CA1257415A - Optical multiplexer/demultiplexer - Google Patents
Optical multiplexer/demultiplexerInfo
- Publication number
- CA1257415A CA1257415A CA000452260A CA452260A CA1257415A CA 1257415 A CA1257415 A CA 1257415A CA 000452260 A CA000452260 A CA 000452260A CA 452260 A CA452260 A CA 452260A CA 1257415 A CA1257415 A CA 1257415A
- Authority
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- Prior art keywords
- waveguides
- light beams
- substrate
- optical communication
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/10—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type
- G02B6/12—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind
- G02B6/12007—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings of the optical waveguide type of the integrated circuit kind forming wavelength selective elements, e.g. multiplexer, demultiplexer
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
- G02B6/29305—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide
- G02B6/29307—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide components assembled in or forming a solid transparent unitary block, e.g. for facilitating component alignment
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29304—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating
- G02B6/29305—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means operating by diffraction, e.g. grating as bulk element, i.e. free space arrangement external to a light guide
- G02B6/2931—Diffractive element operating in reflection
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/293—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means
- G02B6/29379—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device
- G02B6/2938—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals with wavelength selective means characterised by the function or use of the complete device for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Optical Integrated Circuits (AREA)
- Optical Communication System (AREA)
- Optical Couplings Of Light Guides (AREA)
Abstract
ABSTRACT
OPTICAL MULTIPLEXER/DEMULTIPLEXER
A diffraction grating wavelength division multiplexer/demultiplexer comprises a reflection-type diffraction grating (34), a lens (32), and a linear array of single mode optical fibre (31). An integrated optical, converging waveguide array (30) is inserted between the single mode fibres (31) and the lens (32).
This achieves close packing of the channels and hence more efficient filling of the available bandwidth than is otherwise possible with single mode fibres owing to their small core-to-cladding ratio.
OPTICAL MULTIPLEXER/DEMULTIPLEXER
A diffraction grating wavelength division multiplexer/demultiplexer comprises a reflection-type diffraction grating (34), a lens (32), and a linear array of single mode optical fibre (31). An integrated optical, converging waveguide array (30) is inserted between the single mode fibres (31) and the lens (32).
This achieves close packing of the channels and hence more efficient filling of the available bandwidth than is otherwise possible with single mode fibres owing to their small core-to-cladding ratio.
Description
5t~ ~ 1 S
R.A.LINKE 2 OPTICAL MULTIPLEXER/DEMULTIPLEXER
This invention relates to optical multiplexers and demultiplexers.
As the low-loss wavelength region of optical fibres has expanded, techniques for utili~ing this increased bandwidth by simultaneously transmitting several signals of different wavelengths along each fibre are being investigated. One such technique util;~es angularly dispersive devices such as gratings. (See, for example, "Optical Devices for Wavelength Multiplexing and Demultiplexing" by W.J.
Tomlinson; also see "High-capacity Wavelength Demultiplexer with a Large Diameter GRIN Rod Lens" by B.D. Metcalf et al.9 published in the March 1, 1982 issue of Applied Optics, Vol. 21, No. 5, pp. 794-796;
and "20-Channel Micro-ODtic Grating Demultiplexer for 1.1-1.6 ~m Band Using a Small Focusing Parameter Graded-Index Rod Lens" by M. Seki et al., published in the March 18~ 1982 issue of Electronics Letters, Vol. 18, No. 6, pp. 257-258).
Such devices typically comprise a fibre array, a lens and a grating. When used as a demultiplexer, a plurality of signals at different wavelengths enter the device along an input fibre, are collimated by the lens and directed onto the grating where they are dispersed as a function of wavelength. Each of the diffracted beams is then focused onto a different one of the remaining fibres. In ~his way the signals are spatially separated for subsequent independent processing. When operated in the reverse fashion, signals in each of the fibres can be multiplexed for simultaneous transmission along a common fibre.
Such devices are well suited for demultiplexing multimode and single mode signals. As noted by Tomlinson, however, they are not very efficient when used to multiplex single mode signals. The problem arises from the fact that in a single mode fibre the core diameter is small compared to the outside diameter of the cladding~
Consequently, close packing of the channels cannot be obtained~
resulting in inefficient use of the available bandwidth.
~57~L5 In accordance with an aspect of the invention there is provided an optical communication system, comprising:
first and second spatially separated light sources capable of emitting, respectively, first and second spatially separated light beams of different wavelengths; first means, capable of receiving said first and second light beams via a transmission medium other than a multimode optical fiber, for spatially combining said first and second light beams; second means, capable of receiving the spatially combined first and second light beams emanating from said first means, for s~atially separating the spatially combined first and second light beams; and first and second optical detectors for detecting, respectively, said first and second spatially separated light beams emanating from said second means, wherein said optical communication system further comprises a first substrate in optical communication with said transmission medium and said first means, said first substrate including a first and a second optical waveguide, said first and second waveguides including, respectively, first and second waveguiding strips embedded in said substrate, which serve to guide, respectively, said first and second spatially separated light beams emitted by said first and second light sources and transmitted by said medium, said first and second waveguides extending from a first end where said light beams enter said waveguides to a second end where said light beams exit said waveguides to subsequently impinge said first means, the spacing between said wave-guides at said second end being less than that at said first end, and a second substrate in optical communication with said second means, said second su~strate including a third and a fourth optical waveguide, said third and fourth waveguides including, respectively, third and fourth waveguiding strips embedded in said second substrate, which serve to guide, respectively, said first and second spatially separated light beams emanating from said second means, said th;rd and fourth waveguides extending from an - 2a - 1~ 574~LS
iput end where said light beams enter said third and ~ourth waveguides to an outp~t end where said light beams exit said third and fo~rth waveguides, the spacing between said third and fo~rth waveguides at said input end being less than that at said output end, and said second substrate including a groove at said input end between said third and ourth waveguiding strips and/or said third and fourth waveguides having unequal propagation constants.
Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings ~n which:-FIG. 1 shows a known reflection-type, diffraction grating multiPlexer/demultiplexer;
FIG. 2 included for purposes of explanation, shows the response characteristic of the multiplexer/demultiplexer of FIG. l;
FIG. 3 shows a mNltiplexer~demultiplexer embodying the present invention; and FIGS. 4 and 5 show portions of modified embodiments of the invention.
Referring to the drawings, FIG. 1 shows a known reflection-type, diffraction-grating, wavelength division multiplexer/demultiplexer 10.
For purposes of illustration and explanation, the device is shown operating as a demultiplexer comprising a common input multimode optical fibre 9, and a linear array of output multimode optical fibres 11-1. 11-2 ... 11-6. Signals at different wavelengths ~ 2 ... ~6, delivered by fibre 9, are spatially separated by means of a blazed, reflection-type diffraction grating 13. A lens 12, interposed between the fibre array and the grating, serves to focus the several optical beams.
In operations, wave energy at wavelengths ~ 2 ~6, emitted by fibre 9, is focused onto grating 13 from which it is selectively reflected. The resulting intensity distribution, as a function of distance D along the fibre array, is shown in FIG. 2.
Measured from some arbitrary reference point, O, the first intensity peak at wàvelength ~1 occurs at a distance D1 along the D
axis. Similarly, peaks at wavelengths ~2 ~3 - ~6 occur at distances d2 d3 ... d6 Thus~ the several ~7'~
components of the incident signal, each corresponding to a separate signal channel, can be spatially separated by placing a fibre at the focus point for each of the diffracted signals, as shown in FIG. 1.
Advantageously, the grating 13 is designed so that the distance D
between intensity peaks is equal to the outside d;ameter of the fibres. This makes for the most efficient use of the available optical bandwidth. The channel bandwidth is a function of the core diameter, c~ For multimode fibres, where the ratio of the core diameter to the cladding diameter is approximately 0.5, efficient use is thus made of the available bandwidth. By contrast, the core-to-cladding ratio for single mode fibres is very much lower. Typical core and cladding diameters are 8~m and 125um, respectively, so that the utilization efficiency is reduced from 50 percent to about 6 percent. What is re~uired is a means for increasing the packing density of the channels. This is accomplished by interposing a converging waveyuide array between the fibres and the reflecting grating, as shown on FIG.
3. More specifically, the multiplexer/demultiplexer comprises an array 31 of input/output fibre sections 31-1, 31-2 ... 31-n; an integrated optic converging waveguide array 30; a lens 32; and a bla~ed diffraction grating 34. Advantageously, each fibre section is terminated with a suitable connector (not shown) for making connection to the system fibres. In this illustrative embodiment, the lens 32 ;s a 1/4 pitch grin lens which can be more conveniently coupled to the waveguide array than a discrete lens. A wedge 33 is included for more efficient coupling between lens 32 and grating 34.
As indicated above, close packing of the signal channels is impossible using conventional single mode fibres owing to the small core-to-cladding ratio. The use of nonstandard single mode fibres with very thin claddings, and corresponding larger core-to-cladding ratio, would present formidable handling difficult;es. The use of an integrated waveguide array avoids both of these problems. As shown, each of the fibres 31-1, 31-2 ... 31-n is terminated at one end o~ one of the waveguides 30-1, 30-2 ... 31-n. The waveguide array converges so that at the lens end the spacing between waveguides is much smaller than the cladding diameter of the standard single mode fibre.
~'~5~4~5 Crosstalk will ultimately limit the waveguide packing density.
However, crosstalk is small for spacings of order twice the mode size and can be further reduced, if necessary, by placing grooves in the waveguide substrate between adjacent waveguides, as illustrated in FIG. 4. In this Figure, the end of the array adjacent to the lens is shown. For purposes of illustration, five waveguides 41, 42, 43, 44 and 45 are shown embedded in a suitable substrate 46. To more effectively isolate the several channels, grooves 50, 51, 52 and 53 are formed in substrate 46 in the region between adjacent waveguides.
Greater isolation can be realised by making the propagation constants of adjacent waveguides unequal~
The multiplexer described hereinabove can be integrated onto a common substrate. One dimensional focusing and diffraction techniques for thin-film optical waveguides have been demonstrated using glass substrates. The use of an electrooptically active substrate, such as LiNbO3 would also allow the integration of other circuit functions on the same substrate. For example, FIG. 5 shows a further modification of the waveguide array in which modulators 61-1, 61-2, 61-3 and 61-4 have been placed along the respective waveguides 60-1, 60-2, 60-3 and 60-4. In this embodiment, cw signals at wavelengths ~1 ~2 ~3 and ~4 are coupled into the waveguide array 60. The output along waveguide 65 comprises wavelength multiplexed, modulated signals.
R.A.LINKE 2 OPTICAL MULTIPLEXER/DEMULTIPLEXER
This invention relates to optical multiplexers and demultiplexers.
As the low-loss wavelength region of optical fibres has expanded, techniques for utili~ing this increased bandwidth by simultaneously transmitting several signals of different wavelengths along each fibre are being investigated. One such technique util;~es angularly dispersive devices such as gratings. (See, for example, "Optical Devices for Wavelength Multiplexing and Demultiplexing" by W.J.
Tomlinson; also see "High-capacity Wavelength Demultiplexer with a Large Diameter GRIN Rod Lens" by B.D. Metcalf et al.9 published in the March 1, 1982 issue of Applied Optics, Vol. 21, No. 5, pp. 794-796;
and "20-Channel Micro-ODtic Grating Demultiplexer for 1.1-1.6 ~m Band Using a Small Focusing Parameter Graded-Index Rod Lens" by M. Seki et al., published in the March 18~ 1982 issue of Electronics Letters, Vol. 18, No. 6, pp. 257-258).
Such devices typically comprise a fibre array, a lens and a grating. When used as a demultiplexer, a plurality of signals at different wavelengths enter the device along an input fibre, are collimated by the lens and directed onto the grating where they are dispersed as a function of wavelength. Each of the diffracted beams is then focused onto a different one of the remaining fibres. In ~his way the signals are spatially separated for subsequent independent processing. When operated in the reverse fashion, signals in each of the fibres can be multiplexed for simultaneous transmission along a common fibre.
Such devices are well suited for demultiplexing multimode and single mode signals. As noted by Tomlinson, however, they are not very efficient when used to multiplex single mode signals. The problem arises from the fact that in a single mode fibre the core diameter is small compared to the outside diameter of the cladding~
Consequently, close packing of the channels cannot be obtained~
resulting in inefficient use of the available bandwidth.
~57~L5 In accordance with an aspect of the invention there is provided an optical communication system, comprising:
first and second spatially separated light sources capable of emitting, respectively, first and second spatially separated light beams of different wavelengths; first means, capable of receiving said first and second light beams via a transmission medium other than a multimode optical fiber, for spatially combining said first and second light beams; second means, capable of receiving the spatially combined first and second light beams emanating from said first means, for s~atially separating the spatially combined first and second light beams; and first and second optical detectors for detecting, respectively, said first and second spatially separated light beams emanating from said second means, wherein said optical communication system further comprises a first substrate in optical communication with said transmission medium and said first means, said first substrate including a first and a second optical waveguide, said first and second waveguides including, respectively, first and second waveguiding strips embedded in said substrate, which serve to guide, respectively, said first and second spatially separated light beams emitted by said first and second light sources and transmitted by said medium, said first and second waveguides extending from a first end where said light beams enter said waveguides to a second end where said light beams exit said waveguides to subsequently impinge said first means, the spacing between said wave-guides at said second end being less than that at said first end, and a second substrate in optical communication with said second means, said second su~strate including a third and a fourth optical waveguide, said third and fourth waveguides including, respectively, third and fourth waveguiding strips embedded in said second substrate, which serve to guide, respectively, said first and second spatially separated light beams emanating from said second means, said th;rd and fourth waveguides extending from an - 2a - 1~ 574~LS
iput end where said light beams enter said third and ~ourth waveguides to an outp~t end where said light beams exit said third and fo~rth waveguides, the spacing between said third and fo~rth waveguides at said input end being less than that at said output end, and said second substrate including a groove at said input end between said third and ourth waveguiding strips and/or said third and fourth waveguides having unequal propagation constants.
Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings ~n which:-FIG. 1 shows a known reflection-type, diffraction grating multiPlexer/demultiplexer;
FIG. 2 included for purposes of explanation, shows the response characteristic of the multiplexer/demultiplexer of FIG. l;
FIG. 3 shows a mNltiplexer~demultiplexer embodying the present invention; and FIGS. 4 and 5 show portions of modified embodiments of the invention.
Referring to the drawings, FIG. 1 shows a known reflection-type, diffraction-grating, wavelength division multiplexer/demultiplexer 10.
For purposes of illustration and explanation, the device is shown operating as a demultiplexer comprising a common input multimode optical fibre 9, and a linear array of output multimode optical fibres 11-1. 11-2 ... 11-6. Signals at different wavelengths ~ 2 ... ~6, delivered by fibre 9, are spatially separated by means of a blazed, reflection-type diffraction grating 13. A lens 12, interposed between the fibre array and the grating, serves to focus the several optical beams.
In operations, wave energy at wavelengths ~ 2 ~6, emitted by fibre 9, is focused onto grating 13 from which it is selectively reflected. The resulting intensity distribution, as a function of distance D along the fibre array, is shown in FIG. 2.
Measured from some arbitrary reference point, O, the first intensity peak at wàvelength ~1 occurs at a distance D1 along the D
axis. Similarly, peaks at wavelengths ~2 ~3 - ~6 occur at distances d2 d3 ... d6 Thus~ the several ~7'~
components of the incident signal, each corresponding to a separate signal channel, can be spatially separated by placing a fibre at the focus point for each of the diffracted signals, as shown in FIG. 1.
Advantageously, the grating 13 is designed so that the distance D
between intensity peaks is equal to the outside d;ameter of the fibres. This makes for the most efficient use of the available optical bandwidth. The channel bandwidth is a function of the core diameter, c~ For multimode fibres, where the ratio of the core diameter to the cladding diameter is approximately 0.5, efficient use is thus made of the available bandwidth. By contrast, the core-to-cladding ratio for single mode fibres is very much lower. Typical core and cladding diameters are 8~m and 125um, respectively, so that the utilization efficiency is reduced from 50 percent to about 6 percent. What is re~uired is a means for increasing the packing density of the channels. This is accomplished by interposing a converging waveyuide array between the fibres and the reflecting grating, as shown on FIG.
3. More specifically, the multiplexer/demultiplexer comprises an array 31 of input/output fibre sections 31-1, 31-2 ... 31-n; an integrated optic converging waveguide array 30; a lens 32; and a bla~ed diffraction grating 34. Advantageously, each fibre section is terminated with a suitable connector (not shown) for making connection to the system fibres. In this illustrative embodiment, the lens 32 ;s a 1/4 pitch grin lens which can be more conveniently coupled to the waveguide array than a discrete lens. A wedge 33 is included for more efficient coupling between lens 32 and grating 34.
As indicated above, close packing of the signal channels is impossible using conventional single mode fibres owing to the small core-to-cladding ratio. The use of nonstandard single mode fibres with very thin claddings, and corresponding larger core-to-cladding ratio, would present formidable handling difficult;es. The use of an integrated waveguide array avoids both of these problems. As shown, each of the fibres 31-1, 31-2 ... 31-n is terminated at one end o~ one of the waveguides 30-1, 30-2 ... 31-n. The waveguide array converges so that at the lens end the spacing between waveguides is much smaller than the cladding diameter of the standard single mode fibre.
~'~5~4~5 Crosstalk will ultimately limit the waveguide packing density.
However, crosstalk is small for spacings of order twice the mode size and can be further reduced, if necessary, by placing grooves in the waveguide substrate between adjacent waveguides, as illustrated in FIG. 4. In this Figure, the end of the array adjacent to the lens is shown. For purposes of illustration, five waveguides 41, 42, 43, 44 and 45 are shown embedded in a suitable substrate 46. To more effectively isolate the several channels, grooves 50, 51, 52 and 53 are formed in substrate 46 in the region between adjacent waveguides.
Greater isolation can be realised by making the propagation constants of adjacent waveguides unequal~
The multiplexer described hereinabove can be integrated onto a common substrate. One dimensional focusing and diffraction techniques for thin-film optical waveguides have been demonstrated using glass substrates. The use of an electrooptically active substrate, such as LiNbO3 would also allow the integration of other circuit functions on the same substrate. For example, FIG. 5 shows a further modification of the waveguide array in which modulators 61-1, 61-2, 61-3 and 61-4 have been placed along the respective waveguides 60-1, 60-2, 60-3 and 60-4. In this embodiment, cw signals at wavelengths ~1 ~2 ~3 and ~4 are coupled into the waveguide array 60. The output along waveguide 65 comprises wavelength multiplexed, modulated signals.
Claims (5)
1. An optical communication system, comprising: first and second spatially separated light sources capable of emitting, respectively, first and second spatially separated light beams of different wavelengths; first means, capable of receiving said first and second light beams via a transmission medium other than a multimode optical fiber, for spatially combining said first and second light beams; second means, capable of receiving the spatially combined first and second light beams emanating from said first means, for spatially separating the spatially combined first and second light beams; and first and second optical detectors for detecting, respectively, said first and second spatially separated light beams emanating from said second means, wherein said optical communication system further comprises a first substrate in optical communication with said transmission medium and said first means, said first substrate including a first and a second optical waveguide, said first and second waveguides including, respectively, first and second waveguiding strips embedded in said substrate, which serve to guide, respectively, said first and second spatially separated light beams emitted by said first and second light sources and transmitted by said medium, said first and second waveguides extending from a first end where said light beams enter said waveguides to a second end where said light beams exit said waveguides to subsequently impinge said first means, the spacing between said waveguides at said second end being less than that at said first end, and a second substrate in optical communication with said second means, said second substrate including a third and a fourth optical waveguide, said third and fourth waveguides including, respectively, third and fourth waveguiding strips embedded in said second substrate, which serve to guide, respectively, said first and second spatially separated light beams emanating from said second means, said third and fourth waveguides extending from an input end where said light beams enter said third and fourth waveguides to an output end where said light beams exit said third and fourth waveguides, the spacing between said third and fourth waveguides at said input end being less than that at said output end, and said second substrate including a groove at said input end between said third and fourth waveguiding strips and/or said third and fourth waveguides having unequal propagation constants.
2. The optical communication system of claim 1 wherein said first means includes a lens and a diffraction grating, said lens being positioned between said second end and said diffraction grating to focus the light beams guided by, and emanating from, said first and second waveguides onto said diffraction grating.
3. The optical communication system of claim 1 wherein said first substrate includes electrooptic material.
4. The optical communication system of claim 1 further comprising means for amplitude modulating an optical signal in each of said first and second waveguiding strips.
5. The optical communication system of claim 1 wherein said second means includes a lens and a diffraction grating, said lens being positioned between said input end and said diffraction grating to focus said first and second light beams reflectively diffracted, and thus spatially separated, by said diffraction grating onto said third and fourth waveguides.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US48853783A | 1983-04-25 | 1983-04-25 | |
| US488,537 | 1983-04-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1257415A true CA1257415A (en) | 1989-07-11 |
Family
ID=23940052
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000452260A Expired CA1257415A (en) | 1983-04-25 | 1984-04-18 | Optical multiplexer/demultiplexer |
Country Status (8)
| Country | Link |
|---|---|
| JP (2) | JPS59210413A (en) |
| CA (1) | CA1257415A (en) |
| DE (1) | DE3414724A1 (en) |
| FR (1) | FR2544883B1 (en) |
| GB (1) | GB2139374B (en) |
| IT (1) | IT1176113B (en) |
| NL (1) | NL192171C (en) |
| SE (1) | SE454121B (en) |
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| GB8718560D0 (en) * | 1987-08-05 | 1987-09-09 | Gec Avionics | Nuclear pulse simulation |
| GB2219869B (en) * | 1988-06-15 | 1992-10-14 | British Telecomm | Optical coupling device |
| GB2251957B (en) * | 1990-11-29 | 1993-12-15 | Toshiba Kk | Optical coupler |
| DE4134293C1 (en) * | 1991-10-17 | 1993-02-11 | Messer Griesheim Gmbh, 6000 Frankfurt, De | |
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| CA2486725C (en) | 2002-05-20 | 2012-10-23 | Metconnex Canada Inc. | Reconfigurable optical add-drop module, system and method |
| CN100422777C (en) * | 2002-11-01 | 2008-10-01 | 欧姆龙株式会社 | Optical multiplexer/demultiplexer and production method for optical multiplexer/demultiplexer |
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| US10727945B1 (en) | 2019-07-15 | 2020-07-28 | GenXComm, Inc. | Efficiently combining multiple taps of an optical filter |
| US11215755B2 (en) | 2019-09-19 | 2022-01-04 | GenXComm, Inc. | Low loss, polarization-independent, large bandwidth mode converter for edge coupling |
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| US11796737B2 (en) | 2020-08-10 | 2023-10-24 | GenXComm, Inc. | Co-manufacturing of silicon-on-insulator waveguides and silicon nitride waveguides for hybrid photonic integrated circuits |
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| US12057873B2 (en) | 2021-02-18 | 2024-08-06 | GenXComm, Inc. | Maximizing efficiency of communication systems with self-interference cancellation subsystems |
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|---|---|---|---|---|
| US3986020A (en) * | 1975-09-25 | 1976-10-12 | Bell Telephone Laboratories, Incorporated | Common medium optical multichannel exchange and switching system |
| US4111524A (en) * | 1977-04-14 | 1978-09-05 | Bell Telephone Laboratories, Incorporated | Wavelength division multiplexer |
| JPS56126806A (en) * | 1980-03-11 | 1981-10-05 | Nec Corp | Diffraction grating type light branching filter |
| DE3239336A1 (en) * | 1982-10-23 | 1984-04-26 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Optical wavelength-division multiplexer |
-
1984
- 1984-04-18 SE SE8402180A patent/SE454121B/en not_active IP Right Cessation
- 1984-04-18 DE DE19843414724 patent/DE3414724A1/en active Granted
- 1984-04-18 CA CA000452260A patent/CA1257415A/en not_active Expired
- 1984-04-19 GB GB08410197A patent/GB2139374B/en not_active Expired
- 1984-04-20 FR FR848406282A patent/FR2544883B1/en not_active Expired - Fee Related
- 1984-04-20 IT IT20660/84A patent/IT1176113B/en active
- 1984-04-24 NL NL8401315A patent/NL192171C/en not_active IP Right Cessation
- 1984-04-25 JP JP59082099A patent/JPS59210413A/en active Pending
-
1993
- 1993-04-26 JP JP021518U patent/JPH0676907U/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| NL192171C (en) | 1997-02-04 |
| IT8420660A1 (en) | 1985-10-20 |
| IT8420660A0 (en) | 1984-04-20 |
| FR2544883B1 (en) | 1992-04-17 |
| SE454121B (en) | 1988-03-28 |
| DE3414724C2 (en) | 1993-07-22 |
| NL192171B (en) | 1996-10-01 |
| GB2139374A (en) | 1984-11-07 |
| FR2544883A1 (en) | 1984-10-26 |
| NL8401315A (en) | 1984-11-16 |
| JPH0676907U (en) | 1994-10-28 |
| JPS59210413A (en) | 1984-11-29 |
| SE8402180D0 (en) | 1984-04-18 |
| SE8402180L (en) | 1984-10-26 |
| GB8410197D0 (en) | 1984-05-31 |
| DE3414724A1 (en) | 1984-10-25 |
| GB2139374B (en) | 1986-07-16 |
| IT1176113B (en) | 1987-08-12 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |