('3) United States Patent
`(In) Patent NIL:
`US 6,928,244 B1
`Guldstein et al.
`(45} Date of Patent:
`Aug. 9, 2005
`
`
`
`
`U8006928244B|
`
`(54)
`
`(T5)
`
`SYSTEM AND METHOD OF WAVELENGTH
`AIMMIJROP MUIII‘IPLI‘LXING HAVING
`CLIENT CONFIGURABIIJ'FY
`
`inventors: Evan I.. Guldstein. Princeton. NJ {US};
`Lih-Yutin Lin. Little Silver. NJ (US):
`Chuan Pu. Midtllelown. NJ (US):
`Robert William Tknch. Little Silver.
`NJ (US)
`
`(73)
`
`Assignce: A'I'Sa'l‘ Corp. New York, NY (US)
`
`(‘l
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent
`is extended or adjusted under 35
`U.S.(‘. 1540013}! 513 days.
`
`(21)
`
`(22)
`
`(an)
`
`Appl. No; 09l722355
`Filed:
`Nov. 27, 200"
`
`Related [1.3. Application Data
`Provisional application No. ritl.-'l?2.?32. filed on Dec. 20.
`1000. and provisional application No. oft-"204.452. [lied on
`May Io. ZENII.
`Int. Cl.7
`
`
`
`LLS. (,l
`
`Field of Search
`
`. H04} MN"; 1104} 14t‘02;
`(H1213 6.26; (Hill? (1342
`............. 398l45; 3%;‘5I; 398.354;
`398.583; 385.: 1 T; 385.3 lit
`398545, SI. 54,
`398383, 82; 385.517, IS
`
`References Cited
`
`US. l’A'l'L-LN'I‘ DUCUMEN’I‘S
`
`
`5,58i.f143 A * 11-1905 Wu
`
`. 385:1?
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`[)uguu)‘
`03191}?
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`5.fi?],3tJ-1 .r‘\
`385M?
`tit-1098 .lungcrman el al.
`5.841.017 A ‘
`.. BRENT
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`fi.l44.?8] A ‘ {132000 Goldstein ct al
`.. 385.918
`(3.335.002 Bi ”
`t.-"2t]tt2
`Itala cl al.
`.. 383:1?
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`“355,61“! Bl
`*
`3:200}! Kapany .....
`
`9,2002 {‘rloeckncr et al.
`(1.445.841 Bl
`‘
`385.91?
`
`mourners It:
`‘ “£2002 l-‘eulc ct a].
`385,18
`
`6.510.060 Hi
`”
`2.52003 Liu .....................
`. 398.349
`
`" cited by examiner
`
`Primary l:'.rwuiner~——M. R. Sedighian
`
`(5?)
`
`ABS'I‘RAC'i'
`
`An optical carrier drop-"add transmiatsion system and method
`for adding a signal
`to multiplexed input optical signals
`conveyed he an optical multiplex input
`line. The multi-
`plexed input optical signals are dcniulliplexed to provide
`isolated input optical signals to an optical switch matrix
`comprising switches in an array of lines and columns, the
`isolaled inpul oplieal signals being inpulletl in a direction
`parallel to a line ofswitches in the optical switch matrix. 'Ilie
`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
`line is switched.
`
`10 Claims, 9 Drawing Sheets
`
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 1
`Exhibit 1033, Page 1
`
`

`

`U.S. Patent
`
`Aug. 9, 2005
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`Sheet 1 0f 9
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`US 6,928,244 Bl
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`
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`I
`
`DROPPORT
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`
`110
`
`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 2
`Exhibit 1033, Page 2
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`U.S. Patent
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`Aug. 9, 2005
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`Sheet 2 of 9
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`US 6,928,244 B1
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`ADDPORT
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 3
`Exhibit 1033, Page 3
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`

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`U.S. Patent
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`Aug. 9, 2005
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`Sheet 3 of 9
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`US 6,928,244 B1
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`ADDPORT
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 4
`Exhibit 1033, Page 4
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`

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`U.S. Patent
`
`Aug. 9, 2005
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`Sheet 401-9
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`US 6,928,244 B1
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`
`ADD PORT
`
`260
`
`270
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`
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`
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 5
`Exhibit 1033, Page 5
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`U.S. Patent
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`Aug. 9,2sz
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`Sheet 5 0f 9
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`US 6,928,244 Bl
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`410
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`SIGNAL MANAGER
`
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`CONTR
` 420
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`ADDED SIGNAL
`
`440
`
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`DROPPED SIGNAL
`PROCESSOR
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`DROP PORT
`
`114
`
`170
`
`Fig. 5
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`400
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 6
`Exhibit 1033, Page 6
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`

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`U.S. Patent
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`Aug. 9, 2005
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`Sheet 6 of 9
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`US 6,928,244 Bl
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 7
`Exhibit 1033, Page 7
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`U.S. Patent
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`Aug. 9, 2005
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`Sheet 7 of 9
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 8
`Exhibit 1033, Page 8
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`U.S. Patent
`
`Aug. 9, 2005
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`Sheet 301-9
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`US 6,928,244 B1
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`840
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`860
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 9
`Exhibit 1033, Page 9
`
`

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`U.S. Patent
`
`Aug. 9, 2005
`
`Sheet 901-9
`
`US 6,928,244 B1
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`mm
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`360
`
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`
`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 10
`Exhibit 1033, Page 10
`
`

`

`US 6,928,244 B]
`
`1
`SYSTEM ANI) METHOD OF WAVELENGTH
`ADDIDROP MULTIPLEXING HAVING
`CLIENT CONFIGURABILITY
`
`This non-provisional application claims the benefits of
`US. Provisional Application No.
`(“#119332 entitled
`"Wavelength addidrop Multiplexer With Client Config-
`urabitity" which was tiled on Dec. 20, 1999 and is hereby
`incorporated by reference in its entirety. The applicants of
`the provisional application are L-‘van L. Goldstein, Lih-Yuan
`Lin and Robert W.
`'l'kach.
`This non-provisional application also claims the benefits
`of US. Provisional Application No. 60304452 entitled
`"Micro-machined Optical AddlDrop Multiplexer With Cli-
`ent Configurability" which was filed on May to, 20(1) and
`is hereby incorporated by reference in its entirety. The
`applicants ol'the provisional application are Chuan Pu, Evan
`L. Goldstein, Lih-‘ifiian Lin and Robert W. 'lkach.
`
`BACKGROUND 01’ 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 goup of optical
`fibers. As the number of channels increase, so too does the
`need for an ability to add andi‘or drop a ponion 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 ancllor dropping 01" the signals can then he
`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-Uptical (0E0) conver-
`sion can he very complex, costly and time consuming.
`Additionally, optical wavelength addfdrop 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 0E0 conversions.
`l-Iowcver, currently available OADMs are generally fixed. In
`other words, a given incoming channel (wavelength) is only
`associated with a fixed addfdrop port. Such a device lacks
`"clicnt-configurabitity" and therefore severely limits the
`selection of which channels to addi’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 INVEN'I‘ION
`
`The invention provides an optical switch matrix device
`and methods that selectively add and drop channels from an
`
`2
`optical communication medium. The optical switch matrix
`can receive an input signal from an optical medium, such as
`an optical Ilber cable. The input signal can include numerous
`input channels, for example a plurality of channels each
`having a (Iilferent wavelength. The optical switch matrix can
`also receive an add signal which can include numerous add
`channels [or 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 the 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. Diderent front fixed optical wavelength addi’drop
`multiplexers {0ADMs} described in the related art,
`the
`invented optical switch matrix can be configured to allow
`each client to 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 addi’drop channels tolfrom 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 swuch matrix can addi’drop chan—
`nels tolfrom 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 ill" Till-Z DRAWINGS
`
`invention will be readily
`The benefits of the present
`appreciated and understood from consideration ol‘ 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 ditl'erent
`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 T are exemplary functional block diagrams of
`a wavelength add-drop device using MEMS technology in a
`iii-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
`[ii-directional network in accordance with the present inven-
`tion.
`
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`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 11
`Exhibit 1033, Page 11
`
`

`

`US 6,928,244 B]
`
`3
`DE’l'AlLL'l) DESCRIPTION 01" PREFERRED
`EMBODIMEN’I‘S
`
`FIG. 1 shows an oplical switch matrix system 100 for
`selectively adding and dropping channels from a transmis-
`sion medium 120. The system 101] includes an optical switch
`matrix 102 having four ports: input port 104, output port
`106, add port 108 and drop port 110. The input port 104 is
`optically coupled to a demultiplexer 112 for receiving input
`channels 104a—104ft'rom the transmission medium 120. The
`output port 106 is optically coupled to a multiplexer 114 for
`transmitting optical channels 106c—106f onto Ihe transmis-
`sion medium 120. The add port 108 is optically coupled with
`the optical switch matrix 102 for inputting added channels
`Hitler—1089 that are connected to different clients. The drop
`port 110 is optically coupled with the optical switch matrix
`102 for transmitting drop channels llOa—llfle, possibly for
`further prrxessing.
`130th the multiplexer 114 and the dcmultiplexer 112 are
`optically coupled with the transmission medium 120. The
`transmission medium 120 can include any structure that
`allows for
`the transmission of optical communication
`signaLs, such as an optical fiber. The optical communication
`signals can further include a plurality of. channels that are
`simultaneously transmitted along the communication
`medium 120. For example, numerous channels having dis-
`crete wavelengths can be combined onto a single optical
`transmission medium using wavelength-division-
`multiplexing [WDM}.
`is capable ol’
`'Ihe demultiplexer 112 is a device that
`optically dividing input signals received on the transmission
`medium 120 into a plurality of channels IMa—lfl-l-f. Once
`the input channel is divided, the input channels 104a—104f
`are transmitted to the optical switch matrix 102. As
`described above, the channels can travel along the transmis-
`sion medium 120 on difierent wavelengths. Additionally, the
`channels of the input signal can be combined on the trans-
`mission medium 120 according to any well known commu-
`nication technique, such as ’l‘DMA, CDMA and the like.
`Any technique that allows multiple channels to be transmit-
`ted across the transmission medium 120 and separated by
`the demultiplexer 112 can be used without departing from
`the spirit and scope of the present invention.
`The multiplexer 114 is a device that is capable ot'optically
`combining the output channels [Olin—10(1)r received from the
`optical switch matrix 102 into an output signal that is then
`transmitted on the transmission medium 120. As described
`above, the numerous output channels 106o—106f can travel
`along the transmission medium as an output signal
`in
`accordance with any known or later developed transmission
`technique without departing From the spirit and scope of the
`present invention.
`The add port 108 is a device that is capable of receiving
`channels lflRa—lflfle from dill‘erent clients, and then trans-
`mitting the added channeLs 108n—IOSc to the optical switch
`matrix 102. Data sources for the added channels 1030—1088
`can be generated by a plurality of light sources, such as
`tunable laser diodes, included in the add port 108. Each of
`the light sources can be adjusted to emit a channel having a
`specific wavelength. The light sources of the add port [08
`can further operate in accordance with instructions received
`from a controller [not shown) in order to selectively output
`an added channel of a specific wavelength. For example,
`added channels lBSa—lllSc can each be transmitted on
`different wavelengths hfi—Pt, corresponding to the wave-
`lengths of the input chance s.
`The drop port 110 is a device that is capable of receiving
`drop channels [ma-1109 from the optical switch matrix
`102. Each of the channeLs can be of various wavelengths.
`The drop port 110 can then output any ofthe drop channels
`to a processor (not shown) for further processing.
`
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`The optical switch matrix 102 is a device that is capable
`of redirecting optical signals passing through the optical
`switch matrix 102.
`in this manner, a portion ol‘ the input
`channels 1040—le can pass through the optical switch
`matrix 102 to the output channels lDtSa-lllfif without any
`substantial interference. in other words. these channels are
`permitted to pass nearly unabated through the optical switch
`matrix 102 and continue to travel on the transmission
`medium 121].
`
`Alternatively. a portion of the input channels can be
`selectively redirected to a drop channel 11041—1100 of the
`drop port 110 as the inputted channels 1040—le pass
`through the optical switch matrix 102. [n a similar manner,
`added channels 10811—1089 can be Selectively redirected to
`output channels 106a—106f of the output port 106 for which
`the corresponding input channel has been dropped as the
`added channels pass through the optical switch matrix 102.
`According to this technique, input channels can be removed!
`dropped and new channels can be added to the transmission
`medium 120.
`The optical switch matrix 102 can include an array of
`switches that can be in either an active or inactive state. in
`an active state, the switch is able to redirect a light beam or
`channel passing in close proximity to the switch.
`in an
`inactive state, the switch allows a light beam or channel to
`pass without incident.
`the optical
`As an example of operation, assume that
`switch matrix 102 includes at least NXM matrix ofswitches
`that are initially in the inactive position. Further assume that
`the transmission medium 120 is transmitting an input signal
`having 6 channels (A—l"). in the initial state, the input signal
`can be received by the demultiplexer 112. The demultiplcxer
`112 operates on the input signal to optically separate the
`input signal into input channels 1040—104f. The input chan-
`nels I04u—104f are then transmitted to the optical switch
`network 102.
`In the initial state ol‘ the switch matrix 102, where all of
`the optical switches are in the inactive state.
`the input
`channels 104n—104fare permitted to pass through the optical
`switch matrix to the output channel 1065:4061r without
`being acted upon. Accordingly,
`the output channels
`106e—106f, corresponding to the input channels 104a-104f
`are transmitted to the multiplexer 114. 'lhe multiplexer 114
`Ihen optically operates on the output channels [Elfin—106]" in
`order to combine the output channels 106n—1061r into an
`output signal, and then transmit the output signal back onto
`the transmission medium 120.
`During the course of operation. assume that it has now
`become desirable to replace input channel 104C with an
`added channel 1081). Accordingly. as the input channels
`IMH—leare transmitted through the optical switch matrix
`102, one or more optical switches in the path 01‘
`input
`channel 104C could be switched to an active state whereby
`the optical switch can redirect the light beam corresponding
`to input channel lNc to the specified drop port 110. such as
`dropped signal 1100. Furthermore,
`the add port 108 can
`begin transmitting an added signal 108th into the optical
`switch matrix 102 and an optical switch in the path of added
`channel 1085 could be switched to an active state, and
`thereby redirect the added channel 1081‘) to output channel
`106:: of the output port 106.
`Accordingly, the multiplexer would then receive the input
`channel 104:: on output channel 1061:, the input channel
`10413 on the output channel 106b, the added channel 108!) on
`the output channel 106c,
`the input channel 104d on the
`output channel 106d. the input channel 10% on the output
`channel 1069 and the input channel 104f on the output
`channel 1045f. The output channels 1060—106fwould then be
`combined by the multiplexer 114 and transmitted as an
`output signal across the transmission medium 120. In this
`
`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 12
`Exhibit 1033, Page 12
`
`

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`US 6,928,244 B]
`
`S
`manner, a channel of the input signal, 104C, has been
`replaced (dropped) during the addition of the added channel
`1015b.
`
`As is to he understood. thc switches of the optical switch
`matrix 220 can be changed at any time during operation to
`add or drop channels to or from the transmission medium
`120. In this manner, a user can easily configure the optical
`switch matrix 192 to add or remove all or a portion of
`information from an optical network.
`As shown in FIG. 2, the optical switch matrix 102 can he
`a single rnicroclectrical mechanical system {MEMs}. This
`single MEMS design of the optical switch matrix can be
`particularly useful for dropping and adding channels from an
`unidirectional ring network. The MEMs includes an array of
`micromirrors 280 that are rotatably mounted to a substrate
`282. The micromirrors 280 are rotatable between a non-
`activated and activated position.
`In the non-activated
`position, the micromirrors 280 are substantially parallel and
`flush with the substrate 282.
`In the active position,
`the
`micromirrors 230 are rotated or llipped to be in a substan-
`tially perpendicular position relative to the substrate 280.
`Furthermore, in the active position the micromirrors 280 ate
`positioned within the light path ofchannels passing through
`the optical switch matrix.
`This type of optical switch matrix is discussed in detail in
`Journal ofMicrrmfectm-mechom'cai' Systems, Vol. 5, No. 4,
`December 1996, entitled "Electrostatic Micro Torsion Mir-
`rors for an Optical Switch Matrix“ by I-liroshi 'l‘oshiyoshi
`and Hiroyuki Fujita, incorporated herein by reference in its
`entirety. The optical switeh matrix is also discussed in
`co-pending and commonly assigned patent application Ser.
`No. U9t‘003240 tiled on Dec. 31. 1997, also incorporated
`herein by reference in its entirety.
`As shown in FIG. 2. the wavelength add—drop device 200
`includes an optical N><M matrix switch 220 coupled to an
`input demultiplexer 210, an output multiplexer 230, an add
`port 240 and a drop port 25“.
`'lhe optical NxM matrix switch 220 can be a four-port
`matrix switch. In this embodiment, the optical NxM matrix
`switch 220 is a levl free space MEMS crossconnect that
`comprises NxM micromirrors 280.
`In the exemplary
`embodiment shown in FIGS. 2—4, N=o and M=5. As
`described above, each of the 30 micromirrors 280 shown in
`FIGS. H may take one of an active or inactive position.
`'Ibe positions of the micromirrors 280 can be controlled
`by a matrix controller (not shown in FIGS. 2—4). By ener—
`gizing the switch that is on the i”‘ row and the j'" column of
`the matrix switch, e.g., by flipping up the micromirror
`switch on line i and column j, and concurrently tuning the
`light source on 241} to the wavelength used on the im line.
`one can thus add a wavelength from light source 241} andt’or
`drop a wavelength at sensor 251}.
`Although the optical switch matrix 102 of FIG. 1 has been
`described in the exemplary embodiments of FIGS. 2-4 as
`being a MEMs type switch 220, it is to be understood that
`various other switches can he used without departing from
`the spirit and scope of the present invention. For example,
`the optical switch matrix 192 can be any type of optical
`switch with or without a micromechanical element, such as
`optical switches based on total
`internal
`reflection of a
`fluid—containing planar light wave circuit (PIE), otherwise
`known as bubble technology. Such technology is more fully
`described in the article entitled "Compact Optical Cross-
`Connect Switch based on Total Internal Reflection in a
`Fluid—Containing Planar Light Wave Circuit“ by .I. E.
`Fouquct. in 2000 OFC Technical Digest, pp. 204 to pp. 206.
`which is incorporated herein by reference in its entirety.
`Referring again to FIG. 2, as an example of operation,
`assume that
`in an initial state of operation, all of the
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`micromirrors 280 are in the inactive posit ion. Next, assume
`that a determination has been made that a signal conveyed
`by the input line 260 is to be dropped. ”so, it is determined
`on which line of the matrix the light ray that has the
`wavelength that carries the signal to be dropped is trans-
`mitted. Next, the sensor 251Ato 251M on which the signal
`is to be received is determined. The rnicrornirror 280 cor—
`responding to that line and the column of that selected sensor
`in the matrix is next positioned in the active position. Next,
`a determination is made whether another signal conveyed by
`the input line 260 has to be dropped. The above operations
`are repeated until no other signal conveyed by the input line
`260 has to be dropped.
`As mentioned above, since the NxM matrix switch in
`FIG. 2 is implemented in a unidirectional network, the add
`channels are always associated with the drop channels. That
`is, the add channel and drop channel on the same column are
`associated with the same client. By using the backside
`reflection of the activated micromirrors, and concurrently
`tuning the lasers of
`the add channels to selected
`wavelengths, signals can be added into traflic from the
`selected add channels.
`
`FIGS. 3 and 4 are exemplary functional block diagrams of
`the wavelength add—drop device of FIG. 2 in two difl'crent
`Functioning configurations corresponding to a same set of
`dropped light rays in a unidirectional network. In FIGS. 3
`and 4, the dropped light rays are the lights rays emitted by
`input ports 2113 and 211D, on the second and fourth lines
`of switch matrix 220. However, in the configuration outlined
`in FIG. 3, the light ray transmitted on the second line is
`dropped to the sensor 2511) and the light ray transmitted on
`the fourth line is dropped to the sensor 2513.
`In the
`configuration outlined in FIG. 4, the light ray transmitted on
`the second line is dropped to the sensor 251C and the light
`ray transmitted on the fourth line is dropped to the sensor
`251E.
`
`Consequently, in the configuration outlined in FIG. 3, the
`added signals are added by inputting light rays from the light
`sources 241]! and 24“). In the configuration outlined in
`FIG. 4, the added signals are added by inputting light rays
`from the light source 24IC‘ and 241E.
`FIGS. 3 and 4 show that the wavelength add-drop device
`according to an exemplary embodiment of the invention can
`be configured to select which sensor 251A-251E receives
`the dropped signal and to select the light source 24lA—241E
`that inpuLs the added signal.
`The present invention describes a device that olfers t'ull
`clicnt—conligurability. permitting any subset of the incoming
`wavelengths (l. 2, .
`.
`. N) to be added or dropped at any
`subset of the light sources 241A to 241E or sensors 251A to
`25115..
`
`An exemplary wavelength add-drop device 400 is out-
`lined in FIG. 5, and includes a signal manager 410, the
`optical NxM matrixswitch 102, the input demultiplexer 112,
`the output multiplexer 114, the add pon 108, the drop port
`111], the input line 160 and the output line 1'30.
`The signal manager 41'] comprises a dropped signal
`processor 420, a matrix controller 430 and an added signal
`processor 440. Tue dropped signal processor receives the
`signals output by the dropped channels llflawllfle of the
`drop port Ill] and processes those signals. The matrix
`controller 430 determines which micromirrors in the optical
`matrix switch 102 are to be rurned to their active position
`and commands the positions of the micromirrors. The added
`signal processor 440 provides the signals to he added
`through the add port 108 and the light sources INA—I085.
`The signal manager 410,
`the dropped signal processor
`420, the matrix controller 430 and the added signal proces-
`sor 440 may he,
`in the exemplary embodiment of the
`
`JDS UNIPHASE CORPORATION
`JDS UNIPHASE CORPORATION
`Exhibit 1033, Page 13
`Exhibit 1033, Page 13
`
`

`

`US 6,928,244 B]
`
`7
`invention shown in FIG. 5, a microprocessor that uses
`software to implement exemplary embodiments of the meth-
`ods and devices according to this invention.
`FIG. 6 shows a wavelength add-drop device 700 wherein
`the optical switch matrix 102 includes two optical NXM
`matrix switches 720A and 72015. This configuration of the
`optical switch matrix 102 having two MEMs can be par-
`ticularly useful for adding and dropping channels from a
`iii—directional ring network andtor a linear network. The
`optical NxM matrix switch 720A is coupled to an input
`demultiplexer 710, a drop port 750 and the optical NxM
`matrix switch 72013. The optical NxM matrix switch 7203
`is also coupled to an output multiplexer 730 and an add port
`740.
`Asdescribed above, the embodiment of the present inven-
`tion described in FIG. 6 may be used in combination with a
`linear network or a hi‘dircctional ring. Dropping and adding
`optical signals may be carried out
`independently by the
`optical NxM switch matrices 720A and 720]} which provide
`full clicnt—configurabiiity since the add port and the drop
`port associated with the same input channel or wavelength
`are independent of each other.
`FIG. 7 shows an example of operation of the embodiment
`described in FIG. 6. In this example, assume that it is desired
`to replace a channel corresponding to input channel 711A
`with a new channel corresponding to added channel 741C.
`As described above, the input channel
`is received by the
`demultiplexer 710. The demultiplcxer divides the channels
`into respective input channels TllA—TIF that are then input
`into the optical switch matrix 102.
`As can be seen in FIG. 7. the first MEMs 720A of the
`optical switch matrix 102 receives the input channels.
`Further, micromirror 722 has now been switched to an active
`state. Accordingly, the input channel 711A is redirected to 3
`output channel 7513 of the drop port 750. Additionally, as
`can be seen. the remaining input channels ‘TllB—‘tlllT are
`permitted to pass across the first MEMs 720A without
`interference.
`
`Simultaneous to the dropping of input channel 'i'llA, an
`input signal 741C is added to the output channel 731Aby the
`add port 740. As can be seen, a micromirror 724 of the
`second MEMs 72013 is switched into an active position.
`Accordingly,
`the input signal 741C is redirected to the
`output port 731A of the output multiplexer
`'i'30.
`Additionally, the output ports 73113—731l-' receive the input
`channels 7113—7111:, respectively.
`The multiplexer 730 then combines the new combination
`of output channchi 73lA—731F into an output signal. The
`output signal
`is then transmitted across the transmission
`medium 770. Accordingly,
`the channel corresponding to
`input channel 711A has been removed from the transmission
`medium and the channel corresponding to added channel
`741C has been added in the removed channel's place.
`It should be noticed that in the embodiment of the present
`invention outlined in l-‘lG. 6, only one side of the switching
`mirrors is used. Moreover, the structure shown in FIG. 6 is
`strictly non-blocking. In other words. a new connection or a
`connection change can be made without rerouting the exist-
`ing non-changing connections.
`FIG. 8 shows a wavelength add-drop device wherein the
`optical switch matrix 102 includes one optical NXM rnatrix
`switch 820A and one optical MxM switch 820B. The optical
`N><M matrix switch 820A is coupled to an input demulti-
`plexer 8l0, a drop port 850, the optical MxM matrix switch
`82013 and an output multiplexer 830. The optical MXM
`matrix switch 8208 is coupled to an add port 840.
`'lhe embodiment of the present
`invention described in
`l-‘lG. 8 may also be used in combination with a
`linear
`netwurk or a bi‘directionat ring network. Dropping and
`
`8
`adding optical signals may be carried out independently by
`the optical matrix switches 820A and 82015 which provide
`full client~conligurability since the add port and the drop
`port associated with the same input channel or wavelength
`are independent ot'each other due to the optical M><M matrix
`8208.
`FIG. 9 shows an example of operation ()Ithe embodiment
`described in FIG. 8. In this example, assume that it is desired
`to replace a channel corresponding to input channel 811A
`with a new channel, corresponding to the added channel
`841 D. As described above, the input signal is received by the
`demultiplexer 810 and separated into input channels
`(”IA—8111:. As the input channci 811A is transmitted across
`the MEMs 820A,
`the input channel SllA’s path is
`obstructed by micromirror 822 which is in an activated
`position. A front side 8220 of micromirror 822 causes the
`input channel 811A to be redirected to drop channel 851B.
`Additionally, asthe inpul channel SllAis being dropped,
`the added channel 841D is being added. The added channel
`originates from the add port 840 and is transmitted across the
`MEMs 8203 until it is redirected by activated micromirror
`824. The micromirror 824 redirects the added channel 84“)
`so that
`it
`intersects with an opposite side 822i) of the
`micromirror 822. The opposite side 822!) of the reflecting
`mirror 822 redirects the channel 8410 to the output channci
`831A of the multiplexer 830.
`As can be seen from the example described above, the
`input channels SllB-SllF will be transmitted across