device with high reliability can be obtained.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view showing a first embodiment of an optical device according to the present invention.
FIG. 2 is a sectional view taken along line II-II of FIG.
FIG. 3 is an enlarged sectional view of a main part of the optical device shown in FIG.
FIG. 4 is a diagram showing a manufacturing process of the optical device shown in FIG.
FIG. 5 is a vertical sectional view showing a second embodiment of the optical device according to the present invention.
FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;
FIG. 7 is a vertical sectional view showing a third embodiment of the optical device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical device, 2 ... Base member, 3 ... Optical fiber tape core wire, 4 ... Coating part, 6 ... Bare fiber, 6a ... Core, 6b ... Cladding, 7 ... Fiber fixing part, 8 ... Cladding removal part, 9 ... Transverse groove, 10 optical member, 12 photodetector, 20 optical device, 21 base member, 23 fiber fixing portion, 30 optical device, 31 base member, 33 connector ferrule (connection member).

Claims (5)

A base member,
A fiber fixing portion provided on the base member and fixing the bare fiber with resin,
A transverse groove provided at a portion including the fiber fixing portion and formed obliquely with respect to the axis of the bare fiber so as to divide the bare fiber,
An optical member that is inserted into the transverse groove and reflects or diffracts a part of the signal light transmitted through the bare fiber,
An optical detector for detecting light reflected or diffracted by the optical member. The bare fiber is formed by removing a coating portion of an intermediate portion of the optical fiber core,
The optical device according to claim 1, wherein the covering portions on both sides of the bare fiber are supported on an upper surface of the base member. The optical device according to claim 1, wherein the bare fiber is mounted on the base member. The optical device according to claim 1, wherein a connection member holding an end of the bare fiber is provided on at least one end of the base member. The bare fiber has a cladding removal portion in which the upper portion of the cladding is shaved,
The optical device according to claim 1, wherein the transverse groove is formed so as to divide the clad removing portion.

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