Optical waveguides – With optical coupler – Particular coupling structure
Reexamination Certificate
2001-08-27
2004-04-06
Chowdhury, Tarifur R. (Department: 2871)
Optical waveguides
With optical coupler
Particular coupling structure
C385S046000
Reexamination Certificate
active
06718096
ABSTRACT:
CROSS-REFERENCE TO A RELATED APPLICATION
This application claims priority benefits of a prior filed Japanese application number 2001-137217, filed May 8, 2001.
BACKGROUND OF THE INVENTION
The present invention relates to a compact and multiple optical fiber coupler and, more particularly, to a compact and multiple optical fiber coupler of the type that plural optical fiber couplers having their stripped portions fused to each other and drawn or tapered together are integrally joined to a common substrate and enclosed in the same package or capsule. The invention also pertains to a method of making the compact and multiple optical fiber coupler.
A description will be given first, with reference to
FIG. 1
, of a prior art example which is a 2-by-2 fusion taper type optical fiber coupler indicated generally by
10
. In
FIG. 1
, stripped portions
12
a
and
12
b
of two optical fibers
11
a
and
11
b
are first aligned in parallel contacting relation and then fused together and drawn or tapered to form a coupler portion
13
, which is fixed onto the surface of a substrate
15
, and the whole of the fused-tapered coupler portion
13
including the substrate
15
is enclosed in the same package or capsule
16
. The stripped portions
12
a
and
12
b
are fused and drawn or tapered to form the fused-tapered coupler portion
13
by such a method as shown in FIG.
2
A. That is, the stripped portions
12
a
and
12
b
of the pair of optical fibers
11
a
and
11
b
clamped in parallel relation are firmly gripped between two pairs of spaced-apart pins P
1
a
, P
1
b
and P
2
a
, P
2
b
so that they are aligned in parallel contacting relation, and the intermediate parallel contacting portions of the stripped optical fibers are fused together by heating with the flame
21
of a gas burner and tapered to form the coupler portion
13
. Alternatively, the optical fibers
11
a
and
11
b
are arranged with their stripped portions
12
a
and
12
b
held in crossing relation and fusion-tapered into a coupler portion as shown in FIG.
2
B.
FIG. 3
shows an example of a two-in-one package optical fiber coupler in which two 2-by-2 fusion taper type optical fiber couplers
10
-
1
and
10
-
2
, produced separately by the method described above with reference to
FIG. 1
, are enclosed in a common package or capsule
160
.
FIG. 4
schematically depicts another prior art example of a multiple optical fiber coupler, which is a 2-by-4 tree optical fiber coupler in which three 2-by-2 optical fiber couplers
10
-
1
,
10
-
2
and
10
-
3
similar to that mentioned above in respect of
FIG. 1
are enclosed in the package
160
. The illustrated 2-by-4 tree optical fiber coupler is a multiple optical fiber coupler in which the fused-tapered coupler portions
13
-
1
and
13
-
2
of the two 2-by-2 optical fiber couplers
10
-
1
and
10
-
2
are arranged in parallel relation and inner adjacent stripped portions
12
b
-
1
and
12
a
-
2
are connected to stripped portions
12
a
-
3
and
12
b
-
3
of the 2-by-2 optical fiber coupler
10
-
3
, respectively. This multiple optical fiber coupler is also enclosed in the common package or capsule
160
.
Since the conventional multiple optical fiber coupler of
FIG. 3
has a construction that the two 2-by-2 fusion taper type optical fiber couplers
10
-
1
and
10
-
2
enclosed in the packages
16
-
1
and
16
-
2
, respectively, are housed in the one package
160
, the outer dimension of the package
160
is larger than the outer dimension of the 2-by-2 optical fiber coupler
10
of
FIG. 1
, approximately twice in diameter. For example, the package
16
in
FIG. 1
is about 3 mm in diameter and about 50 mm in length, whereas the package
160
in
FIG. 3
is around 6 mm in diameter and around 50 mm in length.
Also in the case of the conventional multiple optical fiber coupler of
FIG. 4
in which three 2-by-2 optical fiber couplers
10
each enclosed in the package
16
depicted in
FIG. 1
are connected as described above, the package
160
is approximately twice larger than the individual package
16
in length as well as in diameter.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a compact and multiple optical fiber coupler of the type that plural optical fiber couplers having their stripped portions fused together and tapered are integrally joined to the same substrate and enclosed in the same package so as to solve the above-mentioned problems of the prior art, and a method of making the compact and multiple optical fiber coupler.
The multiple optical fiber coupler according to the present invention comprises:
at least three optical fibers arranged adjacent one another;
at least two coupler portions formed by fusing and tapering at least two of said at least three optical fibers;
a substrate having fixedly arranged on one side thereof said at least two coupler portions; and
a package for enclosing said at least two coupler portions and said substrate;
wherein said at least two optical fibers are extended out of said package from said at least two coupler portions enclosed in said package.
The method of making a multiple optical fiber coupler having at least two coupler portions according to the present invention comprises the steps of:
(a) arranging in parallel relation more than two optical fibers each having a stripped portion so that said stripped portions of a first pair of those adjacent ones of said more than two optical fibers contact with each other to form a first mating alignment portion and that said stripped portions of a second pair of those adjacent ones of said more than two optical fibers whose one optical fiber differs from one of the optical fibers of said first pair contact with each other to form a second mating alignment portion at a distance from said first mating alignment portion in the direction of extension of said more than two optical fibers, and clamping said more than two optical fibers at opposite sides of said stripped portions;
(b) simultaneously heating and drawing all of said more than two optical fibers in a first area containing said first mating alignment portion to fuse said first mating alignment portion to form a first coupler portion;
(c) simultaneously heating and drawing all of said more than two optical fibers in a second area containing said second mating alignment portion to fuse said second mating alignment portion to form a second coupler portion;
(d) fixing said stripped portions of all of said more than two optical fibers, including said first and second coupler portions, to one side of a common substrate; and
(e) hermetically sealing said stripped portions, including said first and second coupler portions, and whole of said substrate in a package.
REFERENCES:
patent: 5664037 (1997-09-01), Weidman
patent: 5682453 (1997-10-01), Daniel et al.
patent: 5732173 (1998-03-01), Bylander et al.
patent: 5802224 (1998-09-01), Okuta et al.
Chowdhury Tarifur R.
Gallagher & Lathrop
Japan Aviation Electronics Industry Limited
Kim Richard
Lathrop, Esq. David N.
LandOfFree
Compact and multiple optical fiber coupler and method of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Compact and multiple optical fiber coupler and method of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Compact and multiple optical fiber coupler and method of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3236310