[go: up one dir, main page]

WO1996009727A1 - Commutateur optique a barres croisees - Google Patents

Commutateur optique a barres croisees Download PDF

Info

Publication number
WO1996009727A1
WO1996009727A1 PCT/GB1995/002245 GB9502245W WO9609727A1 WO 1996009727 A1 WO1996009727 A1 WO 1996009727A1 GB 9502245 W GB9502245 W GB 9502245W WO 9609727 A1 WO9609727 A1 WO 9609727A1
Authority
WO
WIPO (PCT)
Prior art keywords
array
input
illumination
crossbar switch
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.)
Ceased
Application number
PCT/GB1995/002245
Other languages
English (en)
Inventor
William Alden Crossland
Robert Joseph Mears
Stephen Thomas Warr
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lynxvale Ltd
Cambridge University Technical Services Ltd CUTS
Original Assignee
Lynxvale Ltd
Cambridge University Technical Services Ltd CUTS
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Lynxvale Ltd, Cambridge University Technical Services Ltd CUTS filed Critical Lynxvale Ltd
Priority to AU35278/95A priority Critical patent/AU3527895A/en
Priority to GB9705955A priority patent/GB2308255B/en
Publication of WO1996009727A1 publication Critical patent/WO1996009727A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0007—Construction
    • H04Q2011/0026—Construction using free space propagation (e.g. lenses, mirrors)
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q11/00—Selecting arrangements for multiplex systems
    • H04Q11/0001—Selecting arrangements for multiplex systems using optical switching
    • H04Q11/0005—Switch and router aspects
    • H04Q2011/0052—Interconnection of switches
    • H04Q2011/0056—Clos

Definitions

  • the present invention relates to a switch for connecting one or more data inputs to one or more outputs, in which the interconnections are made optically, through the use of light beams directed between the inputs and outputs.
  • the crossbar switch comprises an array 2 of crosspoints CP.. .. CP.., which represent on/off switches; with four inputs INPUT .. INPUT on input lines 4, and four outputs OUTPUT- .. OUTPUT on output lines 6.
  • N for a crossbar switch having N inputs and N outputs the number of crosspoints required to connect any one of the N inputs to any one of the N outputs is N 2, ie here there are sixteen crosspoints.
  • each of the input lines 4 is connected to four crosspoints and the crossbar switch therefore has a fan-out of four.
  • a crossbar switch having N inputs and N outputs has a fan-out of N and a fan-in of N.
  • the crossbar switch is a single-stage type, since there is only a single interconnection in ' the path between any particular input and output.
  • the crossbar switch is also known as a non-blocking crossbar switch, since provided a given input or output is not already in use a connection can always be made between the given input and any output.
  • INPUT is connected to OUTPUT by crosspoint CP- _
  • INPUT is connected to OUTPUT- by crosspoint CP_-
  • INPUT is connected to OUTPUT- by crosspoint CP.-
  • INPUT is connected to OUTPUT by crosspoint CP .
  • the shutter matrix 12 comprises N 2 (sixteen) shutters which constitute the crosspoints arranged as an N by N (four by four) array.
  • the shutter matrix 12 is a spatial light modulator, as will be described further hereinbelow.
  • a first cylindrical lens (not shown) is positioned between the linear array 8 and the shutter matrix 12, and a second such lens is positioned between shutter matrix 12 and linear array 10.
  • each input source in the linear vertical array projects light onto each of the shutters in the corresponding row of the shutter matrix.
  • each output detector in the linear horizontal array may receive light through each of the shutters in the corresponding column of the shutter matrix.
  • the shutter matrix 12 may be a non-emitting device such as a pixellated spatial light modulator (SLM) .
  • SLM pixellated spatial light modulator
  • Such switches provide a form of interconnection in which not only is free-space optics used to greatly increase the connectivity between interfaces to avoid the bandwidth and pin-out limitations associated with electronics type switches, but in which the actual switching operations occur in free-space optics.
  • the optical interconnections are both "massively parallel” and reconfigurable.
  • Such reconfigurable optical interconnections can be advantageously utilised in a variety, of applications, as diverse as telecommunications switches, processor interconnections and parallel computing, opto-electronic implementations of neural networks, image processing (e.g. motion compensation) and arithmetic processing (e.g. matrix manipulation) .
  • Figure 3 shows a source of light 20 which is converted into a discrete array of light sources 24 by means of a Fourier grating or hologram 22.
  • a first lens (not shown) is positioned between the source of light 20 and the grating 22, and a second lens (not shown) is positioned between the grating 22 and the discrete array 24.
  • the input itself comprises an array
  • the array itself is replicated, as illustrated in Figure 4.
  • An FPAG is positioned between the array 30 of light sources and the shutter matrix 32, and a set of fan-in optics positioned between the shutter matrix 32 and the array 34 of output detectors.
  • both the fan-out and the fan-in of the optical crossbar switch are improved, relaxing the numerical aperture requirements of the optics.
  • each input is an input "image” made up of a number of data bits or pixels representing a data block, and this image is then connected en bloc to an output capable of resolving the image.
  • image is still passed through only a single shutter in the shutter matrix, but it is found that because the image generally has an increased extent compared to a discrete point input the size of that shutter must be increased to accommodate the image, and this also increases the overall physical size of the shutter matrix.
  • This arrangement represents a radical departure from the prior art arrangements described above, in that instead of providing a routing arrangement between the input and output planes, the routing is effectively performed before presentation of the input data by means of providing illuminating beams at a plurality of angles.
  • the input data is used to modify the illuminating beams and is thus projected to the output or outputs to which each input is to be optically connected.
  • the switching of data blocks can be readily effected.
  • the routing pattern between inputs and outputs is controlled by the illumination pattern, and the data image is not required to illuminate any shutter type device, the size problems associated with shutter matrices used for handling images are avoided. So too are the image degradition problems associated with the FPAG arrangement described above.
  • Use of control of the angle of incidence of illumination of the displayed input data provides an extremely simple effective means of providing routing control, which can be readily utilised to provide N to N routing even for large N.
  • the illumination means comprise an optical assembly having a source or sources of illumination, means for generating a plurality of beams from said illumination source or sources directed onto respective input data elements at each possible angle of incidence, and shutter means disposed between said source or sources of illumination and said input device to interrupt selected beams, to thereby control the pattern of connections between inputs and outputs.
  • the shutter means which may be a shutter matrix device embodied as a spatial light modulator, is required to shutter the illumination beams for the input device, rather than shuttering the data-carrying beams themselves, as occurs with the prior art devices discussed above.
  • the illumination means further comprise an assembly of lenses which direct the beams through optical paths in which at a point in each path each beam is substantially focused, said shutter means associated with that beam being disposed in the region of this point. This facilitates accurate shuttering and allows for a more compact shutter device.
  • the means for generating the plurality of beams may comprise a fixed fan-out hologram, and the lens assembly may comprise a Fourier lens which focuses said beams, followed by a lens array directing said beams onto respective elements of the input device.
  • the means for generating the plurality of beams may comprise a fixed fan-out hologram array, having holograms associated with each element of the input device, and the lens assembly may comprise a first array of lenses which focuses said beams, followed by a second lens array, with each array having a lens associated with each element of the input device.
  • This arrangement is particularly advantageous in that each hologram of the array is required for fan-out to only N points, followed by an array of only N lenses.
  • the illumination means comprise a source of illumination, and a dynamic hologram array, which is generated by a computer and which produces from the illumination source a plurality of beams incident on the input device at selected positions and at selected angles of incidence.
  • the input device is located immediately adjacent the dynamic hologram array.
  • the illumination means comprise an array of light emitting devices, such as light emitting diodes, and a lens array to direct the emitted light onto the elements of the input device.
  • Each diode provides a beam directed onto one element of the input device at one particular angle of incidence.
  • the lens arrangement comprises a single long-focal length lens followed by a lens array in which there is provided a lens associated with each output detector.
  • Figure 1 is a schematic diagram of the architecture of a basic crossbar switch
  • Figure 2 is a schematic diagram illustrating how the basic crossbar switch of Figure 1 may be implemented in free-space optics
  • Figure 3 illustrates how a two-dimensional array of light points may be generated from a single input light point using a Fourier phase array generator
  • Figure 12 illustrates schematically the switching of data blocks
  • Figure 13 illustrates schematically an application of the optical crossbar switch of the present invention in a high-level packet switch architecture.
  • an input array 36 is provided at an input plane, at which input data from input data lines is presented or displayed optically as an array, for example on a spatial light modulator which receives the data as electronic signals and displays these optically.
  • the arrangement shows four input elements I ... I .
  • An output array 38 is an array of optical detector elements, 0....0. which detect incident optical beams and pass these to respective output lines as electronic (or possibly optical) signals, constituting the output of the switch.
  • the routing pattern of connections between the input and output elements is controlled by both spatial and angular control of the illumination incident on the elements within the input array, as now described.
  • the arrangement for illumination of the input array 36 comprises an array 40 of light sources S. 1...S4. and a device 42 for control of the illumination reaching the input array 36, such as a shutter matrix.
  • An optical arrangement between the source array 40 and the shutter matrix 42 (such as a Fourier plane array generator or FPAG) is utilied to replicate the light sources S. .. S over the shutter matrix 42.
  • An additional optical system is positioned between the shutter matrix 42 and the input array 36, such that each of the four shutters in the shutter matrix 42 onto which the light source S is projected will, when the respective shutter is open, illuminate the input element I..
  • the lens 60 forms two collimated beams 66 and 68 from the illumination sources 52 and 54, which cross and then diverge.
  • the lens 62 forms two collimated beams 70 and 72 which cross and then diverge away from each other.
  • the beams 66 and 68 coincide, whilst the beams 70 and 72 will coincide.
  • the plane where this coincidance occurs is utilised as the illumination plane 64, and it is in this illumination plane 64 where the two inputs of the input array (not shown) are located.
  • One input of the input array is arranged at the region 74 where the collimated beams 66 and 68 coincide and the other input of the input array is arranged at the point 76 on the illumination plane where the collimated beams 70 and 72 coincide.
  • N to N routing (ie where each input is connected to a single output only) one of the two illumination sources 52 and 54 associated with each lens is emitting at any one instant.
  • the input positioned at region 74 on the illumination plane will be projected in one of two directions according to which of the two illumination sources 52 and 54 is emitting.
  • the input positioned at point 76 on the illumination plane will be projected in one of two directions according to which of the two illumination sources 56 and 58 is emmitting.
  • the spatial separation of the four illumination sources 52..58 is transformed into an angular separation (or multiplexing) of the collimated beams 66..72.
  • the illumination sources 52 .. 58 are shown arranged in a linear array, in general (for larger N) these would be arranged in a 2-dimensional array, with a corresponding 2-dimensional array of lenses.
  • N inputs there are provided N lenses, and N 2 emitters.
  • the arrangement comprises a phase modulating device 80 on which which can be displayed a set of reconfigurable diftractive phase holograms, in this example two holograms 90 and 92, but in the general case of N inputs and outputs, a set of N holograms. These are pre-generated by a computer.
  • the generated and displayed holograms 90 and 92 are configured such that a blanket of incident illumination 78 either interrupts the illumination or creates beams diffracted away from the optic axis through some angle according to the angular multiplexing required.
  • the hologram 90 will be configured in one of two configurations such that the incident light may be interrupted, or deflected in one of two directions either as a collimated beam 82 or as a collimated beam 84.
  • the hologram 92 will also be configured in one of two configurations such that incident light may be interrupted or may be deflected in one of either two directions as a collimated beam 86 or as a collimated beam 88.
  • the illumination scheme of Figure 7 has-its illumination plane (i.e. the plane in which the inputs are placed) directly behind the array 80, it is possible to combine, onto a single modulating device, the phase modulation property of the holograms of the array (which control the directions of the collimated beams) with an amplitude modulating function representing the input data.
  • Figure 8 illustrates a third arrangement for generating the angularly controllable illumination, comprising a fixed fan-out hologram 94 which is illuminated by a
  • the fixed fan-out hologram may be carried on a conventional etched glass plate.
  • the selection plane passes through the focal point of Fourier lens 96.
  • the four points 98..104 are directly equivalent to the four illumination sources 52..58 described hereinabove with reference to Figure 6, such that a similar lens array 60,62 can be utilised to produce the collimated beams which coincide at the illumination plane 64.
  • the beams are permanently directed at the points 98-104. It is here therefore necessary to place a device in the selection plane 106 which can 'block' the illumination at each point 98..104, such as a shutter matrix, embodied as a spatial light modulating device.
  • a shutter matrix has a shutter for each point 98..104.
  • the shutters of the shutter matrix are electronically controlled through means well known in the art to achieve the desired illumination of the input array to thereby achieve the desired routing pattern between input and -output.
  • each hologram 114 and 116 fans out to only two points (in the general case each of N holograms fans out to N points) , followed by the array of two (in the general case N) lenses to complete the fan-out focused to four points (in the general case N 2 points) in the selection plane.
  • the apparatus of Figure 8 has a single hologram, regardless of the number of inputs, required to fan out as four (in the general case N 2) points; as N increases, the high degree of fan-out required can create problems of beam uniformity and aberration problems.
  • the shutter matrix 146 is an amplitude type pixellated spatial light modulator. This may use opto-electronic integrated circuits fabricated in silicon VLSI technology and integrated with Ferro-electric liquid crystals, as described in the article entitled "Active backplane spatial light modulators using smectic liquid crystals" of W.A. Crossland et al in Proc SPIE, Liquid Crystal Materials, Devices and Applications 1665:114-127, 1992. Such a switch is particularly well suited to a communication switch application in terms of speed, reliability and ease of interfacing to peripheral electronics.
  • the shutter matrix has four shutters 138..144 onto which the beams are focused by the lenses 110 and 112 as discussed hereinabove.
  • the input data for the switch is displayed as an input array on a further pixellated SLM device positioned at the illumination plane 64. In the illustrated embodiment there are two inputs, A and B.
  • a collimated beam which provides the blanket illumination 78 incident on this fixed fan-out hologram array 108.
  • an illumination is provided by means of a laser 120 which generates a narrow beam of light into a spatial filter 124.
  • the spatial filter disperses this narrow beam into a broad diverging beam of light 128 which is collimated by lens 126 into a parallel beam.
  • the fixed fan-out hologram array has two holograms 114 and 116 (N in the general case) .
  • the hologram 116 generates collimated beams 134,1"36 focused into convergent beams which form points at 142,144 in the plane 106. If the shutter of the shutter matrix 146 associated with the point 142 is open, the light diverges from the point 142, and is then focused by the lens 62 into a collimated beam 162. The collimated beam 162 illuminates the image B on the data input array in the illumination plane. If the shutter of the shutter matrix 146 associated with the light point 144 is open, the light diverges from the point 144 and is then focused by the lens 62 into a collimated beam 160. The collimated beam 160 illuminates the image B on the input array at the illumination plane at a different angle to the beam 162.
  • the output of the switch comprises a further opto-electronic device 163 comprising a plurality of optical detectors arranged at an output plane.
  • This may be a fibre array, light-sensitive photodiode array or charge-coupled device array interfacing back to the electronics.
  • two detectors or detector elements 165,167 are required (N in the general case) .
  • an output lens arrangement is provided comprising a lens 150 and lens array having two (N in the general case) lenses 152,154.
  • the lens 150 is positioned beyond the illumination plane 64 such that the collimated beams 158 and 160 are focused at a point 164 in the focal plane of the lens 150, which is also in the focal plane of the lens 152.
  • the lens 152 produces collimated beams 168,172 which are detected by the detector element 165.
  • the collimated beams 156 and 162 are focused through a point 166 in the focal planes of the lenses 15O and 154 into collimated beams 170 and 174 to be detected by the second detector element 167.
  • the routing pattern between inputs A,B at the input array 148 and outputs 165 and 167 is then controlled by the selective opening of shutters at the shutter matrix 146.
  • the input A can be projected onto either one of the two output detectors 165,167 by opening one of the two shutters associated with the points 138 and 140
  • the image B can be projected onto either one of the two output detectors by selecting one of the two shutters associated with the points 142 and 144.
  • the angular multiplexing of the optical crossbar switch will occur in two dimensions rather than the one dimension illustrated with reference to Figures 6 to 10.
  • the illumination plane and the output plane will be filled with two dimensional arrays of data or images.
  • the image A represented in the collimated beams 168 and 170 is inverted with respect to the input image in the illumination plane 64.
  • the image B represented in the collimated beams 172 and 174 is inverted which respect to its input image in the illumination plane 64.
  • Figure 10 utilises an angular illumination scheme such as that described with reference to Figure 9, it will be appreciated that any of the angular illumination schemes of Figures 6 to 8 could be utilised.
  • the lens 150 generates two image points 164,166 (N image points in the general case) in its focal plane.
  • the generation of N image points leads to some degree of spatial registration error between the final collimated outputs, 168,172 associated with lens 152 and outputs 170,174 associated with lens 154.
  • This spatial registration error may cause difficulties for detection of the collimated beam, detector 165 being required to detect both beams 168 and 172.
  • This effect is greatly exaggerated in Figure 10, and in the usual case where f_ (the focal length of lens 150) is very much greater than f- (the focal length of lenses 152,154) the effect is small so that any offset is tolerated by the detectors.
  • Figure 11 illustrates a modification of the arrangement of Figure 10 which uses additional optics 180 termed registration compensation optics, positioned between the illumination or input plane 64 and the lens 150 (or alternatively between plane 64 and lenses 60,62) . These can take the form of N lenses or phase gratings to cancel the input spatial separation. As can be seen from
  • the introduction of the optics 180 causes there to be four (in the general case N 2) image points in the focal plane of the lens 150.
  • the two collimated beams 168 and 172 now coincide exactly at the output plane 182.
  • serial input data in the time domain may be converted to parallel data in the space domain such that the optical switch can operate at a speed much lower than that at which the serial data is inputted.
  • Such a technique would require some form of buffering in the input plane.
  • data entering the optical space switch in a serial form may be buffered and presented to the opto-electronic input plane as two-dimensional blocks of data. This principle is illustrated with respect to Figure 12.
  • the switching entity is therefore whole blocks of data rather than individual data bits. Because the data is switched as a parallel transfer of blocks, the switch is required to operate at a speed very much lower than that at which the data is received on a particular line i.e. the line bit rate.
  • the packet in contention must be delayed until the next routing transfer period.
  • Such a delay can be achieved by electronic buffering at the input, optical buffering at the input or switch feedback.
  • electronic buffering the packet in contention is delayed by the input electronics and not displayed on the optical crossbar switch input plane until the contention has been cleared.
  • optical buffering the packet in contention is displayed and held on the input plane but is not routed to the output plane until the contention has been cleared.
  • switch feedback the packet in contention is optically routed to a reserved external output slot which simply feeds the packet back to the switch input to be dealt with in the next routing transfer as a normal input packet.
  • FIG. 13 a high level block diagram of a packet switch architecture employing the optical space switch of the present inveniton is shown by way of example.
  • Serial input data is transmitted on each of the N input optical fibres I ..I which form inputs to an input buffering and formatting block 208.
  • the input buffering and formatting block 208 performs the conversion to parallel data blocks to be displayed on an input plane 202 of an optical space switch 200, as described hereinabove with reference to Figures 10, 11 and 12.
  • the data blocks are transmitted from the input buffering and formatting block 208 to the input plane via connections 218.
  • the input buffering and formatting block 208 also transmits the control and address information associated with the incoming data to a packet header processing block 212 via connections 234.
  • the data blocks on the optical input plane 202 are spatially arranged in blocks as described with reference to Figure 12 and illuminated by means of a routing and illumination block 204.
  • An output buffering and decoding block 210 receives the data signals on the output plane 206 via connections 224 together with output signals from the packet header replacement block 216 via the connections 232. The output buffering and decoding block 210 then reconstructs the data blocks into serial packet form with appropriate control and address headers, and transmits serial data packets on output optical fibres 0...0...
  • the header associated with a data packet may comprise not only an address identifying which one of the N optical fibres 0-..0 tent the packet is to be routed to, but also addresses of other locations to which the packet is to be routed as it progresses from its source to its destination, as well as error checking bits, framing bits and control bits such as packet identification bits.
  • the communications application of the switch of the present invention described provides for high capacity time-space-time switching with the input and output buffering performed electronically and having additional interfaces for routing control, the actual routing being performed in the spatial domain.
  • the high capacity of such a switch is provided for by the angular encryption of positionally encrypted input data.
  • This dual multiplexing technique can be used in any parallel processing application where a high degree of interconnection is required.
  • a very high degree of parallelism can be provided, allowing a degree of miniaturisation which is impossible to achieve in an electronic system.
  • this parallelism can be utilised to route parallel blocks of data which are received serially, thereby allowing the switch to operate internally at a reduced data rate and allowing more time for reconfiguration of the switch without a reduction in the external serial bit rates.
  • the architecture of the optical crossbar swtich proposed by the present invention whereby the routing pattern is optically encrypted before performing the presentation of the input data in the input plane, requires reduced optical resolution requirements as compared to previous architectures having a high fan-out and fan-in, in particular where data blocks or images are being switched as individual units.
  • the arrangement also ensures that all optical components within the architecture scale to the number of inputs N rather than the number of interconnectors N 2.
  • the size and scalability of the switch is not limited by the optical power requirements of the optical transmission fibres.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)

Abstract

L'invention porte sur un commutateur permettant de connecter une ou plusieurs entrées de données à une ou plusieurs sorties de données. On réalise les interconnexions par voie optique en utilisant des faisceaux lumineux dirigés entre les entrées et les sorties. Un dispositif d'entrée est éclairé par un tableau émetteur de manière que la sortie sélectionnée soit fonction de l'angle d'incidence du faisceau lumineux.
PCT/GB1995/002245 1994-09-23 1995-09-21 Commutateur optique a barres croisees Ceased WO1996009727A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU35278/95A AU3527895A (en) 1994-09-23 1995-09-21 Optical crossbar switch
GB9705955A GB2308255B (en) 1994-09-23 1995-09-21 Optical crossbar switch

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9419278A GB9419278D0 (en) 1994-09-23 1994-09-23 Optical crossbar switch
GB9419278.8 1994-09-23

Publications (1)

Publication Number Publication Date
WO1996009727A1 true WO1996009727A1 (fr) 1996-03-28

Family

ID=10761841

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1995/002245 Ceased WO1996009727A1 (fr) 1994-09-23 1995-09-21 Commutateur optique a barres croisees

Country Status (3)

Country Link
AU (1) AU3527895A (fr)
GB (1) GB9419278D0 (fr)
WO (1) WO1996009727A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6233736B1 (en) 1996-02-08 2001-05-15 Media Online Services, Inc. Media online service access system and method
US8937759B2 (en) 2001-09-03 2015-01-20 Thomas Swan & Co. Ltd. Optical processing
US10257594B2 (en) 2012-08-15 2019-04-09 Thomas Swan And Co., Ltd. Optical device and methods

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2171241A1 (fr) * 1972-02-09 1973-09-21 Philips Nv
WO1980001028A1 (fr) * 1978-11-08 1980-05-15 Rozenwaig Boris Dispositif de commutation de signaux par des moyens optiques et autocommutateurs comportant ce dispositif
EP0423434A1 (fr) * 1989-10-18 1991-04-24 International Business Machines Corporation Ordinateur à multiprocesseur avec un commutateur de données optique
GB2269296A (en) * 1992-08-01 1994-02-02 Northern Telecom Ltd Telecommunications switch architecture

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2171241A1 (fr) * 1972-02-09 1973-09-21 Philips Nv
WO1980001028A1 (fr) * 1978-11-08 1980-05-15 Rozenwaig Boris Dispositif de commutation de signaux par des moyens optiques et autocommutateurs comportant ce dispositif
EP0423434A1 (fr) * 1989-10-18 1991-04-24 International Business Machines Corporation Ordinateur à multiprocesseur avec un commutateur de données optique
GB2269296A (en) * 1992-08-01 1994-02-02 Northern Telecom Ltd Telecommunications switch architecture

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6233736B1 (en) 1996-02-08 2001-05-15 Media Online Services, Inc. Media online service access system and method
US8937759B2 (en) 2001-09-03 2015-01-20 Thomas Swan & Co. Ltd. Optical processing
US9529325B2 (en) 2001-09-03 2016-12-27 Thomas Swan & Co. Ltd Optical processing
US10180616B2 (en) 2001-09-03 2019-01-15 Thomas Swan & Co. Ltd. Optical processing
US10642126B2 (en) 2001-09-03 2020-05-05 Thomas Swan & Co. Ltd. Optical processing
US11073739B2 (en) 2001-09-03 2021-07-27 Thomas Swan & Co. Ltd. Optical processing
US10257594B2 (en) 2012-08-15 2019-04-09 Thomas Swan And Co., Ltd. Optical device and methods

Also Published As

Publication number Publication date
AU3527895A (en) 1996-04-09
GB9419278D0 (en) 1994-11-09

Similar Documents

Publication Publication Date Title
US5953143A (en) Multidimensional switching networks
US6657770B2 (en) Programmable optical multiplexer/demultiplexer
JPH03223728A (ja) 光相互接続ネットワーク
EP0397372A1 (fr) Topologie de réseau pour blocage réduit et un système photonique mettant en oeuvre celle-ci
US5798580A (en) Contention free global interconnection
JPH06214278A (ja) 光インターコネクションネットワーク
JPH08146471A (ja) 光スイッチおよび光情報伝送装置
US7127136B2 (en) Optical crossbar switch
EP0397369B1 (fr) Dispositif optique pour combiner des réseaux lumineux de longueurs d'ondes différentes
US4917456A (en) Optical crossover network
EP0397368A1 (fr) Procédé de commande d'un réseau de commutation à division spatiale
US5887090A (en) Optical network
WO2020024840A1 (fr) Appareil et système de commutation en longueur d'onde
WO1996009727A1 (fr) Commutateur optique a barres croisees
US7174065B2 (en) Optical switching fabric with an optical to electrical converter in the output plane
US6538818B2 (en) Method and device for wavelength switching, wavelength division multiplexing, and time division multiplexing
US20240369774A1 (en) Extendable optical circuit switch architecture
US7031611B2 (en) Optical routers using angular position amplification modules
US20020061161A1 (en) Optical switch
JP2735877B2 (ja) 多端子光スイッチ
Yamaguchi et al. Recent free-space photonic switches
KR100245393B1 (ko) 편광 변조 표면방출 레이저를 이용한 광스위칭 장치
RU2072540C1 (ru) Многокаскадный оптоэлектронный коммутатор изображений
JP3197611B2 (ja) 多端子光スイッチ
US20020085795A1 (en) Optical device

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AM AT AU BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IS JP KE KG KP KR KZ LK LR LT LU LV MD MG MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TT UA UG US UZ VN

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE MW SD SZ UG AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA