Mail Stop “PATENT BOARD”
`Patent Trial and Appeal Board
`U.S. Patent & Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
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`UNITED STATES PATENT AND TRADEMARK OFFICE
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`BEFORE THE PATENT TRIAL AND APPEAL BOARD
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`FUJITSU NETWORK COMMUNICATIONS, INC.
`Petitioner
`
`v.
`
`CAPELLA PHOTONICS, INC.
`Patent Owner
`
`____________________
`
`Case IPR2015-00727
`Patent RE42,678
`____________________
`
`
`PATENT OWNER RESPONSE
`
`
`Patent Trial and Appeal Board
`U.S. Patent & Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
`
`
`
`
`
`
`
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`
`
`
`
`FUJITSU NETWORK COMMUNICATIONS, INC.
`Petitioner
`
`v.
`
`CAPELLA PHOTONICS, INC.
`Patent Owner
`
`____________________
`
`Case IPR2015-00727
`Patent RE42,678
`____________________
`
`
`PATENT OWNER RESPONSE
`
`
`
`IPR2015-00727
`U.S. Pat. No. RE42,678
`
`TABLE OF CONTENTS
`
`INTRODUCTION ........................................................................................... 1
`
`TECHNICAL BACKGROUND ..................................................................... 5
`
`I.
`
`II.
`
`A. Optical Networks Need Switches. ......................................................... 6
`
`B.
`
`C.
`
`D.
`
`E.
`
`F.
`
`To Increase Bandwidth, Modern Optical Networks Use
`Wavelength-Division Multiplexing (WDM)......................................... 7
`
`In WDM Networks, a Special Kind of Switch, Called an
`Optical Add-Drop Multiplexer (OADM), Is Used. ............................... 8
`
`Conventional OADMs Required Expensive and Bulky Optical
`Circulators to Properly Route Spectral Channels. ................................ 9
`
`Unlike Conventional OADMs, the Claimed Inventions Can
`Route Any Spectral Channel to Any of a Plurality of Output
`Ports. ....................................................................................................13
`
`The Examiner Properly Found the Claimed Inventions to Be
`Patentable Over Conventional OADMs. .............................................18
`
`III. CLAIM CONSTRUCTION ..........................................................................19
`
`IV. THIS IPR SHOULD BE TERMINATED AS TO ANY CLAIM
`THAT IS LATER CONFIRMED IN THE ’276 IPR. ...................................20
`
`V.
`
`FUJITSU FAILED TO SHOW THAT THE CHALLENGED
`CLAIMS ARE UNPATENTABLE. .............................................................23
`
`A. Grounds 5 and 7: A POSA Would Not Have Combined
`Bouevitch with Carr or Sparks. ...........................................................23
`
`1.
`
`2.
`
`The intentional misalignment taught by Carr and Sparks
`conflicts with Bouevitch’s principle of operation. ...................23
`
`Fujitsu’s proposed combinations are based on nothing but
`impermissible hindsight. ...........................................................31
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`- i -
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`Grounds 5 and 7: None of the applied references teach or
`suggest the claimed “ports.” ................................................................36
`
`B.
`
`1.
`
`2.
`
`The ’678 patent claims at least three ports; whereas
`Bouevitch has only two. ............................................................38
`
`Neither Carr nor Sparks teach or suggest ports configured
`to carry distinct sets of spectral channels..................................42
`
`C.
`
`Grounds 5 and 7: Dr. Ford’s Testimony is Based on Hindsight
`Reasoning and Bias .............................................................................43
`
`VI. DR. FORD’S DECLARATION TESTIMONY SHOULD BE
`GIVEN LITTLE, IF ANY, WEIGHT. ..........................................................45
`
`A.
`
`B.
`
`Capella Was Unable to Cross Examine Dr. Drabik on the Facts
`and Data that Underlie His and Now Dr. Ford’s Opinions. ................46
`
`Dr. Ford’s 2015 Declaration Testimony Conflicts with His Own
`2006 Peer-reviewed Paper. ..................................................................48
`
`VII. CONCLUSION ..............................................................................................49
`
`
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`- ii -
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`
`EXHIBIT LIST
`
`
`Reference
`U.S. Patent No. RE42,678 to Wilde et al.
`U.S. Patent No. 6,498,872 to Bouevitch et al.
`Prosecution History for U.S. Patent No. RE42,678.
`Joseph E. Ford et al., Wavelength Add-Drop Switching Using
`Tilting Micromirrors, 17(5) Journal of Lightwave Technology 904
`(1999).
`U.S. Patent No. 6,442,307 to Carr et al.
`U.S. Patent No. 6,625,340 to Sparks et al.
`U.S. Patent Publication No. 2002/0081070 to Tew.
`U.S. Provisional Patent Application No. 60/250,520 to Tew.
`U.S. Patent No. 6,798,941 to Smith et al.
`U.S. Provisional Patent Application No. 60/234,683 to Smith et al.
`J. Alda, “Laser and Gaussian Beam Propagation and
`Transformation,” in Encyclopedia of Optical Engineering, R. G.
`Driggers, Ed. Marcel Dekker, 2003, pp. 999–1013. (“Alda”)
`Joint Claim Construction and Prehearing Statement, Capella
`Litigation, Case No. 3:14-cv-03348-EMC, Dkt. 151.
`Newton’s Telecom Dictionary (17th ed. 2001) (excerpted).
`Fiber Optics Standard Dictionary (3rd ed. 1997) (excerpted).
`Webster’s New World College Dictionary (3rd ed. 1997)
`(excerpted).
`Declaration of Dr. Timothy Drabik.
`Curriculum Vitae of Dr. Timothy Drabik.
`U.S. Patent No. 6,253,001 to Hoen.
`U.S. Patent No. 6,567,574 to Ma et al.
`U.S. Patent No. 6,256,430 to Jin et al.
`U.S. Patent No. 6,631,222 to Wagener et al.
`U.S. Patent No. 5,414,540 to Patel et al.
`U.S. Patent Publication No. 2002/0097956.
`Shigeru Kawai, Handbook of Optical Interconnects (2005)
`
`Exhibit
`Number
`1001
`1002
`1003
`1004
`
`1005
`1006
`1007
`1008
`1009
`1010
`1011
`
`1012
`
`1013
`1014
`1015
`
`1016
`1017
`1018
`1019
`1020
`1021
`1022
`1023
`1024
`
`- iii -
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`
`Reference
`
`(excerpted).
`U.S. Patent No. 6,798,992 to Bishop et al.
`Joseph W. Goodman, Introduction to Fourier Optics, Second
`Edition, McGraw-Hill (1996).
`U.S. Patent No. 6,204,946 to Aksyuk et al.
`L.Y. Lin, “Free-Space Micromachined Optical Switches for
`Optical Networking, IEEE Journal of Selected Topics In Quantum
`Electronics,” Vol. 5, No. 1, pp. 4–9, Jan./Feb. 1999.
`S.-S. Lee, “Surface-Micromachined Free-Space Fiber Optic
`Switches With Integrated Microactuators for Optical Fiber
`Communications Systems,” in Tech. Dig. 1997 International
`Conference on Solid-State Sensors and Actuators, Chicago, June
`16-19, 1997, pp. 85–88.
`H. Laor, “Construction and performance of a 576×576 single-stage
`OXC,” in Tech. Dig. LEOS ’99 (vol. 2), Nov. 8–11, 1999, pp. 481–
`482.
`R. Ryf, “1296-port MEMS Transparent Optical Crossconnect with
`2.07 Petabit/s Switch Capacity,” in Tech. Dig. OSA Conference on
`Optical Fiber Communication, March 2001, pp. PD28-1–PD28-3.
`A. Husain, “MEMS-Based Photonic Switching in
`Communications Networks,” in Tech. Dig. OSA Conference on
`Optical Fiber Communication, 2001, pp. WX1-1–WX1-3.
`U.S. Patent No. 5,661,591 to Lin et al.
`H. Laor et al., “Performance of a 576×576 Optical Cross
`Connect,” Proc. of the Nat’l Fiber Optic Engineers Conference,
`Sept. 26-30, 1999.
`V. Dhillon. (2012, Sep. 18). Blazes and Grisms. Available:
`http://www.vikdhillon.staff.shef.ac.uk/teaching/phy217/instrument
`s/ph y217_inst_blaze.html. (“Dhillon”)
`Fianium Ltd. WhiteLase SC480 New Product Data Sheet.
`Available:
`http://www.fianium.com/pdf/WhiteLase_SC480_BrightLase_v1.p
`df. (“Fianium”)
`Declaration of Dr. Joseph E. Ford.
`
`Exhibit
`Number
`
`1025
`1026
`
`1027
`1028
`
`1029
`
`1030
`
`1031
`
`1032
`
`1033
`1034
`
`1035
`
`1036
`
`1037
`
`- iv -
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`
`Reference
`Curriculum Vitae of Dr. Joseph E. Ford.
`Patent Owner Response, Cisco Systems, Inc. v. Capella Photonics,
`Inc., Case IPR2014-01166, filed May 7, 2015.
`Clifford Holliday, Components for R-OADMs ’05 (B & C
`Consulting Services & IGI Consulting Inc. 2005). (“Holliday R-
`OADMs”)
`WavePath 4500 Product Brief, accessed at
`http://www.capellainc.com/downloads/WavePath%204500%20Pro
`duct%20Brief%20030206B.pdf. (“WavePath”)
`Cisco’s Renewed Motion and Memorandum in Support of Motion
`for Stays Pending Final Determinations of Validity by the Patent
`Office, Capella Photonics, Inc. v. Cisco Systems, Inc., Case No.
`14-cv-03348-EMC (N.D. Cal.), filed February 12, 2015. (“Cisco’s
`Mot. for Stay”)
`Order Regarding Cisco’s Pending Motion for Litigation Stay
`Pending Inter Partes Review, Capella Photonics, Inc. v. Cisco
`Systems, Inc., Case Nos. 14-cv-03348-EMC, 14-cv-03350, and 14-
`cv-3351 (N.D. Cal.), ordered March 3, 2015. (“14-cv-03348 Slip
`op.”)
`U.S. Patent No. 6,768,571 to Azarov et al. (“Azarov”)
`The Random House Dictionary of the English Language, 1987, pp.
`404, 742 (“Random House Dictionary”)
`Provisional Patent Application No. 60/267,285 (“’285
`provisional”)
`Transcript of Patent Trial and Appeal Board Conference Call for
`Cases IPR2014-01166 (merged with IPR2015-00816), IPR2014-
`01276 (merged with IPR2015-00894), IPR2015-00726, and
`IPR2015-00727, dated September 23, 2015.
`Transcript of Patent Trial and Appeal Board Conference Call for
`Cases IPR2015-00726 and IPR2015-00727, dated October 29,
`2015.
`Redline Comparison of Paragraph 166 of Drabik Declaration (Ex.
`
`Exhibit
`Number
`1038
`2001
`
`2002
`
`2003
`
`2004
`
`2005
`
`2006
`2007
`
`2008
`
`2009
`
`2010
`
`2011
`
`- v -
`
`
`
`Exhibit
`Number
`
`2012
`
`2013
`
`2014
`
`2015
`
`2016
`
`2017
`
`2018
`
`2019
`
`2020
`
`IPR2015-00727
`U.S. Pat. No. RE42,678
`
`Reference
`1016) and Ford Declaration (Ex. 1037)
`Provisional Patent Application No. 60/277,217 (“’678
`provisional”)
`John C. McNulty, A perspective on the reliability of MEMS-based
`components for telecommunications, Proc. SPIE 6884, Reliability,
`Packaging, Testing, and Characterization of MEMS/MOEMS VII,
`68840B (February 18, 2008)
`Capella Photonics Launches Dynamically Reconfigurable
`Wavelength Routing Subsystems, Offering Unprecedented
`Operating Cost Savings and Flexibility for Telecom Service
`Providers, Business Wire (June 2, 2003, 8:16 AM),
`http://www.businesswire.com/news/home/20030602005554/en/Ca
`pella-Photonics-Launches-Dynamically-Reconfigurable-
`Wavelength-Routing. (“Business Wire”)
`Benjamin B. Dingel & Achyut Dutta, Photonic Add-Drop
`Multiplexing Perspective for Next Generation Optical Networks,
`4532 SPIE 394 (2001). (“Dingel”)
`Tze-Wei Yeow, K. L. Eddie Law, & Andrew Goldenberg, MEMS
`Optical Switches, 39 IEEE Comm. I Mag. no. 11, 158 (2001).
`(“Yeow”)
`Patrick B. Chu et al., MEMS: the Path to Large Optical
`Crossconnects, 40 IEEE Comm. I Mag. no. 3, 80 (2002). (“Chu”)
`Clifford Holliday, Switching the Lightwave: OXC’s – The
`Centerpiece of All Optical Network (IGI Consulting Inc. & B & C
`Consulting Services 2001). (“Holliday OXC”)
`An Vu Tran et al., Reconfigurable Multichannel Optical Add-Drop
`Multiplexers Incorporating Eight-Port Optical Circulators and
`Fiber Bragg Gratings, 13 Photonics Tech. Letters, IEEE, no. 10,
`1100 (2001). (“Tran”)
`Jungho Kim & Byoungho Lee, Bidirectional Wavelength Add-
`Drop Multiplexer Using Multiport Optical Circulators and Fiber
`Bragg Gratings, 12 IEEE Photonics Tech. Letters no. 5, 561
`(2000). (“Kim”)
`
`- vi -
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`
`
`Exhibit
`Number
`2021
`
`2022
`
`2023
`
`2024
`
`2025
`
`2026
`
`2027
`
`2028
`2029
`
`2030
`
`2031
`2032
`
`2033
`2034
`
`IPR2015-00727
`U.S. Pat. No. RE42,678
`
`Reference
`Max Born & Emil Wolf, Principles of Optics (Pergamon Press, 6th
`Corrected Ed. 1986) (Excerpts). (“Born”)
`Fraine, D.S. Simon, O. Minaeva, R. Egorov, and A.V. Sergienko,
`Precise evaluation of polarization mode dispersion by separation
`of even- and odd-order effects in quantum interferometry, Optics
`Express v. 19, no. 21, 22820 (2011). (“Fraine”)
`Abdul Al-Azzawi, Fiber Optics: Principles and Practices (CRC
`Press 2006). (“Al-Azzawi”)
`Curriculum Vitae of Dr. Alexander V. Sergienko. (“Sergienko
`CV”)
`Ming C. Wu, Olav Solgaard and Joseph E. Ford, “Optical MEMS
`for Lightwave Communication,” Journal of Lightwave
`Technology, Vol. 24, No. 12, Dec. 2006, pp. 4433-4454.
`Deposition Transcript of Joseph E. Ford, Ph.D., Taken December
`11, 2015.
`Joseph E. Ford, et al., Interference-Based Micromechanical
`Spectral Equalizers, IEEE Journal of Selected Topics in Quantum
`Electronics, Vol. 10, No. 3, May/June 2004. (“Ford IEEE”)
`Prosecution History for U.S. Patent Number 6,625,346.
`Capella Photonics, Inc. v. Fujitsu Network Commc’ns, Inc.,
`Defendant’s Preliminary Invalidity Contentions, Case No. 1:14-cv-
`20531-PAS (S.D. Fl. May 19, 2014), D.I. 49.
`Capella Photonics, Inc. v. Cisco Sys., Inc., Defendant’s
`Preliminary Invalidity Contentions, Case No. 1:14-cv-20529-PAS
`(S.D. Fla. May 19, 2014), D.I. 39.
`U.S. Patent No. 6,178,284 to Bergmann, Ford, & Walker
`Timothy J. Drabik, Ph.D., The Press Democrat,
`http://www.legacy.com/obituaries/pressdemocrat/obituary.aspx?n=
`timothy-john-drabik&pid=176215170.
`Declaration of Dr. Alexander Sergienko.
`Joseph E. Ford, Ph.D., Hand Drawing, Exhibit No. 5 for
`Deposition of Joseph E. Ford, Ph.D., Taken December 11, 2015.
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`
`Exhibit
`Number
`2035
`2036
`2037
`2038
`
`Reference
`U.S. Patent No. 6,984,917 to Greywall & Marom.
`U.S. Patent No. 6,178,033 to Joseph E. Ford et al.
`U.S. Patent No. 6,859,573 to Bouevitch et al.
`J. E. Ford, Optical MEMS: Legacy of the telecom boom, Solid-
`State Sensor, Actuator and Microsystems Workshop, Hilton Head,
`SC, Jun. 6-10 (2004).
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`I.
`
`INTRODUCTION
`
`Capella Photonics, Inc. (“Capella”) was the first company to design and
`
`commercialize a reconfigurable optical add-drop multiplexer (“ROADM”) with 10
`
`fiber ports. This type of 10-ported ROADM later became known as a wavelength-
`
`selective switch and is protected by Capella’s U.S. Patent No. RE42,678 (“the ’678
`
`patent”), among others. Fujitsu Network Communications, Inc. (“Fujitsu”)
`
`petitioned for inter partes review (“IPR”) of the ’678 patent. The Board instituted
`
`trial on two grounds: (i) (Ground 5) claims 1, 9, 10, 13, 17, 19, 44, 53, 61, 64, and
`
`65 as allegedly obvious over Bouevitch and Carr under 35 U.S.C. § 103(a); and (ii)
`
`(Ground 7) claims 1-4, 19-23, 27, 29, 44-46, and 61-63 as allegedly obvious over
`
`Bouevitch and Sparks under 35 U.S.C. § 103(a).1
`
`
`1 Fujitsu proposed eight grounds: (Ground 1) claims 61-65 as allegedly
`
`anticipated by Smith under 35 U.S.C. § 102; (Ground 2) claims 61-65 as allegedly
`
`obvious over Smith and Tew under 35 U.S.C. § 103(a); (Ground 3) claims 1-4, 9,
`
`10, 13, 17, 19-23, 27, 29, 44-46, and 53 as allegedly obvious over Smith and Carr
`
`under 35 U.S.C. § 103(a); (Ground 4) claims 1-4, 9, 10, 13, 17, 19-23, 27, 29, 44-
`
`46, and 53 as allegedly obvious over Smith, Carr, and Tew under 35 U.S.C. §
`
`103(a); (Ground 5) claims 1, 9, 10, 13, 17, 19, 44, 53, 61, 64, and 65 as allegedly
`
`obvious over Bouevitch and Carr under 35 U.S.C. § 103(a); (Ground 6) 1, 9, 10,
`
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`The Board should confirm the instituted claims for at least four reasons.
`
`First, this IPR should be terminated in accordance with the estoppels that will
`
`attach in IPR2014-01276 (“the ’276 IPR”). Fujitsu was joined as a petitioner in
`
`that IPR. As a result, Fujitsu is now bound by that IPR’s estoppels. So, this IPR
`
`should be terminated as to every claim that is later confirmed in the ’276 IPR.
`
`Second, a person of ordinary skill in the art (“POSA”) would not have
`
`combined Bouevitch with either Carr or Sparks, because these combinations would
`
`defeat Bouevitch’s principle of operation and are based on nothing but
`
`impermissible hindsight. As an initial matter, Bouevitch’s system is designed as a
`
`symmetrical 4-f system that automatically corrects for any unintentional
`
`misalignment. Bouevitch describes this 4-f design as an “advantage” over the prior
`
`art. This advantage would be lost, however, if Bouevitch was combined with either
`
`Carr or Sparks, because both Carr and Sparks control power through intentional
`
`
`13, 17, 19, 44, 53, 61, 64, and 65 as allegedly obvious over Bouevitch, Carr, and
`
`Tew under 35 U.S.C. § 103(a); (Ground 7) claims 1-4, 19-23, 27, 29, 44-46, and
`
`61-63 as allegedly obvious over Bouevitch and Sparks under 35 U.S.C. § 103(a);
`
`and (Ground 8) claims 1-4, 19-23, 27, 29, 44-46, and 61-63 as allegedly obvious
`
`over Bouevitch, Sparks, and Tew under 35 U.S.C. § 103(a). The Board instituted
`
`trial on only Grounds 5 and 7, and denied all other grounds.
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`IPR2015-00727
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`misalignment. So, a POSA would not have combined Bouevitch with either Carr or
`
`Sparks.
`
`In addition to destroying Bouevitch’s principle of operation, a POSA would
`
`have had no reason—absent hindsight—to use either Carr’s or Sparks’s two-axis
`
`mirrors in Bouevitch’s system. Capella’s ’678 patent disclosed a new class of
`
`optical switches, which later became known as wavelength-selective switches. Yet
`
`Fujitsu and its experts2 improperly assumed that wavelength-selective switches
`
`were known when the ’678 patent was filed. And Fujitsu and Dr. Ford also rely on
`
`a rationale disclosed only in the ’678 patent itself as a motivation for combining
`
`Bouevitch with either Carr or Sparks. This is impermissible hindsight and is, by
`
`itself, a reason why the claims are patentable over the proposed combinations.
`
`Third, even if Bouevitch could be combined with either Carr or Sparks, none
`
`of these references discloses the claimed “ports” of the ’678 patent. These claims
`
`require at least three different collimator ports: “multiple fiber collimators,
`
`
`2 Fujitsu submitted two declarations in this IPR: one from the late Dr.
`
`Drabik; and one from Dr. Ford, who updated and signed on to Dr. Drabik’s
`
`declaration after Dr. Drabik’s unfortunate passing. Over Capella’s opposition, the
`
`Board allowed Dr. Ford’s declaration to be entered into this proceeding just three
`
`weeks before Capella’s Patent Owner Response was due.
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`IPR2015-00727
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`providing an input port . . . and a plurality of output ports.” Each of these ports is
`
`configured to carry a distinct set of spectral channels. Unlike these claims,
`
`Bouevitch’s system has only two collimator ports—which falls short of the three
`
`claimed ports. And neither Carr nor Sparks cures this deficiency because, unlike
`
`the claimed ports, Carr’s and Sparks’s ports are not configured to carry distinct sets
`
`of spectral channels. Instead, Carr and Sparks disclose output ports that carry the
`
`exact same signal as the input port. So, none of these references teaches or
`
`suggests the claimed ports.
`
`Fourth, Fujitsu’s IPR petition is based on hindsight bias. Fujitsu now relies
`
`on the declaration of Dr. Ford, after the unfortunate passing of its original expert,
`
`Dr. Drabik. As it turns out, Dr. Ford and Dr. Drabik were friends, and Dr. Ford
`
`testified that he agreed to be an expert here, at least in part, because he “wanted to
`
`know what [Dr. Drabik had] been doing” before his untimely death. Ex. 2026,
`
`47:5-48:2. But Dr. Ford did not spend any significant time re-reviewing the
`
`documents that formed the basis for Dr. Drabik’s original declaration. And Dr.
`
`Ford could not say where Dr. Drabik got many of the facts and data that were in
`
`his original declaration. So Dr. Ford’s testimony is inherently biased and based
`
`solely on hindsight reasoning.
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`For all these reasons and as described in more detail below, the challenged
`
`claims are patentable over the instituted grounds. These claims should, therefore,
`
`be confirmed.
`
`II. TECHNICAL BACKGROUND
`The ’678 patent is directed to switching and power control in optical-fiber
`
`networks. ’678 patent, 1:24-28, Abstract; Ex. 2033, ¶ 61. To perform these
`
`functions, the ’678 patent discloses dynamically reconfigurable optical add-drop
`
`multiplexers (“ROADMs”). Id. at 1:24-28; see also id. at Abstract, 5:1-5, 12:36-
`
`39. Unlike conventional OADMs, the inventive ROADMs of the ’678 patent
`
`include at least three fiber ports and an array of channel micromirrors that are
`
`pivotal about two axes and continuously controllable. See, e.g., id. at Abstract.
`
`ROADMs with these characteristics later became known as wavelength-selective
`
`switches. See Ex. 2025, Ming C. Wu, Olav Solgaard, Joseph E. Ford, “Optical
`
`MEMS for Lightwave Communications,” J. Lightwave Tech., vol. 24, no.12 (Dec.
`
`2006) at 4439 (“Ford’s 2006 Paper”). Using these structures, the claimed
`
`ROADMs or wavelength-selective switches can: (i) demultiplex an input signal
`
`into a plurality of spectral channels; (ii) route any spectral channel to any fiber
`
`port; and (ii) control the output power of each spectral channel. Conventional
`
`OADMs could not do this.
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`IPR2015-00727
`U.S. Pat. No. RE42,678
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`A. Optical Networks Need Switches.
`Optical fiber has become an integral component of modern
`
`telecommunications networks. Telecommunications companies use optical fibers
`
`to transmit telephone signals, Internet communications signals, and cable-
`
`television signals. Ex. 2033, ¶ 36. To route these signals to the appropriate
`
`location, fiber-optic networks include optical switches. These optical switches are
`
`located at hubs or nodes, where line segments of fiber-optic cable intersect. Id. at
`
`37-43.
`
`Conventional optical switches commonly had one or more beam-deflecting
`
`elements (e.g., mirrors) at the core of the switch. See, e.g., Ex. 1005, Carr at FIG.
`
`1B (mirrors 122); Ex. 1006, Sparks at FIG. 1 (mirror 16); Ex. 2033, ¶ 47. These
`
`beam-deflecting elements enabled the optical switches to route an input optical
`
`signal to a desired output. See, e.g., Carr, 1:64-67; Sparks, 4:15-32. The beam-
`
`deflecting elements could be made from micro-electromechanical systems
`
`(“MEMS”), although many people were initially skeptical about the reliability of
`
`these MEMS. See Ex. 2033, ¶ 55; Ex. 2026, Ford Tr. at pp. 106:21-107:10, 109:7-
`
`113:10, 114:21-118:17 (explaining that MEMS were originally deemed
`
`untrustworthy).
`
`One drawback of conventional optical switches was that they were
`
`broadband devices—i.e., they could only route the exact same signal that they
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`- 6 -
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`
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`received. See, e.g., Carr, 1:64-67; Sparks, 4:15-32; Ford’s 2006 Paper, 4433-4454,
`
`4433; Ex. 2033, ¶¶ 101; Ford Tr., 182:2-19, 184:19-186:2. A conventional optical
`
`switch could not break up an optical signal into its constituent wavelengths. As a
`
`result, a conventional optical switch, by itself, could not be used in wavelength-
`
`division multiplexing (“WDM”)—a technique used in modern optical-fiber
`
`networks, as explained in the next section.
`
`B.
`
`To Increase Bandwidth, Modern Optical Networks Use
`Wavelength-Division Multiplexing (WDM).
`
`Modern fiber-optics networks use WDM, which enables multiple data
`
`channels to be simultaneously transmitted on a single optical fiber. Ex. 1001, ’678
`
`patent, 1:37-42. Each data channel is made up of a unique wavelength of light. Id.
`
`So, these data channels are referred to as spectral channels. See, e.g., id. at 3:54-
`
`4:15. In WDM, each spectral channel is added to—or multiplexed onto—a single
`
`optical fiber. Id. at 1:37-42. As a result, WDM is beneficial because it significantly
`
`enhances the information bandwidth of the optical fiber. Id.
`
`That said, WDM is also problematic because it makes optical switching
`
`more complicated. Ex. 2033, ¶ 36. In a WDM network, each spectral channel must
`
`be individually routable to a desired location. Id. This routing cannot be
`
`accomplished with a conventional optical switch, because, again, a conventional
`
`optical switch can only route the exact same input signal that it receives; it has no
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`- 7 -
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`
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`ability to break an input signal into its constituent spectral channels and then
`
`individually route those spectral channels. See id. at 57, 100-01.
`
`To properly route WDM signals, conventional optical switches must be
`
`equipped with additional components (e.g., multiplexers and demultiplexers). See,
`
`e.g., Sparks, 4:9-14 (“[The disclosed optical switch] may be used to switch WDM
`
`signals as a group, or the WDM signals may be demultiplexed outside the switch
`
`and switched individually or as groups of channels if desired.”) (emphasis added).
`
`With these additional components, conventional optical switches can be
`
`transformed into optical add-drop multiplexers (OADM). See Ex. 2033, ¶¶ 39-40,
`
`52, 230.
`
`C.
`
`In WDM Networks, a Special Kind of Switch, Called an Optical
`Add-Drop Multiplexer (OADM), Is Used.
`
`The prevalence of WDM technology has made OADMs indispensable
`
`building blocks of modern fiber-optic networks. ’678 patent, 1:42-45. As the name
`
`suggests, an OADM can add one or more wavelengths onto an optical fiber,
`
`thereby inserting a new spectral channel into a data stream. Id. at 1:49-51; Ex.
`
`2033, ¶ 38. An OADM can also drop one or more wavelengths from an optical
`
`fiber, thereby removing one or more spectral channels from the data stream. ’678
`
`patent, 1:45-49; Ex. 2033, ¶ 38. As a result, an OADM makes it possible to add or
`
`drop spectral channels on an optical fiber without disrupting the overall data traffic
`
`on that fiber. ’678 patent, 1:51-55.
`
`- 8 -
`
`
`
`IPR2015-00727
`U.S. Pat. No. RE42,678
`D. Conventional OADMs Required Expensive and Bulky Optical
`Circulators to Properly Route Spectral Channels.
`
`Conventional OADMs had only two fiber ports that served as the input and
`
`output to the system. Ford’s 2006 Paper, pp. 4433-4454, 4438. These conventional
`
`OADMs also had (i) a diffraction grating for multiplexing and demultiplexing and
`
`(ii) MEMS mirrors for routing spectral channels to the fiber ports. Id. at 4438.
`
`Because conventional OADMs had only two fiber ports, the MEMS mirrors only
`
`had to switch between two states—one for each fiber port. See Id. at 4438 (“Each
`
`mirror defines a DWDM channel and, in switching, directs the reflected signal
`
`back along the input direction or tilted into a new path.”); Ford Tr., 188:19-189:7.
`
`Dr. Ford shows a conventional OADM in FIG. 11 of his 2006 paper—an
`
`OADM that Dr. Ford helped
`
`design. See Ford’s 2006 Paper,
`
`4438, FIG. 11; see also Ex. 1027,
`
`FIGS. 2, 4. During his deposition,
`
`Dr. Ford explained how this
`
`conventional OADM works.
`
`Specifically, he testified:
`
`Q. Okay. So the – let’s talk about the input on – on Fiber 1. The
`input as drawn goes upward; correct?
`. . .
`A. Correct.
`
`- 9 -
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`
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`Q. And after the input comes in, it’s going to go through the
`collimators and fold mirror; is that right?
`A. Actually, the Input 1 goes over the fold mirror.
`Q. Ah, so it just hits the grating.
`A. Goes straight to the grating.
`Q. Okay. And the grating, what that’s going to do, that’s a
`demultiplexer; right?
`A. A wavelength demultiplexer.
`Q. Okay. So, it’s going to break up the broadband signal into
`specific wavelengths?
`A. That’s right.
`Q. Okay. And after it hits the grating, it’s going to go through –
`the signal is going to go through the – what’s labeled in
`Figure 11 as “waveplate & focus lens”; is that right?
`A. That’s correct.
`. . .
`Q. After it goes through the focus lens, it’s going to hit those
`MEMS tilted mirrors; is that right?
`A. That’s correct.
`Q. Okay. And the mirror can switch between one of two states;
`right?
`. . .
`A. In this system, the mirror is switching between two states.
`Q. And the two states are either to go to Fiber 1 or Fiber 2;
`correct?
`A. The two states are so that the reflected signal ultimately goes
`to Fiber 1 or Fiber 2.
`
`- 10 -
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`
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`Ex. 2026, 187:6-189:7. So, this conventional OADM has only two fiber ports and
`
`digital MEMS mirrors that route spectral channels to one of those two fiber ports.
`
`Dr. Ford also explain that circulators are used on the two fiber ports to
`
`separate the signals at those ports. With respect to Fiber 1, Dr. Ford testified:
`
`Q. So from Fiber 1 there’s an input signal that goes in one
`direction and an output signal that goes in the opposite
`direction; correct?
`A. That’s correct.
`. . .
`Q. Okay. So in order to properly route the input and output
`signal, you have to stick a circulator on there; correct?
`. . .
`A. To separate the input from the output signal, you need to do
`something, but a circulator is the most convenient way to do
`that.
`Id. at 190:2-18. And with respect to Fiber 2, Dr. Ford testified:
`
`Q. Okay. So, again, in order to – so on Fiber 1 – I mean on
`Fiber 2, there’s an output signal going in one direction and
`an input signal going in the opposite direction; correct?
`A. That’s correct.
`Q. So in order to properly route or separate those signals, you
`have to do something, and one thing to do is put a circulator;
`right?
`. . .
`
`- 11 -
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`
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`A. I guess I would say that they have been routed. The
`circulator is used to separate them into separate fibers.
`Id. at 192:11-193:2. So, Dr. Ford explained, during his deposition, that optical
`
`circulators are attached to the two fiber ports to “separate the forward and reverse
`
`propagating signals” at those ports. Ford’s 2006 Paper, p. 4438.
`
`One of Dr. Ford’s patents—namely, U.S. Patent No. 6,204,946 (Ex. 1027,
`
`“Ford’s patent”)—and Bouevitch include examples of conventional two-state
`
`OADMs. See Ford Tr., 208:23-211:20 (describing the two-state OADM in the
`
`Ford’s patent), 217:5-218:24 (describing the two-state OADM in Bouevitch). Dr.
`
`Ford explained that because the OADMs in his patent and Bouevitch have only
`
`two fiber ports, optical circulators are required to separate the input and output
`
`signals at those ports. See id. at 212:15-216:14 (describing the optical circulators in
`
`Ford’s patent), 221:8-222:5 (describing the optical circulators in Bouevitch).
`
`Bouevitch, FIG. 11.
`
`
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`- 12 -
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`
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`The inventors of the ’678 patent realized that including optical circulators in
`
`an OADM was a significant drawback. See ’678 patent, 2:19-64. For example,
`
`these inventors criticized Ford’s patent’s circulator-based design, stating that this
`
`design’s need for circulators added optical loss, increased expense, and added
`
`complexity to the system. See id. at 2:40-64; Ex. 2012, ’678 provisional, p. 2. The
`
`inventors said:
`
`Although . . . Askyuk [sic, a.k.a. Ford’s patent] et al. has the
`advantage of performing wavelength separating and routing in free
`space and thereby incurring less optical loss, it suffers a number of
`limitations. First, it requires that the pass-through signal share the
`same port/fiber as the input signal. An optical circulator therefore has
`to be implemented to provide necessary routing of these two signals.
`Likewise, all the add and drop channels enter and leave the OADM
`through the same output port, hence the need for another optical
`circulator. [T]he optical circulators implemented in this OADM for
`various routing purposes introduce additional optical losses, which
`can accumulate to a substantial amount.
`’678 patent, 2:40-57.
`Given these limitations, one of the inventors’ goals was to design a ROADM
`
`that did not need optical circulators. See, e.g., id. at 3:22-26, 3:54-58, 6:17-20.
`
`E. Unlike Conventional OADMs, the Claimed Inventions Can Route
`Any Spectral Channel to Any of a Plurality of Output Ports.
`
`The ROADMs claimed in the ’678 patent are different than conventional
`
`OADMs. Unlike these conventional OADMs, the claimed ROADMs include, for
`
`- 13 -
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`
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`IPR2015-00727
`U.S. Pat. No. RE42,678
`example: (i) three or more fiber collimator ports;3 (ii) a diffraction grating for
`
`multiplexing and demultiplexing; and (iii) continuously controllable micromirrors
`
`to direct output spectral channels to any of the three or more output fiber
`
`collimator ports. Importantly, the claimed ROADMs do not require circulators.
`
`With these structures the claimed ROADMs could perform both switching and
`
`power control. ROADMs with these characteristics later became known as
`
`wavelength-selective switches. See Ford’s 2006 Paper, p. 4439 (characterizing
`
`wavelength-selective switches as having (i) three or more fiber ports, (ii) “analog”
`
`mirrors, and (iii) the ability to perform both switching and power control).
`
`By having more than two bidirectional ports, the ROADMs claimed in the
`
`’678 patent could be reconfigurable, sending a spectral channel to any one of a
`
`plurality of output ports. The ’678 patent describes the advantage of
`
`reconfigurability as follows: “By advantageously employing an array of channel
`
`micromirrors that are individually and continuously controllable, an OADM of the
`
`
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