Optical waveguides – With disengagable mechanical connector – Optical fiber to a nonfiber optical device connector
Reexamination Certificate
2001-12-18
2004-05-25
Ullah, Akm Enayet (Department: 2874)
Optical waveguides
With disengagable mechanical connector
Optical fiber to a nonfiber optical device connector
C385S092000
Reexamination Certificate
active
06739762
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an optical device package of the type that houses various optical devices in a case and leads them off the case through optical fibers optically coupled therewith for external connection and, more particularly, to an optical device package that permits optical coupling of optical devices and fibers without involving their relative positioning to place their optical axes in accurate alignment.
FIG. 1
depicts the construction of a conventional optical device package. Reference numeral
10
denotes a case;
20
denotes optical devices;
30
denotes a substrate with the optical devices
20
mounted thereon,
40
a
,
40
b
denotes lens array panels mounted in opposite sidewalls of the case
10
and each having plural lens arrays
41
arranged in plural columns,
43
denotes spacers;
50
denotes single-mode optical fibers arranged in a tape-like form in this example, and
60
a
,
60
b
denotes optical connector ferrules attached to end portions of the optical fibers
50
.
The substrate
30
is usually a semiconductor substrate, on which the optical devices are mounted. The optical devices that can be housed in the case
10
are, for example, optical switches, light emitting elements, light receiving elements, and so forth.
Turning now to
FIG. 2
, a brief description will be given of an optical path configuration in the case where optical switches
20
are housed in the case
10
.
FIG. 2
is a diagrammatic showing of the optical switch structure. The substrate
30
has formed in its top surface a depression (not shown) of the same depth over the entire area thereof, in which hinge-supported vertically moving plates
21
are placed as shown. Mounted on each vertically moving plate
21
are mirrors M
1
, M
2
, M
3
and M
4
, which are disposed with their reflecting surfaces tilted at
45
degrees to the optical axes of the lenses
41
a
held in the lens array panel
40
a
,
40
a
. With voltage application to electrodes formed on the vertically moving plate
21
and the substrate
30
, the plate
21
moves down vertically to its surface due to electrostatic attractive force, bringing down the mirrors M
1
, M
2
, M
3
and M
4
and held at the down position.
In this example, the optical switch
20
switches between the state in which the plate
21
is in the up position where the mirrors M
1
and M
2
reflect incident light from an optical fiber
50
A for transfer to an optical fiber
50
B and the state in which the plate
21
is in the down position where the incident light from the optical fiber
50
A passes over the mirror M
1
, then impinges on and is focused by the corresponding one of the lenses
41
b
(not shown) of the lens array panel
40
b
on the side opposite the optical fiber
50
A and the focused light is launched into an optical fiber
50
C.
FIG. 2
shows the case where four such optical switches are housed in the case
10
. For details of this optical switch, refer to Japanese Patent Application Laid-Open Gazette 2000-121967.
The optical fiber
50
is a well-known single-mode optical fiber. The lenses
41
of the lens array panel
40
a
,
40
b
are optical fiber segments obtained by cutting, for example, a graded index optical fiber short and inserted in lens receiving holes made through a lens holding plate
42
.
In the lens array panel
40
there are mounted plural lens arrays arranged in columns. The optical connector ferrule
60
a
,
60
b
is held at such a position that it is aligned with that of the lens arrays which is in alignment with the optical axes of the optical devices
20
. This brings the optical axes of the optical fibers
50
into alignment with the optical axes of the optical devices
20
housed in the case. Thereafter, the optical connector ferrule
60
a
,
60
b
is bonded to the case
10
.
The conventional optical device package has the construction in which the optical axes of the optical fibers
50
supported to the optical connector ferrule
60
a
,
60
b
are optically coupled to the optical devices
20
through the lens array
40
a
,
40
b
mounted in the sidewalls
10
S
a
,
10
S
b
of the case
10
. Hence, when the optical connector ferrule
60
a
,
60
b
is attached to the case
10
, much time is required to make adjustments for bringing the optical axes of each optical fiber
50
held by the optical connector ferrule
60
a
,
60
b
into alignment with the optical axis of the corresponding lens
41
of the lens array
40
a
,
40
b
. This seriously impairs the productivity of the optical device package.
Moreover, it is also troublesome and time-consuming to make adjustments for placing the optical axes of the lenses
41
of the lens array
40
a
,
40
b
and the optical devices
20
in alignment with each other.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an optical device package that is free from the necessity for the positioning and hence is easy to fabricate.
The optical device package according to an aspect of the present invention comprises:
a substrate having mounted on its one side optical devices and having formed in said one side positioning parts for defining the positions of optical axes of the optical devices;
a case with the substrate housed therein;
an optical connector ferrule mounted in the case;
flexible optical waveguides held at one end in optical fiber receiving holes made in the optical connector ferrule and having the other ends extended into the case and positioned in the positioning parts to provide optical coupling between the flexible optical waveguides and the optical devices; and
a ferrule coupler provided on the end face of the optical connector ferrule externally of the case, for optically coupling optical fibers held in another optical connector ferrule to the flexible optical waveguides.
According to another aspect of the invention, the substrate is a semiconductor substrate and the positioning parts are V grooves cut in the semiconductor substrate in parallel to the optical axes of the optical devices.
According to another aspect of the invention, the flexible optical waveguides are each formed by a graded index optical fiber that focuses light emitted therefrom.
According to another aspect of the invention, the flexible optical waveguides are each formed by a TEC optical fiber that focuses light emitted therefrom.
According to another aspect of the invention, the ferrule coupler comprises pins projecting from one of the optical connector ferrules and pin receiving holes made in the other optical connector ferrule.
According to still another aspect of the invention, misalignments between the optical axes of the optical devices and the axes of the optical fiber receiving holes of the optical connector ferrule and their misorientations are accommodated by deforming the flexible optical waveguides.
With the optical device package structure of the present invention, the optical devices and the optical connector ferrule mounted in either of opposite sidewalls of the case are interconnected by flexible optical waveguides, and end portions of the flexible optical waveguides are positioned by the positioning parts formed on the part of the optical devices to provide optical coupling between the flexible optical waveguides and the optical devices. Hence, the positioning can be accomplished simply by placing and fixing the end portions of the flexible optical waveguides in the positioning parts—this permits easy fabrication of optical device packages.
Further, since each optical connector ferrule mounted in one sidewall of the case is provided with an optical connector ferrule coupler, another optical connector ferrule having connected thereto is automatically positioned relative to and connected to the optical connector ferrule mounted in the sidewall of the case. Accordingly, the present invention allows assembling of the optical device package without involving the positioning, and hence it permits easy assembling and fabrication of optical device packages with increased productivity.
REFERENCES:
patent: 575799
Imaki Osamu
Kaku Ryoji
Kato Yoshichika
Mase Takao
Mori Keiichi
Gallagher & Lathrop
Japan Aviation Electronics Industry Limited
Lathrop, Esq. David N.
Rahll Jerry T
Ullah Akm Enayet
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