('12) Ulllted States Patent
`(10) Patent N0.:
`US 6,928,244 Bl
`
`Goldstein et al.
`(45) Date of Patent:
`Aug. 9, 2005
`
`
`U8006928244B1
`
`(54)
`
`(75)
`
`SYSTElVl AND NIETHOD 0F WAVELENGTH
`ADD/DROP MULTIPLEXING HAVING
`CLIENT CONFIGURABILITY
`
`Inventors: Evan L. Goldstein, Princeton, NJ (US);
`Lih-Yuan Lin, Lime Silver, NJ (us);
`Chuan Pu, Middletown, NJ (US);
`Robert William Tkach, Little Silver,
`NJ (US)
`
`(73) Assignee: AT&T Corp., New York, NY (US)
`
`(_ * ,) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(1)) by 573 days.
`
`(21) Appl. No.: 09/722,955
`(22) Filed:
`Nov. 27’ 2000
`
`(51)
`
`(60)
`
`Related US. Application Data
`Provisional application No. 60/172,732, filed on Dec. 20,
`33991213386315101131 application N°~ 609049452: filed on
`y
`’_
`'
`Int. CL/ ~~~~~~~~~~~~~~~~~~~~~~~~~~ H04J 14/00; H04] 14/02;
`GOZB 6/26; GOZB 6/42
`(52) U-S- CL -------------------------- 398/45; 398/51; 398/54;
`398/83; 385/17; 385/18
`(58) Field of Search .............................. 398/45, 51, 54,
`398/83, 82; 385/17, 18
`
`9/1997 Dugnay ...................... 385/17
`5,671,304 A *
`5,841,917 A * 11/1998 Jungcrman ct al.
`........... 385/17
`6.144,781 A * 11/2000 Goldslein et al.
`. 385/18
`6,335,992 B1 *
`1/2002 Bala et al.
`. 385/17
`5,356,679 I“ *
`3/2002 KaPany --------
`385/18
`6,445,841 B1 *
`9/2002 Gloeckner et al.
`.
`. 385/17
`. 385/18
`6,480,645 B1 * 11/2002 Peale et al.
`
`2/2003 Liu ............................. 398/49
`6,519,060 B1 *
`
`
`
`..
`
`* cited by examiner
`
`Primary Examiner—Ml R. Sedighian
`
`ABSTRACT
`(37)
`An optical carrier drop/add transmission system and method
`for adding a signal to multiplexed input optical signals
`convcycd by an optical mnltiplcx input linc. Thc multi-
`plexed input optical signals are dernultiplexed to provide
`isolated input optical signals to an optical switch matrix
`comprising switches in an array of lines and columns, the
`isolated input optical signals being inputted in a direction
`parallel to a line of switches in the optical switch matrix. The
`added optical signal is input in a direction parallel to a
`column in the optical switch matrix. An output
`line is
`selected and the switch that is on the column on which the
`added optical signal is inputted and on the selected output
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`fine is SWiIChed‘
`
`5,581,643 A * 12/1996 Wu ............................. 385/17
`
`10 Claims, 9 Drawing Sheets
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`ADD PORT
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`Im| |Ifl|
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`I
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`I
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`I
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`I
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`
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` 710
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`mTTT
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`DROP PORT
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`750
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`Petitioner Ciena Corp. et al.
`
`Exhibit 1033-1
`
`

`

`US. Patent
`
`Aug. 9,2005
`
`Sheet 1 0f 9
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`US 6,928,244 B1
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`ADD PORT
`
` 120
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`112
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`Fig. 1
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`110
`
`Petitioner Ciena Corp. et al.
`Exhibit 1033-2
`
`W)
`
`

`

`US. Patent
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`Aug. 9,2005
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`Sheet 2 0f 9
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`US 6,928,244 B1
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`ADD PORT
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`IuII IL.
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`282
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`260
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`270
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`
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`I
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`251A
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`I
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`I
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`I
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`251B
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`251C
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`251D
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`I
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`
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`DROP PORT
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`200
`
`Fig. 2
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`250
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`Petitioner Ciena Corp. et al.
`Exhibit 1033-3
`
`

`

`US. Patent
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`Aug. 9,2005
`
`Sheet 3 0f 9
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`US 6,928,244 B1
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`ADD PORT
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`
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`260
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`I
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`251B
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`250
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`l
`I
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`II
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`I
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`I
`I
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`III
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`I
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`251A
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`251B
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`251C
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`251D
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`DROP PORT
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`Fig. 3
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`Petitioner Ciena Corp. et al.
`Exhibit 1033-4
`
`

`

`US. Patent
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`Aug. 9,2005
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`Sheet 4 0f 9
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`US 6,928,244 B1
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` ADD PORT
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`II 24113 I241C 241D I 241E
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`I
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`251A
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`2513
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`251C
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`I
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`II
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`DROPPORT
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`250
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`Fig. 4
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`Petitioner Ciena Corp. et al.
`Exhibit 1033-5
`
`

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`US. Patent
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`Aug. 9,2005
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`Sheet 5 0f 9
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`US 6,928,244 B1
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`410
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`DROPPED SIGNAL
`PROCESSOR
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`
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`MATRIX
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`ADDED SIGNAL
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`CONTROLLER I PROCESSOR
`
`
`- —
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` SIGNAL MANAGER
`
`I ADDPORT
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`
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`420
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`DROP PORT
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`108
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`114
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`170
`
`Fig. 5
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`400
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`Petitioner Ciena Corp. et al.
`Exhibit 1033-6
`
`

`

`US. Patent
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`US. Patent
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`Aug. 9,2005
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`Sheet 7 0f 9
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`US 6,928,244 B1
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`Petitioner Ciena Corp. et al.
`Exhibit 1033-8
`
`
`
`

`

`US. Patent
`
`Aug. 9,2005
`
`Sheet 8 0f 9
`
`US 6,928,244 B1
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`840
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`860
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`I
`
`I
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`I
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` I
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`DROP PORT
`
`Fig. 8
`
`Petitioner Ciena Corp. et al.
`Exhibit 1033-9
`
`

`

`US. Patent
`
`Aug. 9,2005
`
`Sheet 9 0f 9
`
`US 6,928,244 B1
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`840
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`860
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` DROP PORT
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`I
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`I
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`
`851A
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`851C
`
`851D
`
`Fig. 9
`
`Petitioner Ciena Corp. et al.
`Exhibit 1033-10
`
`

`

`US 6,928,244 B1
`
`1
`SYSTEM AND METHOD OF WAVELENGTH
`ADD/DROP MULTIPLEXING HAVING
`CLIENT CONFIGURABILITY
`
`This non-provisional application claims the benefits of
`US. Provisional Application No. 60/172,732 entitled
`“Wavelength add/drop Multiplexer With Client Config—
`urability" which was filed on Dec. 20, 1999 and is hereby
`incorporated by reference in its entirety. The applicants of
`the provisional application are Evan L. Goldstein, Lih-Yuan
`Lin and Robert W. Tkach.
`This non-provisional application also claims the benefits
`of US. Provisional Application No. 60/204452 entitled
`“Micro-machined Optical Add/Drop Multiplexer With Cli-
`ent Configurability” which was filed on May 16, 2000 and
`is hereby incorporated by reference in its entirety. The
`applicants of the provisional application are Chu an Pu, Evan
`L. Goldstein, Lih-Yuan Lin and Robert W. Tkach.
`BACKGROUND OF THE INVENTION
`
`1. Field of Invention
`
`This invention relates to optical communication. More
`particularly, this invention relates to systems and methods
`using optical switches for adding and dropping channels
`from an optical transmission medium.
`2. Description of Related Art
`In current optical communication systems, multiple chan—
`nels are multiplexed onto a single optical
`transmission
`medium using multiplexing techniques, such as wavelength-
`division-multiplexing (WDM). WDM can combine a plu-
`rality of communication channels, in the form of discrete
`wavelengths, onto a single optical fiber. As multiplexing
`techniques improve, an increasing number of channels are
`being transmitted on a single optical fiber or group of optical
`fibers. As the number of channels increase, so too does the
`need for an ability to add and/or drop a portion of the
`channels to and/or from the transmission medium.
`Current communication systems can use an opto-
`electronic regeneration technique to add and drop channels
`from a transmission system. With such a technique, in order
`to receive or transmit data on the optical network using
`WDM, a node of the network can include at least one optical
`sensor that receives the optical signal at one or more
`wavelengths. The optical sensor can include an optical-
`electrical converter that can convert the optical signal to
`electrical signals corresponding to the received optical sig-
`nals. Adding and/or dropping of the signals can then be
`performed electronically by processing the electrical signals
`in the electrical domain. The resulting electrical signal can
`then be modulated onto the network using an electro-optical
`converter. Such Optical-Electrical-Optical (0E0) conver-
`sion can be very complex, costly and time consuming.
`Additionally, optical wavelength add/drop multiplexers
`(OADM) can be used in WDM transmission systems.
`Currently,
`it has been well recognized that OADMs are
`needed to avoid the complex and costly OEO conversions.
`However, currently available OADMs are generally fixed. In
`other words, a given incoming channel (wavelength) is only
`associated with a fixed add/drop port. Such a device lacks
`"client-configurability” and therefore severely limits the
`selection of which channels to add/drop for a client.
`Therefore, there exists a need for a device to add and drop
`channels from a transmission medium that can be readily
`configured according to the needs of a client.
`SUMMARY OF THE INVENTION
`
`The invention provides an optical switch matrix device
`and methods that selectively add and drop channels from an
`
`5
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`1D
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`15
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`35
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`4O
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`45
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`50
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`55
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`65
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`2
`optical communication medium. The optical switch matrix
`can receive an input signal from an optical medium, such as
`an optical fiber cable. The input signal can include numerous
`input channels, for example a plurality of channels each
`having a different wavelength. The optical switch matrix can
`also receive an add signal which can include numerous add
`channels for different clients; each add channel can replace
`an input channel of the input signal that is dropped.
`Depending on the configuration of the optical switch
`matrix, any channels of the input optical signal can be
`dropped from the communication medium to any of the
`clients. The dropped channels can be received and processed
`by a receiver. Further, any channels from the add signal can
`be added to he communication medium. The added chan-
`nels along with the remaining channels of the input signal
`can then be outputted and transmitted on the communication
`medium. Di erent from fixed optical wavelength add/drop
`multiplexers (OADMs) described in the related art,
`the
`invented optical switch matrix can be configured to allow
`each client 0 access any of the input channels, therefore
`offering client-configurability to the network.
`The optical switch matrix can be a device that operates on
`the optical channels in the optical domain. For example, the
`optical switch matrix can be a device, such as a micro
`electrical mechanical system (MEMS), having an array of
`micromirrors that are rotatably mounted on a substrate. The
`micromirrors may be selectively positioned to interact with
`passing light, so as to redirect light beams between ports of
`the optical switch matrix. Accordingly, the optical switch
`matrix can add/drop channels to/from an optical communi—
`cation medium.
`
`
`
`
`the
`Alternatively, or in conjunction with the MEMS,
`optical switch matrix can be a device such as a matrix of
`switches utilizing bubble technology. As an optical channel
`passes through the optical switch matrix, bubble switches
`can be selectively activated causing the channel
`to be
`redirected between ports of the optical switch matrix.
`Accordingly, the optical switch matrix can add/drop chan-
`nels tO/from an optical communication medium.
`These and other features and advantages of this invention
`are described in or are apparent from the following detailed
`description of the system and method according to exem-
`plary embodiments of this invention.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`invention will be readily
`The benefits of the present
`appreciated and understood from consideration of the fol—
`lowing detailed description of exemplary embodiments of
`this invention, when taken together with the accompanying
`drawings, in which:
`FIG. 1 is an exemplary block diagram of a wavelength
`add—drop device in accordance with the present invention;
`FIG. 2 is an exemplary block diagram of a wavelength
`add-drop device using MEMS technology in a unidirectional
`network in accordance with the present invention;
`FIGS. 3 and 4 are exemplary block diagrams of the
`wavelength add-drop device of FIG. 2 in two different
`functioning configurations;
`FIG. 5 is an exemplary functional block diagram of a
`wavelength add-drop device according to an embodiment of
`the present invention;
`FIGS. 6 and 7 are exemplary functional block diagrams of
`a wavelength add—drop device using MEMS technology in a
`bi-directional network in accordance with the present inven-
`tion; and
`FIGS. 8 and 9 are exemplary functional block diagrams of
`a wavelength add-drop device using MEMS technology in a
`bi—directional network in accordance with the present inven—
`tion.
`
`Petitioner Ciena Corp. et al.
`
`Exhibit 1033-11
`
`

`

`US 6,928,244 B1
`
`15
`
`4
`3
`The optical switch matrix 102 is a device that is capable
`DETAILED DESCRIPTION OF PREFERRED
`of redirecting optical signals passing through the optical
`EMBODIMENTS
`switch matrix 102. In this manner, a portion of the input
`FIG. 1 shows an optical switch matrix system 100 for
`channels 104a7104f can pass through the optical switch
`selectively adding and dropping channels from a transmis-
`matrix 102 to the output channels 106a—106f without any
`sion medium 120. The system 100 includes an optical switch
`substantial interference. In other words, these channels are
`matrix 102 having four ports: input port 104, output port
`permitted to pass nearly unabated through the optical switch
`106, add port 108 and drop port 110. The input port 104 is
`matrix 102 and continue to travel on the transmission
`optically coupled to a demultiplexer 112 for receiving input
`medium 120.
`channels 104a—104f from the transmission medium 120. The
`Alternatively, a portion of the input channels can be
`output port 106 is optically coupled to a multiplexer 114 for
`1U selectively redirected to a drop channel 11011—1108 of the
`transmitting optical channels 106a—106f onto the transmis-
`drop port 110 as the inputted channels 104a—104f pass
`sion medium 120. The add port 108 is optically coupled with
`through the optical switch matrix 102. In a similar manner,
`the optical switch matrix 102 for inputting added channels
`added channels 108a—108e can be selectively redirected to
`1080—1088 that are connected to different clients. The drop
`output channels 10611—106)” of the output port 106 for which
`port 110 is optically coupled with the optical switch matrix
`the corresponding input Channel has been dropped as the
`102 for transmitting drop channels ”Oil—“08, possibly for
`added channels pass through the optical switch matrix 102.
`further processing.
`According to this technique, input channels can be removed/
`Both the multiplexer 114 and the demultiplexer 112 are
`dropped and new channels can be added to the transmission
`optically coupled With the transmission medium 120, The
`medium 120-
`transmission medium 120 can include any structure that
`The optical switch matrix 102 can include an array of
`allows for
`the transmission of optical communication 20
`switches that can be in either an active or inactive state. In
`signals, such as an optical fiber. The optical communication
`an active state, the switch is able to redirect a light beam or
`signals can further include a plurality of channels that are
`channel passing in close proximity to the switch. In an
`simultaneously transmitted along the communication
`inactive state, the switch allows a light beam or channel to
`medium 120. For example, numerous channels having dis-
`crete wavelengths can be combined onto a single optical 25 pass without incident.
`the optical
`transmission medium using wavelength-division-
`As an example of operation, assume that
`multiplexing (WDM)~
`switch matrix 102 includes at least N><M matrix of switches
`is capable of
`The demultiplexer 112 is a device that
`that are initially in the inactive position. Further assume that
`optically dividing input signals received on the transmission
`the transmission medium 120 is transmitting an input signal
`medium 120 into a plurality of channels 104a7104f. Once an having 6 channels (AiF). In the initial state, the input signal
`the input channel is divided, the input channels 104a—104f T i can be received by the demultiplexer 112. The demultiplexer
`are transmitted to the optical switch matrix 102. As
`112 operates on the input signal to optically separate the
`
`
`described above, the channels can travel along the transmis-
`input signal into input channels 104a—104f. The input chan-
`
`
`sion medium 120 on di erent wavelengths.Additionally, the
`nels 104a7104f are then transmitted to the optical switch
`channels of the input signal can be combined on the trans-
`network 102.
`mission medium 120 according to any well known comrnu- 35
`In the initial state of the switch matrix 102, where all of
`HlCflthH technique, SUCh as TDMA, CDMA and the like.
`the optical switches are in the inactive state,
`the input
`Any technique that allows multiple channels to be transmit—
`channels 104a—104f are permitted to pass through the optical
`ted across the transmission medium 120 and separated by
`switch matrix to the output Channel 106a7106f without
`the demultiplexer 112 can be used without departing from
`being acted upon. Accordingly,
`the output channels
`the spirit and scepe of the present invention.
`40 106a—106f, corresponding to the input channels 10411—1041”
`The multiplexer 114 is a device that is capable of optically
`are transmitted to the multiplexer 114. The multiplexer 114
`combining the output channels 106a7106f received from the
`then optically operates on the output channels 106a7106f in
`optical switch matrix 102 into an output signal that is then
`order to combine the output channels 106LZ—106f into an
`transmitted on the transmission medium 120. As described
`output signal, and then transmit the output signal back onto
`above, the numerous output channels 106017106)” can travel 45 the transmission medium 120.
`along the transmission medium as an Olltpllt signal
`in
`During the course of operation, assume that it has now
`accordance with any known or later developed transmission
`become desirable to replace input channel 104C with an
`technique without departing from the spirit and scope of the
`added channel 108b. Accordingly, as the input channels
`present invention.
`104a—104f are transmitted through the optical switch matrix
`The add port 108 is a device that is capable of receiving 5U [02, one or more optical switches in the path of input
`channels 10801—1086 from different clients, and then trans—
`channel 104C could be switched to an active state whereby
`mitting the added channels 108a—108e to the optical switch
`the optical switch can redirect the light beam corresponding
`matrix 102. Data sources for the added channels I08a—I08e
`to input channel 104C to the specified drop port 110, such as
`can be generated by a plurality of light sources, such as
`dropped signal 110a. Furthermore,
`the add port 108 can
`tunable laser diodes, included in the add port 108. Each of 55 begin transmitting an added signal 108b into the optical
`the light sources can be adjusted to emit a channel having a
`switch matrix 102 and an optical switch in the path of added
`specific wavelength. The light sources of the add port 108
`channel 108b could be switched to an active state, and
`can further operate in accordance with instructions received
`thereby redirect the added channel 108b to output channel
`from a controller (not shown) in order to selectively output
`106C of the output port 106.
`an added channel Of a SPCCifiC wavelength. FOF example,
`Accordingly, the multiplexer would then receive the input
`added channels 108a—l086 can each be transmitted on 6“ channel 1040 on output channel 1060, the input channel
`different wavelengths hail, correSponding to the wave-
`l04b on the output channel 106b, the added channel 108b on
`lengths 0f the input channels.
`the output channel 106C, the input channel 104d on the
`The drop port 110 is a device that is capable of receiving
`output channel 106d, the input channel 104e on the output
`drop channels 110a—110e from the optical switch matrix
`channel 1066‘ and the input channel 104]” on the output
`102. Each of the channels can be of various wavelengths.
`65 channel l06f. The output channels l06a—l06fwould then be
`The drop port 110 can then output any of the drop channels
`combined by the multiplexer 114 and transmitted as an
`to a processor (not shown) [or further processing.
`output signal across the transmission medium 120. In this
`
`Petitioner Ciena Corp. et al.
`
`Exhibit 1033-12
`
`

`

`US 6,928,244 B1
`
`5
`manner, a channel of the input signal, 104C, has been
`replaced (dropped) during the addition of the added channel
`108b.
`
`6
`micromirrors 280 are in the inactive position. Next, assume
`that a determination has been made that a signal conveyed
`by the input line 260 is to be dropped. If so, it is determined
`on which line of the matrix the light ray that has the
`As is to be understood, the switches of the optical switch
`wavelength that carries the signal to be dropped is trans-
`matrix 220 can be changed at any time during operation to
`mitted. Next, the sensor 251A to 251M on which the signal
`add or drop channels to or from the transmission medium
`is to be received is determined. The micromirror 280 cor—
`120. In this manner, a user can easily configure the optical
`responding to that line and the column of that selected sensor
`switch matrix 102 to add or remove all or a portion of
`in the matrix is next positioned in the active position. Next,
`information from an optical network.
`a determination is made whether another signal conveyed by
`.
`.
`.
`As shown in FIG. 2, the optical switch matrix 102 can be in
`the input line 26.0 has to bedropped. The above operations
`a single microelectrical mechanical system (MEMS). This
`are repeated until no other Signal conveyed by the input line
`single MEMs design of the 0p11cal switch matrix can be
`260 has to be dropped.
`.
`.
`_
`.
`particularly useful for dropping and adding channels from an
`As mentioned above, Slhee the NXM matrix sw1tch 1h
`unidirectional ring network. The MEMs includes an array of
`micromirrors 280 that are rotatably mounted to a substrate 15 FIG. 2 is implemented in a unidirectional network, the add
`232. The micromirrors 230 are rotatable between a non—
`channels are always associated with the drop channels. That
`activated and activated position.
`In the non-activated
`is, the add Channel and drop Channel Oh the. same (:01th are
`position, the micromirrors 280 are substantially parallel and
`associated Wlth the same client. BY using the backside
`flush with the substrate 282.
`In the active position,
`the
`reflection of the activated micromirrors, and concurrently
`micromirrors 280 are rotated or flipped to be in a substan—
`tuning the lasers 0f
`the add channels to selected
`tially perpendicular position relative to the substrate 280. 20 wavelengths, Signals can be added 1ht0 traffic from the
`Furthermore, in the active position the micromirrors 280 ate
`selected add channels.
`positioned within the light path of channels passing through
`FIGS. 3 and 4 are exemplary functional block diagrams of
`the optical switch matrix.
`the wave ength add—drop device of FIG. 2 in two different
`This type of optical switch matrix is discussed in detail in
`functioning configurationscorresponding to a same set 0f
`Journal 0fMicroelectro—mechanical Systems, Vol. 5, No. 4, 25 dropped hght rays 11? a unidirectionalnetwork. 1h FIGS 3
`December 1996, entitled “Electrostatic Micro Torsion Mir—
`{thd 4, the dropped hght rays are the lights rays emitted by
`rors for an Optical Switch Matrix” by Hiroshi Toshiyoshi
`1hPhtP0r 5 211B and 211D, onthe second and fourth hheS
`and IIiroyuki Fujita, incorporated herein by reference in its
`9t sw1tch matrix 220- However, 1h the configuration Ohthheh
`entirety. The optical switch matrix is also discussed in
`m FIG 3: the hght ray transmittedon the secondline 15
`co-pending and commonly assigned patent application Ser. 30 dropped to the sensor 251D and the hght ray transmitted Oh
`No. 09/002,240 filed on Dec. 31, 1997, also incorporated
`the fourtt hhc {8 drhppcd t0 the .scnsor 25133111 the
`herein by reference in fig entirety.
`eonflgura ion outlined in FIG. 4, the light ray transmitted on
`As shown in FIG. 2, the wavelength add-drop device 200
`the secondline is dePEd to the Sensor 251C and the light
`includes an optical N ><M matrix switch 220 coupled to an
`ray transmitted on the fourth line 15 dropped to the sensor
`input demultiplexer 210, an output multiplexer 230, an add 35 251E
`port 240 and a drop port 250'
`Consecuently, in the configuration outlined in FIG. 3,.the
`The optical NxM matrix switch 220 can be a four-port
`added Signals are added by inputting light rays from the light
`matrix switch. In this embodiment, the optical NxM matrix
`sources 241B and .2411) I“ the configuration outlined ”1
`switch 220 is a NxM free space MEMS crossconnect that
`FIG‘ 4’ the added Signals are added by inputting hght rays
`comprises NxM micromirrors 280.
`In the exemplary 40 from the llght source 241C and 241E
`embodiment shown in FIGS. 2_4, N=6 and M=5. AS
`FIGS. 3 and 4 show that the wavelength add-drop device
`described above, each of the 30 micromirrors 280 shown in
`according to an exemplary embodiment 0f the invention can
`FIGS. 2—4 may take one of an active or inactive position.
`be configured to select which sensor 251A’251E receives
`The positions of the micromirrors 280 can be controlled
`the dropped signal and to select the hght source 241A—241E
`by a matrix controller (not shown in FIGS. 2—4). By ener- 45 that inputs the added Slghal'
`gjzing the switch that is on the 1”! row and the j”! column of
`The present invention describes a device that offers full
`the matrix switch, e.g., by flipping up the micromirror
`client-conflgurability, permitting any subset of the incoming
`switch on line i and column j, and concurrently tuning the
`wavelengths (1: 2:
`,
`~
`~ N) to he added or dropped at any
`light source on 241j to the wavelength used on the ith line,
`subset 0f the light sources 241A t0 241E or sensors 251A to
`one can thus add a wavelength from light source 24lj and/or 50 251E
`drop a wavelength at sensor 251j.
`An exemplary wavelength add—drop device 400 is out—
`Although the optical switch matrix 102 of FIG. 1 has been
`lined in FIG- 5, and includes a signal manager 410,
`the
`described in the exemplary embodiments of FIGS. 24 as
`optical NxM matrix switch 102, the input demultiplexer 112,
`being a MEMs type switch 220, it is to be understood that
`the OhtPht multiplexer 114, the add port 108: the drop port
`various other switches can be used without departing from 55 110, the mPUt hhe 160 and the OUtPht hhe 170-
`the spirit and scope of the present invention. For example,
`The signal manager 410 comprises a dropped signal
`the optical switch matrix 102 can be any type of optical
`processor 420, a matrix controller 430 and an added signal
`switch with or without a micromechanical element, such as
`processor 440. The dropped signal processor receives the
`optical switches based on total
`internal
`reflection of a
`signals output by the dropped channels 11061—1106 of the
`fluid-containing planar light wave circuit (PLC), otherwise
`drop port 110 and processes those signals, The matrix
`known as bubble technology. Such technology is more fully on controller 430 determines which micromirrors in the optical
`described in the article entitled “Compact Optical Cross-
`matrix switch 102 are to be turned to their active position
`Connect Switch based on Total Internal Reflection in a
`and commands the positions of the micromirrors. The added
`Fluid-Containing Planar Light Wave Circuit” by J. E.
`signal processor 440 provides the signals to be added
`Fouquet, in 2000 OFC Technical Digest, pp. 204 to pp. 206,
`through the add port 108 and the light sources 108A—108E.
`WhlL‘h is incorporated herein by reference in Its entirety.
`The signal manager 410,
`the dropped signal processor
`Referring again to FIG. 2, as an example of operation,
`420, the matrix controller 430 and the added signal proces—
`assume that
`in an initial state of operation, all of the
`sor 440 may be,
`in the exemplary embodiment of the
`
`
`
`65
`
`Petitioner Ciena Corp. et al.
`
`Exhibit 1033-13
`
`

`

`US 6,928,244 B1
`
`in
`
`7
`8
`adding optical signals may be carried out independently by
`invention shown in FIG. 5, a microprocessor that uses
`the optical matrix switches 820A and 820B which provide
`software to implement exemplary embodiments of the meth-
`full client-configurability since the add port and the drop
`ods and devices according to this invention.
`port associated with the same input channel or wavelength
`FIG. 6 shows a wavelength add-drop device 700 wherein
`are independent of each other due to the optical MxM matrix
`the optical switch matrix 102 includes two optical NxM
`8203.
`matrix switches 720A and 720B. This configuration of the
`FIG. 9 shows an example of operation of the embodiment
`optical switch matrix 102 having two MEMs can be par-
`described in FIG. 8. In this example, assume that it is desired
`ticularly useful for adding and dropping channels from a
`to replace a channel corresponding to input channel 811A
`bi-directional ring network and/or a linear network. The
`with a new channel, corresponding to the added channel
`» '
`.
`'
`'
`'
`-
`'
`,
`optical N><M matrix switch 720A is coupled to an input
`:41DitAsldeSttttétt1tgabohe’ the inptutdsrgnal ts. [Wines by ttic
`demultiplexer 710, a drop port 750 and the optical N><M
`811ml: 81t1t1tFXt1t1ts th . ant Sept“?8611Atttot inpuncdanne S
`matrix switch 720B. The optical N><M matrix switch 720B
`7
`.
`e inpu c anne
`is ransmi e across
`.
`.
`the MEMs 820A,
`the input channel 811As path is
`17545350 coupled to an output multiplexer 730 and an add port
`obstructed by micromirror 822 which is in an activated
`‘
`.
`.
`,
`t' Asddescrtibceid tttifi‘gttghtt emEodimgnt Of thebpresent Infin— 15 position. A front side 822a of micromirror 822 causes the
`10h 85C“ e m
`' may e use
`In com ma 10“ W1
`a
`in ut channel 811A to be redirected to dro channel 851B.
`linear network or a bi-directional ring. Dropping and adding
`ttAdditionall
`as the in utchanne181lAitstbein dro
`ed
`optical signals may be harried 01" independently by the
`the added chahtne1841Dtis being added. The addegd chteihnel
`$113101]. NXM :EltCh {)hittitrlceh 720? anCdlC720B Whightprogide
`originates from the add port 840 and is transmitted across the
`u to ient-cp d ghifi tth ty Since t et ah p0? an 7 :61 KS: 20 MEMs 820B until it is redirected by activated micromirror
`if: 1.23:ngding; each :tthmettr mpu C anne or Vt a e eng
`824. The micromirror 824 redirects the added channel 841D
`j
`.
`,
`.
`so that
`it
`intersects with an opposite side 8221) of the
`FIG 7 shows an example Of Operation Of the embodiment
`micromirror 822. The opposite side 822b of the reflecting
`described 1“ FIhG~ 6‘ in thls examcple, 35$th that: 1t tStiC;1t1ttIt\t
`mirror 822 redirects the channel 841D to the output channel
`to rep ace a c anne correspon mg to input c anne
`831A of the multi lexer 330.
`with a new channel corresponding to added channel 741C. 25
`As can be seenpfrom the example described above the
`AS described above, the input channel is received by the
`input channels 811B—811F will be transmitted across the
`demultiplexer 710. The demultiplexer divides the channels
`MEMs 820A and be received 1W the corresponding output
`thto rfispectivelmput channels 711,12AT71F that are then input
`channels 83IB—831F. The input channel 811A will be
`”“2; e 011:1“ SWhC 11:32:”; h 'fi MEM 720A f h
`“r dropped to the drop port 851B, while the added channel
`.
`can .e seen 1h.
`-
`’ t e.
`rst
`. 5
`0 t e 3“ 841D will be transmitted to the output port 831A.
`optical SWltCh matrix 102 receives the.
`input channels.
`Accordingly, the output multiplexer 830 will combine the
`:éiéhfzcrgfgglgotrhZlilllxtsstfifiseglsmihfefl1122;116:363:
`individutjil channels.into agoutp8u7t0signal and transmit it
`~
`’
`across I e transmission me ium
`.
`output channel 751B 9f the drop port 750' Additionally, as
`It should be appreciated that, in the embodiment of the
`can be seen, the remaining input channels 711B—711F are 35 present invention outlined in FIGS. 8 and 95 two sides of the
`permitted to pass across the first MEMS 720A WlthOht
`switching mirrors of the optical NxM switch matrix 820A
`tntgifhhtittzitriteous to the dropping of input channel 711A an
`tttc’ttjlci/[bttlt/[ttnly Oftltc Stdt’t ngttjtfg SthCttttélg Im/[irrors 0t tfic
`.
`.
`.
`>
`optic
`x
`sw1tc matrix
`are use .
`oreover, t e
`input Slghal 741C 15 added to the output channel 731Aby the
`structure shown in FIGS. 8 and 9 is strictly non-blocking. A
`add pctltth/[Zthttlt fizgfintbe Stttttfi
`:11
`tnleOIHlFFOF 724 o'f'the 40 new connection oraconnection change can be made without
`secon
`S
`15 SW1tC e
`111m an active P051t10h~
`rerouting the existing non-changing connections.
`Accordingly} thallgphtffifilnal 741-1C11s reldtireleted “773th:
`While this invention has been described in conjunction
`output por
`0
`e 0“ pu mu 1? exer .
`~
`with the exemplary embodiments outlined above, it is evi—
`Additionally, the output ports. 73113—7311: receive the input
`dent that many alternatives, modifications and variations
`channels 71113—7111”) respectively:
`.
`.
`45 will be apparent to those skilled in the art. Accordingly, the
`fThttt mttttttptexelt 7341:14623cflt‘tttttttes the antCOmblhafin
`exemplaig/ Zmbgdinfients of the invlention, as\set.forth 1above,
`o ou pu claune S
`—
`_ H10 an on 1111 srgna_.
`.16
`are inten e
`to e 1 ustrative, not
`imiting.
`arious c anges
`output Signal is then tranSInltth across the transmission
`may be made without departing from the spirit and scope of
`medium 770. Accordingly,
`the channel corresponding to
`the invention.
`input channel 711A has been removed from the transmission
`, What is claimed is:
`medium and the channel corresponding to added channel 5h
`1, An optical switching device, comprising:
`741C has been added in the removed channel’s place.
`an optical switch matrix having one or more optical
`It should be noticed that in the embodiment of the present
`switches that are capable of redirecting optical channels
`invention outlined in FIG. 6, only one side of the switching
`passing therethrough‘
`~
`~
`~
`mirrors is