U.S. patent application number 14/248562 was filed with the patent office on 2014-08-07 for optical connector, optical connecting structure and method of manufacturing optical connector.
This patent application is currently assigned to SUMITOMO ELECTRIC INDUSTRIES, LTD.. The applicant listed for this patent is SUMITOMO ELECTRIC INDUSTRIES, LTD.. Invention is credited to Akira INOUE, Tomomi SANO, Dai SASAKI.
Application Number | 20140219611 14/248562 |
Document ID | / |
Family ID | 48169137 |
Filed Date | 2014-08-07 |
United States Patent
Application |
20140219611 |
Kind Code |
A1 |
SASAKI; Dai ; et
al. |
August 7, 2014 |
OPTICAL CONNECTOR, OPTICAL CONNECTING STRUCTURE AND METHOD OF
MANUFACTURING OPTICAL CONNECTOR
Abstract
An optical connecting member realizes an optical connecting
between a multi-core fiber and a plurality of single-core fibers by
a waveguide part which connects a first end face and a second end
face. With the optical connecting member, a connected end which is
connected to the first end face is a straight-line portion that is
orthogonal to the first end face in each of the plurality of
waveguide parts. In addition, a diverged end which is diverged to
the second end face is a straight-line portion that is orthogonal
to the second end face. Consequently, light that has passed through
the waveguide parts is emitted from the first end face and the
second end face substantially perpendicularly to the faces, thereby
enabling optical connecting loss to be favorably inhibited.
Inventors: |
SASAKI; Dai; (Yokohama-shi,
JP) ; SANO; Tomomi; (Yokohama-shi, JP) ;
INOUE; Akira; (Yokohama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SUMITOMO ELECTRIC INDUSTRIES, LTD. |
Osaka |
|
JP |
|
|
Assignee: |
SUMITOMO ELECTRIC INDUSTRIES,
LTD.
Osaka
JP
|
Family ID: |
48169137 |
Appl. No.: |
14/248562 |
Filed: |
April 9, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13523419 |
Jun 14, 2012 |
8727634 |
|
|
14248562 |
|
|
|
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Current U.S.
Class: |
385/59 |
Current CPC
Class: |
G02B 6/3885 20130101;
G02B 6/3807 20130101; G02B 6/2804 20130101; G02B 6/403 20130101;
G02B 6/3865 20130101 |
Class at
Publication: |
385/59 |
International
Class: |
G02B 6/38 20060101
G02B006/38 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 17, 2011 |
JP |
2011-135216 |
Apr 2, 2012 |
JP |
2012-084183 |
Apr 20, 2012 |
JP |
2012-096905 |
Claims
1-27. (canceled)
28. An optical connecting member for connecting a multi-core fiber
having a plurality of cores, and a plurality of single-core fibers,
comprising: a first end which is connected to an end face of the
multi-core fiber; a second end which is diverged to the plurality
of single-core fibers; an intermediate part positioned between the
first end and the second end; a plurality of waveguide parts which
extends so as to connect the first end and the second end, wherein
each of the plurality of waveguide parts includes a straight-line
portion in the first end, and at least an end of the straight-line
portion is connected with an end face of the first end, and the
straight-line portions are parallel to each other, and wherein each
of the plurality of waveguide parts spreads outward in the
intermediate part, and a pitch of the plurality of waveguide parts
on the second end is greater than that on the first end.
29. The optical connecting member according to claim 28, wherein
the plurality of waveguide parts are arrayed two-dimensionally at
the first end, and in one line at the second end.
30. The optical connecting member according to claim 28, wherein
each of the plurality of waveguide parts includes a core with
constant diameter, but the outer diameter gradually increases
toward the second end.
31. The optical connecting member according to claim 28, wherein an
angle of the straight-line portion relative to the end face of the
first end is within a range of 90 degrees.+-.0.5 degrees.
32. The optical connecting member according to claim 28, wherein
the first end has a shape configured to being fixed with the
multi-core fiber retained by an optical ferrule by a guide
member.
33. The optical connecting member according to claim 32, wherein
the first end has a cylindrical shape so that the first end can be
fixed with the multi-core fiber retained by a cylindrical ferrule
by a sleeve.
34. The optical connecting member according to claim 32, wherein an
overall outer shape of the optical connecting member is a
substantial hexahedron, and the optical connecting member has a
pair of fitting holes so that the first end can be fixed with the
multi-core fiber retained by a ferrule by a pair of guide pins.
35. The optical connecting member according to claim 28, wherein
each of the plurality of waveguide parts is a single-core
fiber.
36. The optical connecting member according to claim 28, wherein
the length of the first end is 5 times or more of a core diameter
of the multi-core fiber.
37. The optical connecting member according to claim 28, wherein
the length of the second end is 5 times or more of a core diameter
of the multi-core fiber.
38. The optical connecting member according to claim 28, further
comprising: a first fixing component configured to retain one end
of each of the plurality of waveguide parts at the first end,
wherein the first fixing component internally fixes the plurality
of waveguide parts so that the plurality of waveguide parts are
parallel to each other.
39. The optical connecting member according to claim 38, wherein
the first fixing component has a tapered part which spreads from
the first end side to the second end side so that the plurality of
waveguide parts can be easily spread.
40. The optical connecting member according to claim 28, further
comprising: a second fixing component configured to retain other
end of each of the plurality of waveguide parts at the second end,
wherein the second fixing component internally fixes the plurality
of waveguide parts so that the plurality of waveguide parts are
parallel to each other.
41. The optical connecting member according to claim 28, wherein
the plurality of waveguide parts are single-core fiber and include
a coated part, and wherein the coated part is retained in the
optical connecting member and the coated part extends from the
second end.
42. The optical connecting member according to claim 28, wherein
the first end has substantially cylindrical shape and the second
end has substantially rectangular shape, and wherein the
intermediate part has a shape which spreads from the first end side
to the second end side so as to connect the first end and the
second end.
43. The optical connecting member according to claim 28, wherein an
overall outer shape of the optical connecting member is a
substantial hexahedron.
44. The optical connecting member according to claim 28, wherein
the plurality of waveguide parts are respectively formed by filling
a fluid in the plurality of through-holes formed in the first end,
the second end and the intermediate part, wherein the fluid has a
higher refractive index than the first end, the second end and the
intermediate part.
45. The optical connecting member according to claim 28, wherein
the plurality of waveguide parts are each formed by coating an
optical reflective film on an inner wall of each of the plurality
of through-holes formed in the first end, the second end and the
intermediate part.
46. An optical connecting member for connecting a multi-core fiber
having a plurality of cores, and a plurality of single-core fibers,
comprising: a first end which is connected to an end face of the
multi-core fiber; a second end which is diverged to the plurality
of single-core fibers; an intermediate part positioned between the
first end and the second end; a plurality of waveguide parts which
extends so as to connect the first end and the second end, wherein
each of the plurality of waveguide parts includes a straight-line
portion in the first end, and at least an end of the straight-line
portion is connected with an end face of the first end, and the
straight-line portions are parallel to each other, and wherein the
length of the first end is 5 times or more of a core diameter of
the multi-core fiber.
47. The optical connecting member according to claim 46, wherein
the length of the second end is 5 times or more of a core diameter
of the multi-core fiber.
Description
TECHNICAL FIELD
[0001] The present invention relates to an optical connecting
member for efficiently connecting an optical component such as a
plurality of single-core fibers to an optical element such as a
multi-core fiber which can be suitably applied to an optical
communication system, as well as to an optical connecting structure
of the foregoing optical connecting member and a method of
manufacturing the foregoing optical connecting member.
BACKGROUND ART
[0002] Conventionally, in order to provide the fiber to the home
(FTTH) service which enables the optical communication between one
transmitter station and a plurality of subscribers, a so-called
passive optical network (PON) system in which the respective
subscribers share one optical fiber by interposing a multiple-stage
optical splitter has been realized. Nevertheless, the PON system
entails technical problems such as congestion control and
securement of a receiver dynamic range against the increase in
transmission capacity in the future.
[0003] As one means for resolving the foregoing technical problems,
migration to the single star (SS) system can be considered. Upon
migrating to the SS system, since the number of fiber cores will
increase on the station side in comparison to the PON system,
realization of ultrafine and ultrahigh density optical cables is
essential on the station side. As optical fibers for achieving such
ultrafine and ultrahigh density optical cables, for instance,
preferably used may be a multi-core fiber comprising a plurality of
cores in a single clad.
[0004] As such multi-core fiber, for instance, the optical fiber
disclosed in Patent Literature 1 includes seven or more cores
disposed two-dimensionally in the cross section thereof. Moreover,
for instance, Patent Literature 2 discloses an optical fiber in
which a plurality of cores are arranged in parallel in a straight
line, and describes that the connecting of the optical waveguide
part and the semiconductor optical integrated element is
facilitated.
CITATION LIST
Patent Literature
[0005] Patent Literature 1: Japanese Unexamined Patent Application
Publication No. H05-341147 [0006] Patent Literature 2: Japanese
Unexamined Patent Application Publication No. H10-104443
SUMMARY OF INVENTION
Technical Problem
[0007] Nevertheless, the actual condition is that a network
resource; for instance, standard optical equipment or the like,
which is envisioned as the object to be connected to the foregoing
multi-core fiber having a plurality of cores, is configured on the
premise of being connected to the station via a single-core fiber.
Thus, the connecting configuration of the multi-core fiber and a
plurality of single-core fibers is important, and optical
connecting means having a simple configuration and capable of
inhibiting connecting loss is being demanded.
[0008] The present invention was devised in order to resolve the
foregoing problems, and an object of this invention is to provide
an optical connecting member capable of efficiently connecting,
with a simple configuration, an optical element such as a
multi-core fiber having a plurality of cores, and an optical
component such a plurality of single-core fibers, and an optical
connecting structure for connecting the foregoing optical
connecting member and an optical element or the like.
Solution to Problem
[0009] In order to achieve the foregoing object, the optical
connecting member according to the first aspect of the present
invention is an optical connecting member for connecting an optical
element including a plurality of optical input/output (I/O) parts
respectively having optical axes that are parallel to each other,
to other optical component, and comprises a main body part having a
first end on the optical element side and a second end on the other
optical component side, and a plurality of waveguide parts disposed
in the main body part and extending so as to connect the first end
and the second end. With this optical connecting member, the
plurality of waveguide parts are arrayed so as to correspond to an
array of the plurality of optical I/O parts and respectively have
straight-line portions which are parallel to each other at the
first end.
[0010] The optical connecting member according to this first aspect
realizes the optical connecting between an optical element such as
a multi-core fiber and an optical component such as a plurality of
single-core fibers by using a waveguide part which connects a first
end and a second end. With this optical connecting member, the
plurality of waveguide parts are arrayed so as to correspond to an
array of the plurality of optical I/O parts and respectively have
straight-line portions which are parallel to each other at the
first end. Consequently, since the optical axis of the plurality of
waveguide parts becomes parallel to each other on the first end
side, the optical axis of the optical connecting member and the
optical axis of the optical element such as a multi-core fiber can
be matched easily, and optical connecting loss can be favorably
inhibited. Moreover, with this optical connecting member, since
each of the plurality of waveguide parts comprises a region which
becomes parallel to each other on the first end side, it is
possible to maintain the parallelism of the waveguide parts even in
cases where the connecting face of the optical connecting member is
polished to a certain degree in order to obtain a favorable
connecting face.
[0011] With the optical connecting member according to the
foregoing first aspect, the plurality of waveguide parts may be
arrayed two-dimensionally so as to correspond to a two-dimensional
array of the plurality of optical I/O parts at the first end.
[0012] With the optical connecting member according to the
foregoing first aspect, the plurality of waveguide parts may
arrayed one-dimensionally so as to correspond to an array of the
other optical component and respectively have straight-line
portions which are parallel to each other at the second end. In the
foregoing case, since the optical axis of the plurality of
waveguide parts becomes parallel to each other on the second end
side, the optical axis of the optical connecting member and the
optical axis of the optical component such as a plurality of
single-core fibers can be easily matched, and optical connecting
loss can be favorably inhibited. Moreover, with this optical
connecting member, since each of the plurality of waveguide parts
comprises a region which becomes parallel to each other on the
second end side, it is possible to maintain the parallelism of the
waveguide parts even in cases where the connecting face of the
optical connecting member is polished to a certain degree in order
to obtain a favorable connecting face.
[0013] With the optical connecting member according to the
foregoing first aspect, the main body part may include a plurality
of through-holes having an inner diameter which is substantially
equal to an outer diameter of each of the plurality of waveguide
parts, and the plurality of waveguide parts may be respectively
housed and fixed in the plurality of through-holes. In the
foregoing case, the plurality of waveguide parts may be
respectively formed of a single-core fiber having a cladding
diameter which is equal to a distance between the plurality of
optical I/O parts. For example, when the optical element is a
multi-core fiber, the core array of the multi-core fiber is
normally formed so that the inter-core distance becomes equal.
Accordingly, based on the foregoing configuration, a first end in
which the waveguide parts are arrayed similar to the core array of
the multi-core fiber can be easily obtained.
[0014] With the optical connecting member according to the
foregoing first aspect, the plurality of waveguide parts may also
be respectively formed by filling a fluid, which has a higher
refractive index than the main body part, in the plurality of
through-holes formed in the main body part. Moreover, the plurality
of waveguide parts may also be each formed by coating an optical
reflective film on an inner wall of each of the plurality of
through-holes formed in the main body part. In both of the
foregoing cases, waveguide parts with inhibited optical connecting
loss can be easily configured.
[0015] With the optical connecting member according to the
foregoing first aspect, the first end may have a cylindrical shape.
In the foregoing case, upon fixing the optical element such as a
multi-core fiber to a general-purpose cylindrical ferrule, an end
face of the optical element such as a multi-core fiber and an end
face of the optical connecting member can be easily connected via a
sleeve. Moreover, the second end may be provided with a guide part
for connecting to the other optical component so that an optical
axis of the other optical component and an optical axis of each of
the plurality of waveguide parts at the second end coincide with
each other.
[0016] With the optical connecting member according to the
foregoing first aspect, end faces of the waveguide parts may be
arrayed at regular intervals at the first end. In the foregoing
case, for example, when the optical element is a multi-core fiber,
the core array of the multi-core fiber is normally configured as a
two-dimensional array so that the inter-core distance becomes
equal. Accordingly, the connecting of the multi-core fiber is
facilitated by forming the first end configured as described
above.
[0017] Moreover, in order to achieve the foregoing object, the
optical connecting member according to the first aspect of the
present invention is an optical connecting member for connecting a
multi-core fiber having a plurality of cores, and a plurality of
single-core fibers, and comprises a main body part including a
first end face which is connected to an end face of the multi-core
fiber, a second end face which is diverged to the plurality of
single-core fibers, and a plurality of waveguide parts which extend
so as to connect the first end face and the second end face. With
this optical connecting member, each of the plurality of waveguide
parts is a straight-line portion in which at least an end connected
with the first end face is orthogonal to the first end face.
[0018] This optical connecting member realizes the optical
connecting between a multi-core fiber and a plurality of
single-core fibers by using a waveguide part which connects a first
end face and a second end face. With this optical connecting
member, each of the plurality of waveguide parts is a straight-line
portion in which at least an end connected with the first end face
is orthogonal to the first end face. Consequently, light that has
passed through the waveguide parts is emitted from the first end
face and the second end face substantially perpendicularly to the
faces, and thereby it is possible to easily match the optical axis
of the multi-core fiber and the plurality of single-core fibers at
the connecting part, and favorably inhibit optical connecting
loss.
[0019] Moreover, in order to achieve the foregoing object, the
optical connecting member according to the second aspect of the
present invention is an optical connecting member for connecting an
optical element including a plurality of optical I/O parts
respectively having optical axes that are parallel to each other,
to other optical component, and comprises a main body part having a
first end on the optical element side and a second end on the other
optical component side, a plurality of waveguide parts disposed in
the main body part and extending so as to connect the first end and
the second end, and a first fixing component for retaining one end
of each of the plurality of waveguide parts at the first end. With
this optical connecting member, the first fixing component
internally fixes the plurality of waveguide parts so that the
plurality of waveguide parts are parallel to each other.
[0020] The optical connecting member according to this second
aspect realizes the optical connecting between an optical element
such as a multi-core fiber and an optical component such as a
plurality of single-core fibers by using a waveguide part which
connects a first end and a second end. With this optical connecting
member, the first fixing component fixes the plurality of waveguide
parts so that the plurality of waveguide parts are parallel to each
other on the first end side. Consequently, since the optical axis
of the plurality of waveguide parts becomes parallel to each other
on the first end side, the optical axis of the optical connecting
member and the optical axis of the optical element such as a
multi-core fiber can be matched easily, and optical connecting loss
can be favorably inhibited. Moreover, with this optical connecting
member, since each of the plurality of waveguide parts comprises a
region which becomes parallel to each other on the first end side,
it is possible to maintain the parallelism of the waveguide parts
even in cases where the connecting face of the optical connecting
member is polished to a certain degree in order to obtain a
favorable connecting face.
[0021] With the optical connecting member according to the
foregoing second aspect, the first fixing component may fix the
plurality of waveguide parts so that the plurality of waveguide
parts are arrayed two-dimensionally at the first end. In the
foregoing case, it is easy to cause the array of the optical I/O
parts of an optical element such as a multi-core fiber, which is
normally configured in a two-dimensional array, and the array of
the waveguide parts of the optical connecting member to
correspond.
[0022] With the optical connecting member according to the
foregoing second aspect, the first fixing component may include a
guide part for connecting to the optical element so that an optical
axis of each of the plurality of optical I/O parts of the optical
element and an optical axis of one end of each of the plurality of
waveguide parts coincide with each other. In the foregoing case,
since the first fixing component for fixing the waveguide parts
includes a guide part for matching the optical axes, the optical
axis of the optical element and the optical axis of the waveguide
parts can be easily matched.
[0023] The optical connecting member according to the foregoing
second aspect may further comprise a second fixing component for
retaining another end of each of the plurality of waveguide parts
at the second end. In the foregoing case, the second fixing
component fixes the plurality of waveguide parts at the second end
so that the plurality of waveguide parts are parallel to each
other. Consequently, since the optical axis of the plurality of
waveguide parts becomes parallel to each other also on the second
end side, the optical axis of the optical connecting member and the
optical axis of the optical element such as a plurality of
single-core fibers can be matched easily, and optical connecting
loss can be favorably inhibited. Moreover, with this optical
connecting member, since each of the plurality of waveguide parts
comprises a region which becomes parallel to each other on the
second end side, it is possible to maintain the parallelism of the
waveguide parts even in cases where the connecting face of the
optical connecting member is polished to a certain degree in order
to obtain a favorable connecting face.
[0024] With the optical connecting member according to the
foregoing second aspect, the second fixing component may fix the
plurality of waveguide parts so that the plurality of waveguide
parts are arrayed one-dimensionally at the second end. In the
foregoing case, it is easy to cause the array of the optical I/O
parts of an optical component such as a plurality of single-core
fibers, which is normally configured in a one-dimensional array,
and the array of the waveguide parts of the optical connecting
member to correspond.
[0025] With the optical connecting member according to the
foregoing second aspect, the second fixing component may include a
guide part for connecting to the other optical component so that an
optical axis of the other optical component and an optical axis of
another end of each of the plurality of waveguide parts coincide
with each other. In the foregoing case, since the second fixing
component for fixing the waveguide parts includes a guide part for
matching the optical axes, the optical axis of the optical
component and the optical axis of the waveguide parts can be easily
matched.
[0026] With the optical connecting member according to the
foregoing second aspect, the first or second fixing component may
be a component for use in insert molding. In the foregoing case, it
is possible to easily produce an optical connecting member in which
the positioning of the first or second fixing component in the main
body part has been performed with precision.
[0027] With the optical connecting member according to the
foregoing second aspect, the waveguide parts may be each formed of
a single-core fiber having a cladding diameter which is equal to a
distance between the plurality of optical I/O parts of the optical
element. The core array of an optical element such as a multi-core
fiber is normally formed so that the inter-core distance becomes
equal. Accordingly, based on the foregoing configuration, waveguide
parts which are arrayed in the same manner as the core array of the
optical element such as a multi-core fiber can be easily
obtained.
[0028] With the optical connecting member according to the
foregoing second aspect, an end face on the first end side may have
a substantial circular shape. In the foregoing case, upon fixing
the optical element such as a multi-core fiber to a general-purpose
cylindrical ferrule, an end face of the optical element such as a
multi-core fiber and the first end of the optical connecting member
can be easily connected via a sleeve.
[0029] With the optical connecting member according to the
foregoing second aspect, end faces of the waveguide parts may be
arrayed at regular intervals at the first end. The core array of
the optical element such as a multi-core fiber is normally
configured as a two-dimensional array so that the inter-core
distance becomes equal. Accordingly, the connecting with an optical
element such as the multi-core fiber is facilitated by comprising
the first end configured as described above.
[0030] Moreover, in order to achieve the foregoing object, the
optical connecting structure according to the present invention
comprises any one of the optical connecting members described
above, and an optical element which includes a plurality of optical
I/O parts respectively having optical axes that are parallel to
each other, and which is connected to the optical connecting
member. With this optical connecting structure, the optical element
is connected to the optical connecting member so that the plurality
of waveguide parts of a first end face on the optical element side
of the first end and the plurality of optical I/O parts of the
optical element face each other. In the foregoing case, the
plurality of optical I/O parts of the optical element may be
disposed in point symmetry around a predetermined rotating axis,
and connected by adjusting a rotating angle so as to face the
plurality of waveguide parts at the first end face. Consequently,
the optical element and the optical connecting member can be easily
connected.
[0031] With the foregoing optical connecting structure, the optical
element is a multi-core fiber in which a plurality of cores are
surrounded by a common clad, and the multi-core fiber may be
retained by an optical ferrule which is fixed by being positioned
relative to the optical connecting member by a guide member. In the
foregoing case, a restrictive structure for restricting a rotating
angle of the multi-core fiber may be provided in the multi-core
fiber and the optical ferrule. Consequently, the positioning of the
multi-core fiber and the optical connecting member in the rotating
direction is facilitated.
[0032] With the foregoing optical connecting structure, the optical
element is a receiving/emitting element in which a plurality of
light receiving/emitting parts are arrayed two-dimensionally, and
the optical connecting structure may further comprise a light
collection optical system for optically connecting each of the
plurality of light receiving/emitting parts of the
receiving/emitting element to the plurality of waveguide parts. In
the foregoing case, a receiving/emitting element comprising a
plurality of light receiving/emitting parts such as with VCSEL can
be connected to other optical component upon favorably inhibiting
connecting loss.
[0033] Moreover, the present invention may also be viewed as a
method of manufacturing, via insert molding, the optical connecting
member according to the foregoing second aspect. In other words,
the manufacturing method of an optical connecting member according
to the present invention comprises a step of preparing a plurality
of waveguide parts for configuring the optical connecting member
and a fixing component for use in insert molding, a step of
retaining, in the fixing component, one end of each of the
plurality of waveguide parts so that the plurality of waveguide
parts becomes parallel to each other, a step of disposing, in a
mold, the fixing component and the plurality of waveguide parts
each having one end that has been retained by the fixing component,
and a step of pouring a predetermined molding material in the mold
to perform insert molding.
[0034] With this manufacturing method of an optical connecting
member, provided is a step of retaining, in the fixing component,
one end of each of the plurality of waveguide parts so that the
plurality of waveguide parts becomes parallel to each other. The
plurality of waveguide parts retained in parallel as described
above and the fixing component for fixing the plurality of
waveguide parts are disposed in a mold and subject to insert
molding. In the foregoing case, the optical connecting member is
manufactured by each of the plurality of waveguide parts being
fixed with the fixing component so as to be parallel to each other.
Consequently, with this manufactured optical connecting member, the
optical axis of the plurality of waveguide parts becomes parallel
to each other. Thus, the optical axis of the optical connecting
member and the optical axis of the optical element such as a
multi-core fiber or the optical axis of the optical component such
as the plurality of single-core fibers can be easily matched, and
the optical connecting loss can be favorably inhibited.
Advantageous Effects of Invention
[0035] According to the present invention, an optical element
including a plurality of optical I/O parts, and other optical
component can be efficiently connected with a simple
configuration.
BRIEF DESCRIPTION OF DRAWINGS
[0036] FIG. 1 is a perspective view showing the optical connecting
member and the optical connecting structure according to the first
embodiment of the present invention;
[0037] FIG. 2 is a plan view with a part of the optical connecting
member illustrated in FIG. 1 broken away;
[0038] FIG. 3 is a diagram showing the first end face of the main
body part of the optical connecting member illustrated in FIG.
1;
[0039] FIG. 4 is a diagram showing the second end face of the main
body part of the optical connecting member illustrated in FIG.
1;
[0040] FIG. 5 is a perspective view showing an example of the
manufacturing process of the optical connecting member illustrated
in FIG. 1;
[0041] FIG. 6 is a perspective view showing the process that is
subsequent to the process of FIG. 5;
[0042] FIG. 7 is a perspective view showing the first end of the
main body part immediately after molding;
[0043] FIG. 8 is a diagram showing a modified example of the
optical connecting member according to the first embodiment of the
present invention;
[0044] FIG. 9 is a diagram showing another modified example of the
optical connecting member according to the first embodiment of the
present invention;
[0045] FIG. 10 is a perspective view showing a modified example of
the optical connecting structure according to the first embodiment
of the present invention;
[0046] FIG. 11 is a plan view showing the receiving/emitting
element that is used in the optical connecting structure shown in
FIG. 10;
[0047] FIG. 12 is a diagram showing a modified example of the
multi-core fiber and the optical ferrule used in the optical
connecting structure illustrated in FIG. 1;
[0048] FIG. 13 is a perspective view showing the optical connecting
member and the optical connecting structure according to the second
embodiment of the present invention;
[0049] FIG. 14 is a plan view with a part of the optical connecting
member illustrated in FIG. 13 broken away;
[0050] FIG. 15 is a diagram showing the first end face of the main
body part of the optical connecting member illustrated in FIG.
13;
[0051] FIG. 16 is a diagram showing the second end face of the main
body part of the optical connecting member illustrated in FIG.
13;
[0052] FIG. 17 is a perspective view showing the fixing component
configuring the optical connecting member illustrated in FIG. 13,
wherein (a) of FIG. 17 shows the first fixing component disposed on
the first end face side, and (b) of FIG. 17 shows the second fixing
component disposed on the second end face side;
[0053] FIG. 18 is a perspective view showing an example of the
manufacturing process of the optical connecting member illustrated
in FIG. 13, and is a diagram showing the process of preparing the
SCFs;
[0054] FIG. 19 is a perspective view showing the process of
inserting one end of the SCFs illustrated in FIG. 18 into the first
fixing component;
[0055] FIG. 20 is a perspective view showing the process of
inserting the other end of the SCFs illustrated in FIG. 19 into the
second fixing component;
[0056] FIG. 21 is a perspective view showing the process of
disposing the SCFs illustrated in FIG. 20 in the mold;
[0057] FIG. 22 is a perspective view showing the process of molding
that is performed after the process illustrated in FIG. 21;
[0058] FIG. 23 is a perspective view showing the first end of the
main body part immediately after molding;
[0059] FIG. 24 is a perspective view showing a modified example of
the fixing component configuring the optical connecting member
according to the second embodiment, wherein (a) of FIG. 24 shows a
modified example of the first fixing component disposed on the
first end face side, and (b) of FIG. 24 shows a modified example of
the second fixing component disposed on the second end face
side;
[0060] FIG. 25 is a diagram showing another modified example of the
optical connecting member, and
[0061] FIG. 26 is a diagram showing yet another modified example of
the optical connecting member.
DESCRIPTION OF EMBODIMENTS
[0062] The preferred embodiments of the optical connecting member
and the optical connecting structure are now explained in detail
with reference to the appended drawings.
First Embodiment
[0063] FIG. 1 is a perspective view showing the optical connecting
member and the optical connecting structure using the optical
connecting member according to the first embodiment of the present
invention. FIG. 2 is a plan view with a part of the optical
connecting member illustrated in FIG. 1 broken away. As shown in
FIG. 1, an optical connecting member 1 is an optical connecting
member for connecting a multi-core fiber (hereinafter referred to
as "MCF") 2, and a plurality of single-core fibers (hereinafter
referred to as "SCFs") 3. By using the optical connecting member 1,
the MCF 2 as one example of the optical element and the SCFs 3 as
one example of the optical component are optically connected to
configure an optical connecting structure C1.
[0064] The MCF 2 is a fiber in which a plurality of cores (optical
I/O parts) are disposed in the same clad so that their mutual
optical axes become parallel. Preferably, a plurality of cores of
the MCF 2 are disposed so that the inter-core distance thereof
becomes equal, respectively. While the core array may be linear
one-dimensional array, for instance, the core array is preferably a
two-dimensional array such as a triangular lattice or square
array.
[0065] The MCF 2 of this embodiment is of a triangular lattice
array, with one core at the center position of the clad and six
cores around the center core at 60.degree. intervals; that is, a
total of seven cores are disposed at mutually regular intervals. In
other words, the cores of the MCF 2 are disposed in point symmetry
around the rotating axis which is positioned at the center. For
instance, when there is no center core, a precise triangular
lattice array is not formed, but the present invention includes an
array that realizes a triangular lattice array upon assuming the
existence of the center core.
[0066] Meanwhile, the SCFs 3 are fibers, having a core of the same
diameter as the MCF 2, and in which the cladding diameter of at
least the tip portion is reduced so as to become equal to the
inter-core distance of the MCF 2. An MT connector 4 is mounted at
the tip of the SCFs 3, and the SCFs 3 are fixed by the MT connector
so that the optical axis of the tip portion of the SCFs 3 becomes
parallel to each other. A tip face 4a of the MT connector 4 is
provided with guide pins 5 for mounting the optical connecting
member 1, and the tips of seven SCFs 3 are exposed horizontally in
one line at a predetermined pitch according to the number of cores
of the MCF 2 between the guide pins 5.
[0067] The optical connecting member 1 comprises, as shown in FIG.
1 and FIG. 2, a main body part 11 formed from plastic resin such as
polyphenylenesulfide (PPS) resin or polyetherimide (PEI) resin
which is used for configuring a standard optical connector, and a
plurality of (in this example, seven) waveguide parts 12 provided
in the main body part 11. The main body part 11 has a first end 13
including a first end face 13a to be connected to an end face of
the MCF 2, a second end 14 including a second end face 14a to be
connected to an end face of the SCFs 3, and an intermediate part 15
positioned between the first end 13 and the second end 14.
[0068] The first end 13 has a cylindrical shape with the same
diameter as the outer diameter of a ferrule 7 into which the MCF 2
has been inserted, and the end face thereof is the first end face
13a having a circular cross section. The length of the first end 13
is, for example, 5 times or more of the core diameter of the MCF 2.
Meanwhile, the second end 14 is of a substantial hexahedron shape,
and the end face thereof is the second end face 14a having the same
shape as the tip face 4a of the MT connector 4.
[0069] As with the first end 13, the length of the second end 14
is, for example, 5 times or more of the core diameter of the MCF 2.
The second end 14 is provided with fitting holes 16 (guide parts)
into which the guide pins 5 of the MT connector 4 are fitted. The
intermediate part 15 has a shape which spreads toward the bottom
from the first end 13 side to the second end 14 side so as to
connect the cylindrical first end 13 and the substantially
rectangular second end 14.
[0070] More specifically, the waveguide part 12 is configured from
SCFs 18 tightly disposed (housed) in through-holes 17 extending in
the main body part 11 so as to connect the first end face 13a of
the first end 13 and the second end face 14a of the second end 14.
The through-holes 17 have an inner diameter which is substantially
equal to the outer diameter of the SCFs 18. The SCFs 18 are fibers
similar to the SCFs 3, and the cladding diameter thereof is reduced
so as to become equal to the inter-core distance of the MCF 2.
[0071] Each of the plurality of waveguide parts 12 is a
straight-line portion in which a connected end 12A which is
connected to the first end face 13a is orthogonal to the first end
face 13a. The connected end 12A formed from the straight-line
portion at the first end 13 of the plurality of waveguide parts 12
is arrayed so as to become parallel to each other. A diverged end
12B which diverges to the second end face 14a is a straight-line
portion which is orthogonal to the second end face 14a. The
diverged end 12B formed from the straight-line portion at the
second end 14 of the plurality of waveguide parts 12 is arrayed so
as to become parallel to each other.
[0072] The term "orthogonal" as used in this embodiment shows, for
example, that the angle relative to the first end face 13a is
within a range of 90 degrees.+-.0.5 degrees, but it is obvious to a
person skilled in the art that the foregoing range can be increased
or decreased as needed according to the connecting precision by the
optical connecting member. The length of the connected end 12A and
the diverged end 12B is, for example, five times or more of the
core diameter of the MCF 2. The intermediate portion of the
waveguide part 12 curves gently along the shape of the main body
part 11 between the first end face 13a and the second end face 14a,
and joins the connected end 12A and the diverged end 12B.
[0073] One end face of the waveguide part 12 is exposed on the
first end face 13a so as to cause the core position of the MCF 2
and the core position of the SCFs 18 to correspond, and, as shown
in FIG. 3, one core is disposed at the center position of the first
end face 13a and six cores are disposed around the center core at
60.degree. intervals; that is, a total of seven cores are disposed
at mutually regular intervals. The other end face of the waveguide
part 12 is exposed on the second end face 14a so as to cause the
core position of the SCFs 3 and the core position of the SCFs 18 to
correspond, and, as shown in FIG. 4, disposed horizontally in one
line at a predetermined pitch between the fitting holes 16.
[0074] In other words, as shown in FIG. 3, the plurality of
waveguide parts 12 are arrayed two-dimensionally so as to
correspond to the plurality of cores of the MCF 2 at the connected
end 12A thereof (that is, so that the straight lines connecting the
cores form a polygon). Meanwhile, as shown in FIG. 4, the plurality
of waveguide parts 12 are arrayed one-dimensionally so as to
correspond to the plurality of cores of the SCFs 3 at the diverged
end 12B thereof (that is, so that the straight lines connecting the
cores form a straight line).
[0075] With the optical connecting member 1 configured as described
above, the end face of the MCF 2 fixed by the ferrule 7 and the
first end face 13a of the main body part 11 are caused to come into
contact in a split sleeve 19 (guide member) in a state where the
core position of the MCF 2 and the position of the waveguide parts
12 on the first end face 13a are matched; that is, in a state where
the rotating angle is adjusted so that the cores of the MCF 2 and
the waveguide parts 12 on the first end face 13a face each other.
In addition, by fitting the guide pins 5 into the fitting holes 16
of the second end 14 and causing the tip face 4a of the MT
connector 4 and the second end face 14a of the main body part 11 to
come into contact, the MCF 2 and the SCFs 3 can be connected via
the waveguide parts 12.
[0076] Here, with the optical connecting member 1, in each of the
plurality of waveguide parts 12, the connected end 12A which is
connected to the first end face 13a is a straight-line portion
which is orthogonal to the first end face 13a, and the
straight-line portions are parallel to each other. Consequently,
the MCF 2 and the optical axis in the connecting part of the
waveguide part 12 can be matched easily. The diverged end 12B which
diverges to the second end face 14a is a straight-line portion
which is orthogonal to the second end face 14a, and the
straight-line portions are parallel to each other. Consequently,
the waveguide parts 12 and the optical axis in the connecting part
of the SCFs 3 can also be matched easily. Accordingly, in
comparison to cases where light is emitted obliquely from the first
end face 13a and the second end face 14a, optical connecting loss
can be inhibited favorably.
[0077] The foregoing optical connecting member 1 can be formed, for
example, via injection molding. In the foregoing case, foremost, as
shown in FIG. 5, a pair of molds 21 having recessed parts 22
according to the shape of the main body part 11 is prepared. The
recessed parts 22 respectively correspond to the shape of one half
portion and to the shape of the other half portion of the main body
part 11 in the width direction, and, when the molds 21 are closed,
form a space S (refer to FIG. 6) of the same shape as the main body
part 11 in the molds 21. The recessed parts 22 are provided with a
reduced diameter part 24 that is more on the tip side than the
forming position of the first end 13.
[0078] Next, a plurality of (same number as the number of cores of
the MCF2) molding pins 23 made from an elastic member are prepared,
and disposed between the recessed parts 22. When the pair of molds
21 is closed in this state, as shown in FIG. 6, the tips of the
respective molding pins 23 are bound to be parallel to each other
due to the reduced diameter part 24, and become a moderately
deformed state in the space S due to the elastic deformation.
Consequently, each of the molding pins 23 will have a straight-line
portion which is orthogonal to the first end face 13a and a
straight-line portion which is orthogonal to the second end face
14a. Thereafter, when resin is poured from a resin pouring hole
(not shown) of the molds 21 and the molding pin 23 is removed,
obtained is the main body part 11 formed with a plurality of
through-holes 17.
[0079] On the first end face 13a of the main body part 11 obtained
above, as shown in FIG. 7, a convex part 25 corresponding to the
shape of the reduced diameter part 24 will remain. Accordingly, by
removing the convex part 25 via grinding or the like, the first end
face 13a is formed. Since the through-holes 17 have mutually
parallel direct portions corresponding to the connected end 12A at
the first end 13, even if the foregoing grinding or the like is
performed, the parallelism of the optical axis of the waveguide
parts 12 is maintained. Finally, by inserting the SCFs 18 into the
respective through-holes 17, the optical connecting member 1 is
obtained. Note that when the amount of protrusion of the convex
part 25 is small (for example, around the same length as the core
diameter), the convex part 25 may be left as is. This is because,
even when connected with the MCF 2, it is unlikely that the convex
part 25 will become damaged.
[0080] The present invention is not limited to the foregoing
embodiment, and may be modified variously. For example, while in
the foregoing first embodiment the SCFs 18 were disposed in the
through-holes 17 to configure the waveguide parts 12, but as shown
in FIG. 8, it is also possible to form the waveguide parts 12 by
forming through-holes 37 having the same diameter as the core
diameter of the MCF 2, and filling a fluid 38 having a refractive
index that is higher than the main body part 11 in the through-hole
37. As the fluid 38, for example, matching oil containing silicone
resin or the like may be used.
[0081] Moreover, as shown in FIG. 9, it is also possible to form
the waveguide parts 12 by forming through-holes 47 having the same
diameter as the core diameter of the MCF 2, and coating the inner
wall of the through-holes 47 with an optical reflective film 48. As
the optical reflective film 48, for instance, a Au film formed via
electroless plating or the like may be used. The waveguide parts 12
with inhibited optical connecting loss can also be formed simply
with the foregoing configurations.
[0082] In addition, the SCFs 18 disposed in the through-holes 17
may extend from the second end face 14a with a sufficient length
(refer to FIG. 26 described later). Consequently, the SCFs 18
extending from the second end face 14a of the optical connecting
member 1 can be directly connected to another optical device
without having to use a guide pin. In the foregoing case, since
there will be no connecting part between the waveguide parts 12 and
the second end face 14a of the SCFs 3 unlike the foregoing
embodiments, there is no need for a straight-line portion in which
the diverged end 12B which diverges to the second end face 14a is
orthogonal to the second end face 14a. Moreover, in the foregoing
case, the SCFs 18 that are fixed inside the optical connecting
member 1 are preferably coated optical fibers.
[0083] In other words, the SCFs 18 preferably have a reduced
diameter on the first end face 13a side with the coating removed,
and at least a part of the coating is fixed inside the optical
connecting member 1. When forming this kind of optical connecting
member 1, used is a molding pin 23 in which one end is of an
enlarged diameter (corresponds to the coating diameter) and the
other end is of a reduced diameter (corresponds to the outer
diameter of the portion in which the coating was removed), and, by
disposing the enlarged diameter side to face the second end face
14a side, the same process described above may be used for
subjecting the main body part 11 to injection molding.
[0084] Moreover, with the foregoing embodiment, as shown in FIG. 1,
an optical connecting structure in which the optical connecting
member 1 is connected to the MCF 2 was explained. However, as shown
in FIG. 10, it is also possible to adopt an optical connecting
structure C2 in which the optical connecting member 1 is connected
to a receiving/emitting element 57 via a connecting lens 59 (light
collection optical system). The receiving/emitting element 57
comprises, as shown in FIG. 11, a plurality of (seven in the
example of FIG. 11) light receiving/emitting parts 52 which are
arrayed as with the core array of the MCF 2, and, according to the
optical connecting structure C2, the plurality of waveguide parts
12 and the optical axis of the plurality of light
receiving/emitting parts 52 can be matched easily as with the
optical connecting structure C1. Accordingly, even in cases where
the receiving/emitting element 57 is used as an example of the
optical element, in comparison to cases where light is emitted
obliquely from the first end face 13a and the second end face 14a,
optical connecting loss can be inhibited favorably.
[0085] Moreover, while the foregoing embodiment explained a case of
inserting the MCF 2 having a circular cross section into the
optical ferrule 7, as shown in FIG. 12, the configuration may also
be such that a flat face 62a is provided by cutting out a part of
the MCF 62, and providing a flat face 67a corresponding to the flat
face 62a to the inner hole of the optical ferrule 67. According to
this restrictive structure, the rotation of the MCF 62 can be
restricted by the optical ferrule 67. While the foregoing
manufacturing method configured the waveguide parts 12 by forming
the through-holes 17 in the main body part 11 by using the molding
pin 23, and thereafter disposing the SCFs 18 in the through-holes
17, it goes without saying that a configuration where the SCFs 18
are disposed in the pair of molds 21, without using the molding pin
23, in order to configure the waveguide parts 12 may also be
adopted.
Second Embodiment
[0086] The second embodiment of the present invention is now
explained.
[0087] FIG. 13 is a perspective view showing an example of a mode
of connecting the multi-core fiber and the plurality of single-core
fibers with the optical connecting member according to the second
embodiment of the present invention. FIG. 14 is a plan view with a
part of the optical connecting member illustrated in FIG. 13 broken
away. As shown in FIG. 13, an optical connecting member 101 is an
optical connecting member for connecting a multi-core fiber
(hereinafter referred to as "MCF") 102, and a plurality of
single-core fibers (hereinafter referred to as "SCFs") 103. By
using the optical connecting member 101, the MCF 102 as one example
of the optical element and the SCFs 103 as one example of the
optical component are optically connected to configure an optical
connecting structure C3. Note that the optical connecting member
101 may also be used to form the optical connecting structure C2
shown in FIG. 10.
[0088] The MCF 102 (optical element) is a fiber in which a
plurality of cores (optical I/O parts) are disposed in the same
clad so that their mutual optical axes become parallel. Preferably,
a plurality of cores of the MCF 102 are disposed so that the
inter-core distance thereof becomes equal, respectively. While the
core array may be a one-dimensional array in which a plurality of
cores are disposed linearly, for instance, the core array is
preferably a two-dimensional array such as a triangular lattice or
square array.
[0089] The MCF 102 of this embodiment is of a triangular
lattice-shaped two-dimensional array, with one core at the center
position of the clad and six cores around the center core at
60.degree. intervals; that is, a total of seven cores are disposed
at mutually regular intervals. For instance, when there is no
center core, a precise triangular lattice array is not formed, but
the present invention includes an array that realizes a triangular
lattice array upon assuming the existence of the center core.
[0090] Meanwhile, the SCFs 103 (optical components) are fibers
having a core of the same diameter as the MCF 102, and in which the
cladding diameter of at least the tip portion is reduced so as to
become equal to the inter-core distance of the MCF 102. An MT
connector 104 is mounted at the tip of the plurality of SCFs 103. A
tip face 104a of the MT connector 104 is provided with guide pins
105 for mounting the optical connecting member 101. The tips of
seven SCFs 103 are exposed horizontally in one line at a
predetermined pitch according to the number of cores of the MCF 102
between the guide pins 105.
[0091] The optical connecting member 101 comprises, as shown in
FIG. 13 and FIG. 14, a main body part 111 formed from plastic resin
such as polyphenylenesulfide (PPS) resin or polyetherimide (PEI)
resin which is used for configuring a standard optical connector, a
plurality of (in this example, seven) waveguide parts 112 provided
in the main body part 111, and first and second fixing components
120, 121 for fixing the respective ends of the plurality of
waveguide parts 112. The main body part 111 has a first end 113
including a first end face 113a to be connected to an end face of
the MCF 102, a second end 114 including a second end face 114a to
be connected to an end face of the SCFs 103, and an intermediate
part 115 positioned between the first end 113 and the second end
114.
[0092] The first end 113 has a cylindrical shape with the same
diameter as the outer diameter of a ferrule 107 into which the MCF
102 has been inserted, and the end face thereof is the first end
face 113a having a circular cross section. The length of the first
end 113 is, for example, 5 times or more of the core diameter of
the MCF 102. Meanwhile, the second end 114 is of a substantial
hexahedron shape, and the end face thereof is the second end face
114a having the same shape as the tip face 104a of the MT connector
104. As with the first end 113, the length of the second end 114
is, for example, 5 times or more of the core diameter of the MCF
102.
[0093] The second end 114 is provided with fitting holes 116 into
which the guide pins 105 of the MT connector 104 are fitted. The
intermediate part 115 has a shape which spreads toward the bottom
from the first end 113 side to the second end 114 side so as to
connect the cylindrical first end 113 and the substantially
rectangular second end 114. The main body part 111 may also be
formed from epoxy resin in substitute for the foregoing PPS and the
like.
[0094] More specifically, the waveguide part 112 is configured from
the through-holes 117 extending in the main body part 111 so as to
connect the first end face 113a and the second end face 114a, and
the SCFs 118 tightly disposed in through-holes 117. The SCFs 18 are
fibers similar to the SCFs 103, and the cladding diameter thereof
is reduced so as to become equal to the inter-core distance of the
MCF 102. The intermediate portion of the waveguide part 112 curves
gently along the shape of the main body part 111 between the first
end face 113a and the second end face 114a, and joins the connected
end 112A and the diverged end 112B.
[0095] The first fixing component 120 is, as shown in (a) of FIG.
17, a component having a hollow cylindrical shape, and fixes the
plurality of waveguide parts 112 on the first end 113 side so that
the connected end 112A of each of the plurality of waveguide parts
112 becomes parallel to each other. As a result of being fixed in
parallel as described above, each of the connected ends 112A of the
plurality of waveguide parts 112 which is connected to the first
end face 113a becomes a straight-line portion. The first fixing
component 120 is disposed in the main body part 111 so that the
foregoing straight-line portion is orthogonal to the first end face
113a. The term "orthogonal" as used in this embodiment shows, for
example, that the angle relative to the first end face 113a is
within a range of 90 degrees.+-.0.5 degrees, but it is obvious to a
person skilled in the art that the foregoing range can be increased
or decreased as needed according to the connecting precision by the
optical connecting member.
[0096] Moreover, the plurality of waveguide parts 112 are, as shown
in FIG. 15, arrayed two-dimensionally by the first fixing component
120 so as to correspond to the plurality of cores of the MCF 102 at
the connected end 112A. As shown in (a) of FIG. 17, an inner
peripheral face 120a of the first fixing component 120 has a
tapered part 120b which spreads outward on the side (second end
face 114a side) that is opposite to the first end face 113a, and
can be easily spread as the plurality of waveguide parts 112 head
toward the second end face 114a.
[0097] The second fixing component 121 is a component which takes
on a substantial hexahedron shape as shown in (b) of FIG. 17, and
is internally formed with seven through-holes 121a to 121g. The
second fixing component 121 fixes the plurality of waveguide parts
112 on the second end 114 side so that the diverged end 112B of
each of the plurality of waveguide parts 112 becomes parallel to
each other. As a result of being fixed in parallel as described
above, each of the diverged end 112B of the plurality of waveguide
parts 112 which is diverged to the second end face 114a becomes a
straight-line portion. The second fixing component 121 is disposed
in the main body part 111 so that the foregoing straight-line
portion is orthogonal to the second end face 114a. The plurality of
waveguide parts 112 are arrayed, as shown in FIG. 16,
one-dimensionally by the second fixing component 121 so as to
correspond to the plurality of cores of the SCFs 103 at the
diverged end 12B.
[0098] The first and second fixing components 120, 121 are formed,
for example, from metal, resin, ceramic or the like, and is
configured from a component for use in insert molding when the
optical connecting member 101 is manufactured via insert molding as
described later. While the first fixing component 120 may be formed
from any one of the foregoing materials, when the first fixing
component 120 is formed from zirconia, the operation of inserting
the SCFs 118 of the waveguide parts 112 into the first fixing
component 120 is facilitated, and this is even more preferable. The
length of the first and second fixing components 120, 121 and the
connected end 112A and the diverged end 112B is, for example, 3 to
5 times or more of the core diameter of the MCF 102.
[0099] As a result of being fixed by the first fixing component
120, one end face of the waveguide part 112 is exposed on the first
end face 113a so as to cause the core position of the MCF 102 and
the core position of the SCFs 118 to correspond, and, as shown in
FIG. 15, one core is disposed at the center position of the first
end face 113a and six cores are disposed around the center core at
60.degree. intervals; that is, a total of seven cores are disposed
at mutually regular intervals. As a result of being fixed by the
second fixing component 121, the other end face of the waveguide
part 112 is exposed on the second end face 114a so as to cause the
core position of the SCFs 103 and the core position of the SCFs 118
to correspond, and, as shown in FIG. 16, disposed horizontally in
one line at a predetermined pitch between the fitting holes
116.
[0100] With the optical connecting member 101 configured as
described above, in a state where the core position of the MCF 102
and the position of the waveguide parts 112 on the first end face
113a are matched, by causing the end face of the MCF 102 fixed by
the ferrule 107 and the first end face 113a of the main body part
111 to come into contact inside the split sleeve 119, and
additionally fitting the guide pins 105 into the fitting holes 116
of the second end 114 and causing the tip face 104a of the MT
connector 104 and the second end face 114a of the main body part
111 to come into contact, the MCF 102 and the plurality of SCFs 103
can be connected via the waveguide parts 112.
[0101] Here, with the optical connecting member 101, the connected
end 112A of each of the plurality of waveguide parts 112 which is
connected to the first end face 113a is a straight-line portion
that is orthogonal to the first end face 113a, and the connected
ends 112A are parallel to each other. In other words, the optical
axes of the plurality of waveguide parts 112 are parallel to each
other on the first end 113 side. Consequently, the optical axis of
the MCF 102 respectively having optical axes which are parallel to
each other and the connecting part of the waveguide parts 112 can
be matched easily.
[0102] The diverged end 112B which is diverged to the second end
face 114a is a straight-line portion that is orthogonal to the
second end face 114a, and the diverged ends 112B are parallel to
each other. In other words, the optical axes of the plurality of
waveguide parts 112 are parallel to each other on the second end
114 side. Consequently, the optical axis of the SCFs 103
respectively having optical axes which are parallel to each other
and of the connecting part of the waveguide parts 112 can also be
matched easily. Accordingly, in comparison to cases where light is
emitted obliquely from the first end face 113a and the second end
face 114a, or cases where the optical axis of the light from the
respective waveguide parts 112 is misaligned from each other,
optical connecting loss can be inhibited favorably according to the
optical connecting member 101.
[0103] The foregoing optical connecting member 101 can be formed,
for instance, via insert molding. In the foregoing case, foremost,
as shown in FIG. 18, seven SCFs 118 for configuring the waveguide
parts 112 are prepared. Moreover, the first and second fixing
components 120, 121 for fixing the ends of the SCFs 118 are
prepared.
[0104] Subsequently, as shown in FIG. 19, one end (portion
corresponding to the connected end 112A) of the SCFs 118 is
inserted into the first fixing component 120, and, based on the
first fixing component 120, one SCF 118 is disposed at the center
position of the inner periphery of the first fixing component 120
and six SCFs 118 are disposed around such center position at 60
degree intervals; that is, a total of seven SCFs 118 are disposed
at mutually regular intervals, and one end of each of the plurality
of SCFs 118 is retained so as to become parallel to each other.
This portion that is retained in parallel forms the straight-line
portion.
[0105] Next, as shown in FIG. 20, the other end (portion
corresponding to the diverged end 112B) if the SCF 118 having one
end that is fixed by the first fixing component 120 is inserted to
each of the through-holes 121a to 121g of the second fixing
component 121, and, based on the second fixing component 121, the
other end of each of the plurality of SCFs 118 is retained to be
parallel to each other. This portion that is retained in parallel
forms the straight-line portion. During the foregoing retention,
the SCFs 118 deform and curve gently from one end to the other end
due to elastic deformation.
[0106] Subsequently, as shown in FIG. 21, a pair of molds 131
having recessed parts 132 according to the shape of the main body
part 111 is prepared. The recessed parts 132 respectively
correspond to the shape of one half portion and to the shape of the
other half portion of the main body part 111 in the width
direction, and, when the molds 131 are closed, form a space S
(refer to FIG. 22) of the same shape as the main body part 111 in
the molds 131. The recessed parts 132 are provided with a reduced
diameter part 134 that is more on the tip side than the forming
position of the first end 113.
[0107] In addition, the SCFs 118 in which either end thereof is
fixed by the first and second fixing components 120, 121 are
disposed between the recessed parts 122 of the molds 131. Upon the
foregoing disposition, the first fixing component 120 is retained
by the inner peripheral face of the reduced diameter part 134.
Based on this retention, the first fixing component 120 is disposed
in the molds 131 so that the straight-line portion of one end of
the SCFs 118 is orthogonal to the first end face 113a after the
molding is complete. The second fixing component 121 is also
positioned relative to the recessed parts 122 by the same members.
Based on this positioning, the second fixing component 121 is
disposed in the molds 131 so that the straight-line portion of the
other end of the SCFs 118 is orthogonal to the second end face 114a
after the molding is complete.
[0108] In this state, as shown in FIG. 22, when the pair of molds
131 are closed and resin (molding material) is poured from a resin
pouring hole (not shown) of the molds 131, obtained is the optical
connecting member 101 in which the plurality of waveguide parts 112
configured from the SCFs 118 and the first and second fixing
components 120, 121 which respective fix the respective ends of the
waveguide parts 112 are formed inside the main body part 111. Note
that the transfer molding technique may also be used.
[0109] On the first end face 113a of the main body part 111
obtained above, as shown in FIG. 23, a convex part 135
corresponding to the shape of the reduced diameter part 134 will
remain. Accordingly, by removing the convex part 135 via grinding
or the like, the first end face 113a is formed. The second end face
114a of the main body part 111 may also be subject to similar
grinding or the like. Consequently, the optical connecting member
101 comprising the foregoing configuration is obtained. Note that
when the amount of protrusion of the convex part 135 is small (for
example, around the same length as the core diameter), the convex
part 135 may be left as is. This is because, even when connected
with the MCF 102 or SCFs 103, it is unlikely that the convex part
135 will become damaged. With the optical connecting member 101
according to this embodiment, since the waveguide parts 112
respectively have straight-line portions which are parallel to each
other at either end 113, 114, the parallelism thereof will not be
damaged even if grinding is performed to a certain extent.
[0110] As explained above, with the optical connecting member 101,
the first fixing component 120 fixes the plurality of waveguide
parts 112 so that the plurality of waveguide parts 112 are parallel
to each other on the first end 113 side. Consequently, since the
optical axis of the plurality of waveguide parts 112 becomes
parallel to each other on the first end 113 side, the optical axis
of the optical connecting member 101 and the optical axis of the
MCF 102 can be matched easily, and optical connecting loss can be
favorably inhibited. Moreover, with the optical connecting member
101, since each of the plurality of waveguide parts 112 comprises a
region which becomes parallel to each other on the first end 113
side, it is possible to maintain the parallelism of the waveguide
parts 112 even in cases where the connecting face of the optical
connecting member 101 is polished to a certain degree in order to
obtain a favorable connecting face.
[0111] Moreover, the optical connecting member 101 comprises a
second fixing component 121 for retaining the other end of the
plurality of waveguide parts 112 at the second end 114. Thus, based
on the second fixing component 121, it is also possible to fix the
plurality of waveguide parts 112 so that the plurality of waveguide
parts 112 are parallel to each other also on the second end 114
side. Consequently, since the optical axis of the plurality of
waveguide parts 112 becomes parallel to each other also on the
second end 114 side, the optical axis of the optical connecting
member 101 and the optical axis of the plurality of SCFs 103 can be
matched easily, and optical connecting loss can be more favorably
inhibited. Moreover, with this optical connecting member 101, since
each of the plurality of waveguide parts 112 comprises a region
which becomes parallel to each other on the second end 114 side, it
is possible to maintain the parallelism of the waveguide parts even
in cases where the connecting face of the optical connecting member
is polished to a certain degree in order to obtain a favorable
connecting face.
[0112] Moreover, with the optical connecting member 101, the first
and second fixing components 120, 121 are components for use in
insert molding. Thus, it is possible to easily produce the optical
connecting member 101 in which the positioning of the first and
second fixing components 120, 121 in the main body part 111 has
been performed with precision.
[0113] Moreover, with the optical connecting member 101, the
waveguide parts 112 are formed with the SCFs 118 having a cladding
diameter which is equal to the distance between the plurality of
cores of the MCF 102. Since the core array of the MCF 102 is
normally formed so that the inter-core distance becomes equal,
based on the foregoing configuration, waveguide parts 112 which are
arrayed in the same manner as the core array of the MCF 102 can be
easily obtained.
[0114] Moreover, with the optical connecting member 101, the end
face 113a on the first end 113 side has a substantial circular
shape. Thus, upon fixing the MCF 102 to a general-purpose
cylindrical ferrule 107, an end face of the MCF 102 and the first
end 113 of the optical connecting member 101 can be easily
connected via the sleeve 119.
[0115] Moreover, with the optical connecting member 101, the end
face of each of the waveguide parts 112 is arrayed at regular
intervals at the first end 113. Since the core array of the MCF 102
is normally configured as a two-dimensional array so that the
inter-core distance becomes equal, based on the foregoing
configuration, connecting with the MCF 102 is facilitated.
[0116] Moreover, with the foregoing manufacturing method of the
optical connecting member 101, provided is a step of retaining both
ends of the plurality of waveguide parts 112 so that the plurality
of waveguide parts 112 are mutually parallel in the fixing
components 120, 121. In addition, the plurality of waveguide parts
112 retained in parallel as described above and the fixing
components 120, 121 for fixing the plurality of waveguide parts 112
are disposed in the molds 131 and subject to insert molding. Thus,
with the manufactured optical connecting member 101, the optical
axis of the plurality of waveguide parts 12 becomes parallel to
each other at either end, and the optical axis of the optical
connecting member 101 and the optical axis of the MCF 102 and the
SCFs 103 can be easily matched, and the optical connecting loss can
be favorably inhibited.
[0117] The present invention is not limited to the foregoing
embodiment, and may be modified variously. For example, in the
foregoing second embodiment, while the first fixing component 120
had a cylindrical shape, as a guide part for matching and
connecting the optical axis of the plurality of cores of the MCF
102 and the optical axis of one end of each of the plurality of
waveguide parts 112, as shown in (a) of FIG. 24, it is also
possible to provide a notch face 122a in which a part of the outer
periphery is cut out to form a D-shaped cross section. In the
foregoing case, since the first fixing component 122 for fixing the
waveguide parts 112 will have the guide part matching the optical
axes, the optical axis of the MCF 102 and the optical axis of the
waveguide parts 112 can be more easily matched.
[0118] In the foregoing embodiment, while the fitting holes 116
were provided to the main body part 111 as guide parts for
connecting to the SCFs 103 so that the optical axis of the
plurality of SCFs 103 and the optical axis of the other end of the
plurality of waveguide parts 112 will match, as shown in (b) of
FIG. 24, fitting holes 124a, 124b comprising the foregoing function
may also be included in the second fixing component 124. In the
foregoing case, since the second fixing component for fixing the
waveguide part 112 will have the guide part for matching the
optical axes, the optical axis of the plurality of SCFs 103 and the
optical axis of the waveguide parts 112 can be more easily
matched.
[0119] In the foregoing embodiment, while the main body part 111
had a shape which spreads toward the bottom from the first end 113
side to the second end 114 side so as to connect the cylindrical
first end 113 and the substantially rectangular second end 114, as
shown in FIG. 25, the overall outer shape may also be a substantial
hexahedron. In the foregoing case, the configuration of the mold to
be used for the molding can be simplified.
[0120] In the foregoing embodiment, while the SCFs 118 having a
constant outer diameter were disposed in the through-holes 117 to
form the waveguide parts 112, as shown in FIG. 26, SCFs 138 in
which the core diameter 138a is constant, but the outer diameter
gradually increases may also be used as the waveguide parts 112.
With these SCFs 138, the smallest cladding diameter portion 138b is
formed on the first end 113 side, and portions 138c, 138d have a
diameter which increases toward the second end 114. At the portion
138d on the second end 114 side, a coated part 138e is formed
internally, and the core covered with this coated part extends from
the second end face 114a at a sufficient length (so-called
pigtail-type component).
[0121] Consequently, the SCFs 138 extending from the second end
face 114a of the optical connecting member 101 can be directly
connected with another optical device without a guide pin. In the
foregoing case, since there will be no connecting part between the
waveguide parts 112 and the second end face 114a of the SCFs 103
unlike the foregoing embodiments, there is no need for a
straight-line portion in which the diverged end 112B which diverges
to the second end face 114a is orthogonal to the second end face
114a.
[0122] In the foregoing embodiment, upon manufacturing the optical
connecting member 101, molding was performed after disposing the
SCFs 118 in the molds 131. However, as explained in the first
embodiment, after molding the main body part 111 by using a carbide
pin having the same shape as the SCFs 118, it is also possible to
remove the pin and thereby insert the SCFs 118 into the formed
through-holes 117.
[0123] Moreover, while the foregoing embodiment explained a case
where the first and second end faces 113a, 114a are formed to be
perpendicular to the optical axis of the MCF 102 or the SCFs 103,
in order to achieve a highly reflective optical connecting member,
these end faces 113a, 114a may be ground to be inclined 8 degrees
relative to the face that is perpendicular to the optical axis of
the MCF 102 or the SCFs 103. In the foregoing case also, with the
optical connecting member 101 according to this embodiment, since
the waveguide parts 112 are parallel at the respective ends 113,
114, the optical axis of the optical connecting member 101 and the
optical axis of the MCF 102 or the optical axis of the SCFs 103 can
be easily matched, and optical connecting loss can be favorably
inhibited.
INDUSTRIAL APPLICABILITY
[0124] According to the optical connecting member and the optical
connecting structure of the present invention, an optical element
including a plurality of optical I/O parts and another optical
component can be efficiently connected via a simple
configuration.
REFERENCE SIGNS LIST
[0125] 1 . . . optical connecting member, 2 . . . MCF, 3 . . . SCF,
12 . . . waveguide part, 12A . . . connected end, 12B . . .
diverged end, 13 . . . first end, 13a . . . first end face, 14 . .
. second end, 14a . . . second end face, 18 . . . SCF, 37, 47 . . .
through-hole, 38 . . . fluid, 48 . . . optical reflective film, C1,
C2, C3 . . . optical connecting structure, 101, 101A, 101B . . .
optical connecting member, 102 . . . MCF, 103 . . . SCF, 112 . . .
waveguide part, 112A . . . connected end, 112B . . . diverged end,
113 . . . first end, 113a . . . first end face, 114 . . . second
end, 114a . . . second end face, 118 . . . SCF, 120, 123 . . .
first fixing component, 121, 124 . . . second fixing component,
122a . . . notch face, 124a, 124b . . . fitting hole.
* * * * *