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I claim:
1. A transmission and reception module for bidirectional optical message
and signal transmission, comprising:
a common housing forming an opening and containing lens coupling optics and
a fiber connection for an optical fiber with a longitudinal axis;
a first optical unit containing a transmitter disposed along the
longitudinal axis;
a second optical unit disposed adjacent the longitudinal axis, at least one
of said first optical unit and said second optical unit being a combined
transmission/reception unit having a unit housing at least partially
surrounding a transmitter and a receiver, the unit housing mounted in said
opening in said common housing; and
a beam splitter in said common housing disposed on the longitudinal axis
and at an oblique angle thereto, said beam splitter deflecting beams of
light radiation from and to said second optical unit.
2. The transmission and reception module according to claim 1, wherein said
combined transmission/reception unit includes a combined
mirror/beam-splitter layer equally reflecting a radiation beam emitted
from said transmitter and transmitting a received radiation beam to be
detected by said receiver.
3. The transmission/reception module according to claim 2, further
comprising:
a common substrate supporting said lens coupling optics and said
transmitter, said transmitter being a laser chip having a light output
side opposing a substrate part mounted on said common substrate, said
common substrate holding said combined mirror/beam-splitter layer, said
combined mirror/beam-splitter layer inclining at an angle of approximately
45.degree. to said light output side of said laser chip, such that a
radiation beam emitted by said light output side is reflected on said
combined mirror/beam-splitter layer toward said lens coupling optics; and
said substrate part and said common substrate transmitting a wavelength of
the received radiation beam to be detected by the receiver, and said light
receiver located on said outlet side of the received radiation beam from
said common substrate.
4. The transmission/reception module according to claim 1, wherein said
beam splitter contains a selective-wavelength filter.
5. The transmission/reception module according to claim 1, wherein said
transmission/reception unit further includes:
a common substrate having a bottom face and a substrate part, said
substrate part having a side surface with a mirror layer;
a laser chip below said optical coupling having a resonator surface
emitting a radiation and, said laser chip disposed as a transmitter with
said side surface adjacent said resonator surface, said resonator surfaces
inclined at an angle of approximately forty-five degrees to said side
surface for directing said radiation upwards perpendicularly from said
common substrate to said lens coupling optics, said lens coupling optics
attached to said substrate part, such that said mirror layer is adjacent
said resonator surface; said beam splitter reflecting the radiation
emitted from said laser chip and passing radiation injected from said lens
coupling optics such that said light receiver is provided underneath the
beam splitter, on said bottom face of said common substrate.
6. The transmission/reception module according to claim 1, further
comprising:
a reception unit.
7. The transmission/reception module according to claim 1, further
comprising:
a transmission unit.
8. The transmission/reception module according to claim 1, further
comprising:
a further transmission/reception unit.
9. The transmission/reception module according to claim 1, further
comprising:
two reception units.
10. The transmission/reception module according to claim 1, further
comprising:
a reception unit; and
a further transmission/reception unit.
11. The Transmission/reception module according to claim 1, further
comprising:
four reception units.
12. The transmission/reception module according to claim 1, further
comprising:
four transmission units.
13. The transmission/reception module according to claim 1, further
comprising:
four further transmission/reception units.
14. The transmission/reception module according to claim 1, further
comprising:
2n further transmission/reception units, where n.gtoreq.2.
15. A transmission and reception module for bidirectional optical message
and signal transmission, comprising:
a common housing forming at least two openings and containing lens coupling
optics and a fiber connection for an optical fiber with a longitudinal
axis;
a first optical unit containing a transmitter disposed along the
longitudinal axis being mounted in one of said at least two openings in
said common housing;
a second optical unit adjacent the longitudinal axis containing at least
one of a transmitter and a receiver, at least one of said first optical
unit and said second optical unit being a combined transmission/reception
unit integrated in a common unit housing, said common unit housing being
mounted in one of said at least two openings in said common housing; and
a beam splitter in said common housing disposed on the longitudinal axis
and at an oblique angle thereto, said beam splitter deflecting beams of
light radiation from and to said second optical unit.
16. The transmission/reception module according to claim 15, wherein said
transmission/reception unit further includes:
a common substrate having a bottom face and a substrate part, said
substrate part having a side surface with a mirror layer;
a laser chip below said optical coupling having a resonator surface
emitting a radiation and, said laser chip disposed as a transmitter with
said side surface adjacent said resonator surface, said resonator surfaces
inclined at an angle of approximately forty-five degrees to said side
surface for directing said radiation upwards perpendicularly from said
common substrate to said lens coupling optics, said lens coupling optics
attached to said substrate part, such that said mirror layer is adjacent
said resonator surface; said beam splitter reflecting the radiation
emitted from said laser chip and passing radiation injected from said lens
coupling optics such that an optical coupling for the light receiver is
provided underneath the beam splitter, on said bottom face of said common
substrate.
17. The transmission and reception module according to claim 16, wherein
said combined transmission/reception unit includes a combined
mirror/beam-splitter layer equally reflecting a radiation beam emitted
from said transmitter and transmitting a received radiation beam to be
detected by said receiver.
18. The transmission/reception module according to claim 17, further
comprising:
a common substrate supporting said lens coupling optics and said
transmitter, said transmitter being a laser chip having a light output
side opposing a substrate part mounted on said common substrate, said
common substrate holding said combined mirror/beam-splitter layer, said
combined mirror/beam-splitter layer inclining at an angle of approximately
45.degree. to said light output side of said laser chip, such that a
radiation beam emitted by said light output side is reflected on said
combined mirror/beam-splitter layer toward said lens coupling optics; and
said substrate part and said common substrate transmitting a wavelength of
the received radiation beam to be detected by the receiver, and an optical
coupling for said light receiver located on said outlet side of the
received radiation beam from said common substrate.
19. The transmission/reception module according to claim 15, wherein said
beam splitter contains a selective-wavelength filter.
20. The transmission/reception module according to claim 15, further
comprising a reception unit. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a transmission and reception module for
bidirectional optical message and signal transmission, in which a fiber
connection for an optical fiber and lens coupling optics are disposed in a
common housing. Such modules include a first optical unit, which contains
a transmitter, is disposed on the longitudinal axis of the housing defined
by the fiber axis. Such modules include at least one beam splitter
disposed at an oblique angle to the longitudinal axis, and on the
longitudinal axis, in the interior of the housing. By means of the beam
splitter, it is possible to deflect beams of light radiation from and to
at least one corresponding further optical unit. These optical units
disposed to the side of the longitudinal axis. For many years, fiber-optic
message transmission used transmission of at least one channel in each
case, bidirectionally, using the full-duplex or half-duplex method. By way
of example, European Patent Application 0 463 214 A1 discloses a
transmission and reception module, which is known as a BIDI module, for
bidirectional optical message and signal transmission. In this module, the
two active components (the light transmitter and the light receiver) are
installed as autonomous components encapsulated such that they are
hermetically sealed in a common module housing. In a hollow interior of
the common module housing, a beam splitter and lens coupling optics are
disposed. The module also includes a fiber connection for a common optical
fiber. The transmitter injects an optical signal into the attached glass
fiber, while another optical signal can be received from the same fiber
simultaneously or at a different time. The beam splitter separates the two
signals. The beam splitter also may contain a WDM (wavelength division
multiplexing) filter, in which one specific wavelength can be reflected,
and another can be passed.
If, apart from the respective one channel in each direction, it is intended
to transmit a further channel in at least one direction, then an external
fiber splitter or an external WDM filter can be installed in the supplying
glass fiber. This glass fiber can be located upstream of the module.
However, this represents a relatively impracticable solution.
On the other hand, a so-called multichannel transceiver module is proposed
in German Published, Non-Prosecuted Patent Application DE 93 114 859 A1.
In this application, at least one further light transmitter and/or light
receiver with associated lens coupling optics and at least one further
beam splitter are provided in the common housing of a conventional BIDI
module as described above. The further light transmitter or transmitters
and/or light receiver or receivers is or are designed preferably in the
form of the so-called TO (transistor outline) standard construction. TO
standard construction has been described in German Published,
Non-Prosecuted Patent Application DE 93 120 733 A1. However, this solution
has the disadvantage that bidirectional transmission of a further channel
requires two TO modules, namely a transmission module and a reception
module, in the common housing.
European Patent Application 0 644 668 A1 discloses a transmission and
reception module for bidirectional optical multichannel transmission
having a light transmitter, a light receiver, a fiber connection for a
common optical fiber, lens coupling optics, and a beam splitter. The beam
splitter is positioned at an intermediate point in the beam path, and is
disposed in a common housing. At least one further light transmitter
and/or light receiver, with associated lens coupling optics, and at least
one further beam splitter are provided in the common housing. In the
illustrated exemplary embodiments, the beam splitters are disposed one
behind the other in the beam path, and parallel to one another, inclined
at an angle of 45.degree. to the beam path, between the fiber connection
and the opposite light transmitter, in the axial direction of the optical
fibers in the housing.
European Patent Application 0 487 391 A1 relates to an optical
bidirectional transmission and reception module having a common fiber
connection opening, a plurality of transmitters, a plurality of receivers,
and a corresponding plurality of light paths. Beam splitters are in each
case disposed upstream of the transmitters and receivers in two mutually
parallel levels. The object of this arrangement of beam splitters is to
allow light at a wavelength corresponding to the respective transmitter or
receiver to pass, and to reflect light at all other wavelengths.
A compact bidirectional transmission and reception device is disclosed in
U.S. Pat. No. 5,416,624. The compact bidirectional transmission and
reception device has a planar convex lens with a beam-splitting wavelength
filter disposed on its planar surface. This lens is positioned between a
transmitter and a receiver. This arrangement produces a compact
transmission and reception device. In addition, in FIG. 4, this document
shows a linear array of such lenses, by means of which radiation beams
from such a linear arrangement of transmitters can be injected into a
linear arrangement of optical fibers.
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to specify a
transmission and reception module having a multichannel capability for
bidirectional optical message and signal transmission. This reception
module also is designed to save space and expand by adding further
bidirectional channels in as simple a manner as possible.
With the foregoing and other objects in view, there is provided, in
accordance with the invention, a transmission and reception module for
bidirectional optical message and signal transmission. This module
features a common housing forming an opening and containing lens coupling
optics and a fiber connection for an optical fiber with a longitudinal
axis. The module also includes a first optical unit containing a
transmitter disposed along the longitudinal axis. In addition, the modules
includes a second optical unit adjacent the longitudinal axis, at least
one of said first optical unit and said second optical unit being a
combined transmission/reception unit having a unit housing at least
partially surrounding a transmitter and a receiver, the unit housing
mounted in said opening in said common housing. The module further
includes a beam splitter in said common housing disposed on the
longitudinal axis and at an oblique angle thereto. The beam splitter
deflects beams of light radiation between said first optical unit and said
second optical unit.
The invention described further below with reference to exemplary
embodiments achieves this object in a compact module in which at least one
transmitter and at least one receiver are combined in a
transmission/reception unit. This unit is installed in the common housing.
Furthermore, at least one additional such transmission/reception unit or
at least one transmission unit or one reception unit are provided in the
common housing.
In one preferred embodiment of the present invention, the
transmission/reception unit is designed in accordance with a bidirectional
transceiver module which is described in German Published, Non-Prosecuted
Patent Application DE 93 120 733 A1 and is also referred to as a TO-BIDI
module. Furthermore, the at least one transmission unit or the at least
one reception unit is preferably designed as a TO module. The invention
thus describes a compact module that combines the assemblies of the known
BIDI module and those of the TO-BIDI module with their characteristics.
The multichannel BIDI thereby produced can transmit one channel, or more
than one channel, in the respective directions simultaneously, in addition
to the normal bidirectional function on two bidirectional channels.
A conventional BIDI module having two bidirectional channels, that is to
say one transmission channel and one reception channel, thus becomes a
module with three channels by the use of a TO transmission or reception
module by means of a TO-BIDI having the same external dimensions. If one
TO transmission module is replaced by a TO-BIDI, one transmission and
reception channel and a second reception channel result. If one TO
reception module is replaced by a TO-BIDI, the configuration produces two
transmission channels and one reception channel. Finally, if a TO laser
and TO receiver are each replaced by TO-BIDIs, then the configuration
produces two transmission and two reception channels: i.e., four channels.
This can, of course, also be expanded to the module arrangement having
three TO components, resulting in modules with five and six channels. The
corresponding expansion to even more channels can be achieved by
appropriate lengthening of the module by simultaneous outputting by means
of additional filters in the optical beam path to the corresponding
additional TO components. In optical terms, this can be done in a
particularly simple manner by designing the optics of the TO components
for one collimated beam in the module. The maximum possible number of
channels is thus twice as great as the number of connected TO-BIDIs, or is
correspondingly less if a single TO transmission or reception component is
used instead of a TO-BIDI.
A further major advantage of the arrangement according to the invention is
that the optical channel separations in the TO-BIDI and BIDI module can be
of a different type or of the same type. If, for example, a WDM filter is
used for virtually no-loss separation of two wavelengths in the module,
then not only can the separation in the TO-BIDI be accomplished in the
same way once again, using a WDM filter to two further wavelengths.
However, a 3 dB-beam splitter can also be used to split the intensity of
one wavelength between, in each case, one reception channel and one
transmission channel.
This means that the use of TO-BIDIs as TO components allows the
multichannel BIDI to operate each individual channel bidirectionally. This
is true particularly in the case of WDM systems having a number of
discrete wavelengths: for example, in accordance with the ITU Standard,
four wavelengths or even more. These are so-called HD-WDM systems. In
comparison with multichannel HD-WDM systems as normally used until now,
and which are operated only unidirectionally, this results in full
bidirectional functionality on each WDM channel. This means that, for
relatively recent multichannel WDM transmission on individual glass
fibers, the arrangement according to the invention allows the transmission
capacity of the fibers to be doubled by means of bidirectional operation.
Thus, using the arrangement according to the invention, two bidirectional
module types with different optics are combined such that a new module
type is produced. The functional characteristics of this new module are
considerably better than the intrinsic functions of the individual module
types. Thus, using the arrangement according to the invention, it is not
just possible to produce any desired multichannel modules, but also to
operate one-directional multichannel HD-WDM transmission systems fully
bidirectionally. The wavelength stabilization which is required, for
example by means of temperature stabilization, can in this case be
accomplished by appropriate temperature stabilization of the entire
module, as described, for example, in German Published, Non-Prosecuted
Patent Application DE 93 114 860 A1.
In accordance with another feature of the invention, the combined
transmission/reception unit includes a combined mirror/beam-splitter layer
equally reflecting a radiation beam emitted from the transmitter and
transmitting a received radiation beam that is to be detected by the
receiver.
In accordance with another feature of the invention, the
transmission/reception module further includes a common substrate
supporting the lens coupling optics and the transmitter. The transmitter
is a laser chip having a light output side opposing a substrate part
mounted on the common substrate. The common substrate holds the combined
mirror/beam-splitter layer. The combined mirror/beam-splitter layer
inclines at an angle of approximately forty-five degrees (45.degree.) to
the light output side of the laser chip such that a radiation beam which
is emitted by the light output side is reflected on the combined
mirror/beam-splitter layer toward the lens coupling optics. The substrate
part and the common substrate transmit a wavelength of the received
radiation beam to be detected by the receiver, and the light receiver
located on the outlet side of the received radiation beam from the common
substrate.
In accordance with another feature of the invention, the beam splitter can
contain a selective-wavelength filter.
In accordance with another feature of the invention, the
transmission/reception unit further includes a common substrate having a
bottom face and a substrate part. The substrate part having a side surface
with a mirror layer. The transmission/reception unit also includes a laser
chip below the optical coupling having a resonator surface emitting a
radiation and. The laser chip is disposed as a transmitter with the side
surface adjacent the resonator surface. The resonator surface inclines at
an angle of approximately forty-five degrees (.about.45.degree.) to the
side surface so the radiation is directed upwards perpendicularly from the
common substrate to the lens coupling optics. The lens coupling optics
attaches to the substrate part such that the mirror layer is adjacent the
resonator surface. The beam splitter reflects the radiation emitted from
the laser chip and passing radiation injected from the lens coupling
optics such that the light receiver is provided underneath the beam
splitter, on the bottom face of the common substrate.
In accordance with another feature of the invention, the
transmission/reception module can include a reception unit; a transmission
unit; a further transmission/reception unit; two reception units; a
reception unit and a further transmission/reception unit; four reception
units; four transmission units; and/or four further transmission/reception
units.
In accordance with another feature of the invention, the
transmission/reception module can include 2n further
transmission/reception units, where n is an integer greater than or equal
to 2.
Although the invention is illustrated and described herein as embodied in a
bidirectional module for multichannel use, it is nevertheless not intended
to be limited to the details shown, since various modifications and
structural changes may be made therein without departing from the spirit
of the invention and within the scope and range of equivalents of the
claims.
The construction and method of operation of the invention, however,
together with additional objects and advantages thereof will be best
understood from the following description of specific embodiments when
read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
FIG. 1 is a plan view of a basic embodiment of a multichannel BIDI;
FIG. 2a is a plan view of a multichannel BIDI with three TO components
wherein both of the subcomponents are TO receivers;
FIG. 2b is a plan view of a multichannel BIDI with three TO components
herein both of the subcomponents are TO receivers;
FIG. 3a is a plan view of a multichannel BIDI with five TO components
wherein four TO receivers are disposed at the side and one TO-BIDI is
disposed in the axial direction;
FIG. 3b is a plan view of a multichannel BIDI with five TO components
wherein four TO transmitters are disposed at the side, and one TO-BIDI is
disposed in the axial direction as a corresponding HDWDM transmitter;
FIG. 3c is a plan view of a multichannel BIDI with five TO components
wherein four TO-BIDIs are disposed at the side and one TO-BIDI is disposed
in the axial direction for the monitoring channel;
FIG. 4 is a plan view of a multichannel BIDI with n TO-BIDIs; and
FIG. 5 is f plan view of a transmission/reception unit in the form of a
TO-BIDI.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the figures of the drawings in detail and first,
particularly, to FIG. 1 thereof, there is seen a basic embodiment of the
present invention. The basic version of a multichannel BIDI is formed from
the common housing body 100, two (2) subcomponents 10 and 20 and the
common SM (single mode) connecting fiber 0. The lens coupling optic 110
for the common optical fiber 0 is disposed in the vicinity of the end of
the optical fiber 0 in the form of a spherical lens, although this may
also be omitted if the overall coupling optics are appropriately designed.
The subcomponent 10, which is fitted on the module axis, is a
transmission/reception unit that contains a transmitter and a receiver.
This transmission/reception unit may, for example, be a TO-BIDI module as
mentioned above. That is to say, it may be a bidirectional
transmission/reception unit produced using the standard TO construction
mentioned above and as described in German Patent Application No. 931 20
733.6. Such a bidirectional transmission/reception unit has a full
bidirectional function for a reception channel A, for example for 1480 nm,
and a transmission channel, for example for 1300 nm. The subcomponent 20
is installed in the common housing 100. The subcomponent 20 is a TO-PIN
diode in the illustrated exemplary embodiment. That is to say, a diode
receiver is likewise produced using the standard TO construction mentioned
above, for a further reception channel B that, for example, is set to a
wavelength of 1550 nm. The fully selective-wavelength channel separation
with an efficiency greater than ninety-five percent (>95%) in each case
is carried out for the further reception channel B using an appropriate
WDM filter. The WDM filter is contained in the beam splitter 22, on the
beam axis, using conventional BIDI technology. A stop filter 21 can also
be placed upstream of the TO housing of the subcomponent 20, in order to
mask out undesirable wavelengths.
The corresponding channel separation for the transmission channel and the
reception channel A within the subcomponent 10 can be provided using the
known TO-BIDI technology. An example of this technology is described in
German Patent Application No. 931 20 733.6, mentioned above.
The essential elements of this construction will be described once again
here, with reference to FIG. 5 in order to assist understanding. FIG. 5
shows a bidirectional transmission and reception module using TO
construction (TO-BIDI module) that can be used as the subcomponent 10. The
transmission and reception module essentially includes a laser chip 1,
which has lens coupling optics 6, as a light transmitter, a light receiver
8, and a beam splitter 9 disposed at an intermediate point in the beam
path. In addition, the beam splitter 9 is at least partially surrounded by
a housing 7 onto which a light inlet and outlet window 11 is glazed. The
laser chip 1 is disposed on a common substrate 2 composed of silicon. The
common substrate can be a submount mounted, for example, on a baseplate 19
of a TO housing. The laser chip 1 is disposed on the common substrate
between two substrate parts 3, 4. The side surfaces of the two substrate
parts 3,4 are adjacent the optical resonator surfaces of the laser chip 1,
are provided with mirror layers 5, and are inclined at an angle of
approximately forty-five degrees (45.degree.) to the resonator surfaces.
This angle of inclination provides that the coherent radiation emitted
from the laser chip 1 is deflected upwards, virtually at right angles to
the surface of the common substrate 2, as a divergent light beam onto the
lens coupling optics 6, which are disposed above the laser chip 1. The two
substrate parts 3, 4 are preferably composed of glass or (like the
substrate 2) of silicon, and have a trapezoidal profile. The lens coupling
optics 6 are disposed and mounted on at least one substrate part, in this
exemplary embodiment on the substrate part 3, such that the radiation
emitted from the laser chip 1 strikes it virtually at right angles.
The mirror layer 5 is adjacent the front face of the laser chip 1. The
mirror layer 5 is provided with a beam splitter 9 that reflects the
radiation emitted from the laser chip 1 and passes the radiation injected
from the exterior via the lens coupling optics 6. The light receiver 8 or
an optical coupling for the light receiver 8 is provided underneath the
beam splitter 9, on the bottom face of the common substrate 2.
The beam splitter 9 forms an optical separating device for different light
wavelengths or for the same light wavelengths. A separation of greater
than ninety-five percent (>95%) can be achieved for different light
wavelengths in the transmission path and reception path, that is to say
when the beam splitter is operated on a selective-wavelength basis. Fifty
percent (50%) separation, for example, or some other separation, can be
set if the wavelength in the two paths is the same. In order to achieve
bidirectional transmission, only the mirror layer 5, which is adjacent the
front face of the laser chip 1 and is mounted on the substrate part 3,
need be provided with a filter layer as a beam splitter 9. The beam
splitter 9 reflects the laser light at a wavelength emitted from the laser
and passes the light at a different wavelength that is incident from the
exterior. Silicon is transparent to light at a wavelength of more than 1.1
.mu.m. Silicon is also sufficient to fit a suitable light receiver 8 or a
suitable optical coupling for an external light receiver at the point
where the light emerges on the bottom face of the common substrate 2. The
substrate is preferably composed of silicon.
Such a TO-BIDI module, which is described in FIG. 5, may be used in the
transmission/reception module according to the invention as the
transmission/reception unit or as the subcomponent 10 as shown in FIG. 1.
However, any other conceivable configuration of a transmission/reception
unit may also be used as the subcomponent 10.
The beam splitter 22 also may separate the reception channel B without any
wavelength selectivity. In this case, it would be expedient to use an
approximately 5 dB beam splitter as the beam splitter 22 in the main beam
path. Such a beam splitter extracts approximately thirty percent
(.about.30%) for the subcomponent 20 and passes sixty percent (60%) which
is then split, for example, with 3 dB in the TO-BIDI module 10.
For the module arrangement according to the invention and as shown in FIG.
1, this results in the following first possible directional operating
condition range for three (3) transmission channels:
1a.) If three (3) wavelengths are used (for example 1300 nm, 1480 nm, and
1550 nm), full-duplex operation on three (3) channels with greater than
ninety-five percent (>95%) efficiency for the individual channels and
>35 dB channel separation.
1b.) If two (2) wavelengths are used (for example 1300 nm and 1550 nm),
full-duplex operation on one reception channel and one transmission
channel with greater than ninety-five percent (>95%) efficiency and
>50 dB channel separation for the reception channel (for example at
1550 nm), and half-duplex operation in each case for the second reception
channel and the transmission channel, in each case at an efficiency of,
for example, approximately fifty percent (.about.50%) (for example at 1300
nm).
1c.) If one (1) a wavelength is used (for example 1300 nm, or 1550 nm),
half-duplex operation on all three (3) channels (for example two (2)
reception channels and one (1) transmission channel), for example at an
efficiency of approximately thirty percent (-30%), distributed uniformly
between all the channels, or with the capability to split this in any
other ratio.
The second range of application or operation options for three (3) channels
is provided in the arrangement according to the invention if the TO
component disposed at the side of the module body is a TO laser instead of
a TO-PIN diode, and whose emission characteristic is matched to the module
optics. The options may be derived in a corresponding manner from 1a), b),
c).
The third range of application and operating options for even four (4)
channels is obtained in the arrangement according to the invention and as
shown in FIG. 1 if both the TO components disposed on the module housing
(on the side and on the axis) are TO-BIDIs. In this embodiment, two (2)
double channels are then respectively separated by one beam splitter on
the optical beam axis and one beam splitter in each of the TO-BIDIs. The
variation options can in this case once again be derived analogously to
the pattern specified above, expanded by one channel. The option of
full-duplex transmission on four (4) channels (for example 1280 nm, 1380
nm, 1480 nm, and 1560 nm) should be stressed in particular in this case.
FIGS. 2a and 2b show further exemplary embodiments of the arrangement
according to the invention having three (3) TO components 10, 20 and 30
and an SM connecting fiber 0 on the common module housing. The TO
component 10 is a TO-BIDI, and the two (2) other TO components 20 and 30
are either TO lasers and/or TO-PIN diodes or else TO-BIDIs. The additional
beam splitter 32 allows at least a portion of the radiation coming from
the connecting fiber 0 to be deflected in the direction of the TO
component 30. This beam splitter may also contain a selective-wavelength
filter. The range of operating and application options described with
reference to FIG. 1 thus results in 3 to 6 possible transmission channels.
In FIG. 2a, both the subcomponents 20 and 30 are TO receivers. Stop filters
21 and 32 can be connected upstream of the TO housings of both
subcomponents.
In FIG. 2b, the two subcomponents 10 and 30 are illustrated as TO-BIDIs.
FIGS. 3a, b, c show exemplary embodiments of the arrangement according to
the invention with five (5) TO components 10, 20, 30, 40, and 50 and one
(1) SM connecting fiber 0 on the common module housing 100. The beam
splitters 42 and 52 produce at least partial beam deflection in the
direction of the subcomponents 40 and 50. At least one of the TO
components is a TO-BIDI or, in the same sense any desired variants of
transmitters, receivers or TO-BIDIs. This thus results in an overall
maximum of ten (10) bidirectional transmission channels if fully equipped
with TO-BIDIs. The following variants should be stressed as being
particularly important in this version:
I) In the first variant, four (4) TO receivers are disposed at the side and
one (1) TO-BIDI is disposed in the axial direction. In this case, for
example, the HDWDM filters, matched to the ITU grid, can separate the four
(4) reception channels in the 1550 nm window, and the module can thus
receive four (4) channels. The TO-BIDI, disposed in the axial direction,
can in this case operate the monitoring channel in the 1300 nm window, or
bidirectionally at 1480 nm (FIG. 3a).
II) In the second variant, four (4) TO transmitters are disposed at the
side, and one (1) TO-BIDI is disposed in the axial direction as a
corresponding HDWDM transmitter, as the inverse of I. See FIG. 3b.
III) In the third variant, four (4) TO-BIDIs are disposed at the side and
one (1) TO-BIDI is disposed in the axial direction for the monitoring
channel, as a fully bidirectional HDWDM multichannel
transmission/reception component | | |
