UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`CISCO SYSTEMS, INC. AND OCLARO, INC.
`Petitioners
`
`v.
`
`OYSTER OPTICS, LLC
`Patent Owner
`____________
`
`IPR2017-02190
`Patent 6,476,952
`____________
`
`PETITIONERS’ REPLY
`
`
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`CISCO SYSTEMS, INC. AND OCLARO, INC.
`Petitioners
`
`v.
`
`OYSTER OPTICS, LLC
`Patent Owner
`____________
`
`IPR2017-02190
`Patent 6,476,952
`____________
`
`PETITIONERS’ REPLY
`
`
`
`IPR2017-02189
`
`I.
`II.
`
`TABLE OF CONTENTS
`Introduction ...................................................................................................... 1
`Ground 1: Claims 1-3 and 5 are Rendered Obvious over Bauch in view of
`Schneider ......................................................................................................... 3
`A.
`A POSITA would have been motivated to combine Bauch and
`Schneider ............................................................................................... 3
`The combination teaches altering the phase of the phase modulator
`(Claim 1[g]) .........................................................................................22
`The combination teaches rotating the phase imparted by the phase
`modulator by a predetermined amount (Claim 5) ...............................24
`III. Ground 2: Claim 4 is Rendered Obvious over Bauch in view of Schneider
`and Heflinger .................................................................................................26
`A.
`The combination discloses and teaches “an additional phase
`modulator” in an arm of the interferometer ........................................26
`PO has failed to assert a constitutional violation...........................................27
`
`B.
`
`C.
`
`IV.
`
`i
`
`
`
`1001
`
`1002
`
`1003
`
`1004
`
`1005
`
`1006
`
`1007
`
`1008
`
`1009
`
`1010
`
`1011
`
`1012
`
`1013
`
`1014
`
`1015
`
`1016
`
`IPR2017-02189
`
`LIST OF EXHIBITS
`
`U.S. Patent No. 6,476,952 to Snawerdt (“the ’952 Patent”)
`
`CV of Daniel Blumenthal
`
`Expert Declaration of Daniel Blumenthal
`
`U.S. Patent No. 6,826,371 to Bauch et al. (“Bauch”)
`
`Japanese Unexamined Patent Application Publication No. S61-127236
`by Tetsuya Kaneda et al. (“Kaneda”)
`
`Declaration Regarding English Translation of Kaneda
`
`English Translation of Kaneda
`
`Oyster Optics, LLC v. Cisco Systems, Inc. et al, Case No. 2:16-cv-
`01301-JRG, Complaint (E.D. Tex. Nov. 24, 2017) (Dkt. 1)
`
`Phase-Modulated Optical Communication Systems by Keang-Po Ho
`
`Digital Processing, Optical Transmission and Coherent Receiving
`Techniques by Le Nguyen Binh
`
`Coherent Optical System Design by Pieter W. Hooijmans
`
`Coherent Optical Communications Systems by Silvello Betti et al.
`
`N. M. Blachman, “The effect of phase error of DPSK error
`probability,” IEEE Trans. Commun., vol. COM-29, no. 3, pp. 364-
`365, 1981.
`
`G. Nicholson, “Probability of error for optical heterodyne DPSK
`system with quantum phase noise,’’ Electron. Lett., vol. 20, no. 24,
`1005-06 (1984)
`
`R. Wyatt, T. G. Hodgkinson et al., “DPSK heterodyne experiment
`featuring an external cavity diode laser local oscillator,” in Electron.
`Lett., vol. 19, no. 14, 550-52 (July 1983)
`
`S. Yamazaki et al., “1.2 Gbit/s optical DPSK heterodyne detection
`transmission system using monolithic external-cavity DFB LDs,” in
`
`ii
`
`
`
`IPR2017-02189
`
`1017
`
`1018
`
`1019
`
`1020
`
`1021
`
`1022
`
`1023
`
`1024
`
`1025
`
`1026
`
`1027
`
`1028
`
`1029
`
`Electron. Lett., vol. 23, no. 16, 860-62 (1987)
`
`S. Watanabe, T. Naito, T. Chikama, T. Kiyonaga, Y. Onoda, and H.
`Kuwahara, “Polarization-insensitive 1.2 Gb/s optical DPSK
`heterodyne transmission experiment using polarization diversity,”
`presented at ECOC’88 (Brighton, U.K.), vol. 1, 90-93 (1988)
`
`J. M. P. Delavaux et al., “1.4 Gbit/s optical DPSK heterodyne
`transmission system experiment,” 1988 Fourteenth European
`Conference on Optical Communication, ECOC 88 (Conf. Publ. No.
`292), Brighton, UK, 475-78 vol. 1 (1988)
`
`John R. Barry et al., Performance of Coherent Optical Receivers,
`Proceedings of the IEEE, Vol. 78, No. 8 (Aug. 1990)
`
`Eric. A. Swanson et al., “High Sensitivity Optically Preamplified
`Direct Detection DPSK Receiver with Active Delay-Line
`Stabilization,” IEEE Photonics Technology Letters, Vol. 6, No. 2
`(1994)
`
`U.S. Patent No. 6,559,996 to Miyamoto et al. (“Miyamoto”)
`
`U.S. Patent No. 5,543,952 to Yonenaga et al. (“Yonenaga”)
`
`Affidavit of Christopher Butler, Internet Archive
`
`Introduction to Logic Design, Second Edition, Sajjan Shiva (1998)
`
`U.S. Patent No. 6,396,605 to Heflinger et al. (“Heflinger”)
`
`U.S. Patent No. 6,700,907 to Schneider et al. (“Schneider”)
`
`U.S. Provisional Application No. 60/249,438 (“Schneider’s
`provisional application”)
`
`J. Salz, “Coherent Lightwave Communications”, AT&T Technical
`Journal, Vol. 64, No. 10 (Dec. 1985)
`
`Terumi Chikama et al., “Modulation and Demodulation Techniques in
`Optical Heterodyne PSK Transmission Systems,” Journal of
`Lightwave Technology, Vol. 8 No. 3 (1990)
`
`iii
`
`
`
`IPR2017-02189
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`1030
`
`1031
`
`1032
`
`1033
`
`1034
`
`1035
`
`1036
`
`1037
`
`1038
`
`1039
`
`1040
`
`1041
`
`Maryanne Heinbaugh, The Mach-Zehnder Coupler (August 27, 1997)
`(published thesis, Naval Postgraduate School) (on file with Calhoun
`Naval Postgraduate School Institutional Archive).
`
`K. P. Zetie et al., “How does a Mach-Zehnder Interferometer Work?,”
`Physics Education, Vol. 35, No. 1 (1999).
`
`Full-Text Comparison between the ’952 Patent and U.S. Patent No.
`6,469,816
`
`Full-Text Comparison between the ’952 Patent and U.S. Patent No.
`6,594,055
`
`U.S. Patent Publication No. 2003/0007216 to Chraplyvy et al.
`(“Chraplyvy”)
`
`Excerpts from the Prosecution History of the ’952 Patent
`
`Optical Fiber Telecommunications, Fourth Edition, Vol. B, Ivan
`Kaminow & Tingye Li (2002) (“Kaminow”)
`
`Edward I. Ackerman, “Broad-Band Linearization of a Mach-Zehnder
`Electrooptic Modulator,” IEEE Transaction of Microwave Theory and
`Techniques, Vol. 47, No. 12 (Dec. 1999)
`
`Technical Note, Using the Lithium Niobate Modulator: Electro-
`Optical and Mechanical Connections, Lucent Technologies (Apr.
`1998)
`
`Fundamentals of Photonics, First Edition, Bahaa E.A. Saleh & Malvin
`C. Teich (1991) (“Saleh”)
`
`S.J. Spammer & P.L. Swart, “Differentiating Optical-Fiber Mach-
`Zehnder Interferometer,” Applied Optics, Vol. 34, No. 13 (May 1995)
`
`Vijaya Poudyal & Mohcene Mezhoudi, Wavelength Sensitivity of
`Ti:LiNbO3 Mach-Zahnder Interferometer, Integrated Optics and
`Microstructures II, SPIE Vol. 2291 (Oct. 1994)
`
`1042
`
`Annotated Declaration of Keith W. Goossen
`
`iv
`
`
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`IPR2017-02189
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`1043
`
`Deposition Transcript of Keith W. Goossen
`
`1044
`
`Expert Declaration of Daniel Blumenthal, in support of Petitioners’
`Reply
`
`1045
`
`U.S. Patent No. 6,046,838 to Kou et al. (“Kou”)
`
`1046
`
`U.S. Patent No. 5,170,274 to Kuwata et al. (“Kuwata”)
`
`1047
`
`Edward Ackerman et al., “Bias Controllers for Phase Modulators in
`Fiber-Optic Systems,” Lightwave, Vol. 18, No. 5 (2001)
`
`1048
`
`Lightwave Homepage from archive.org (May 13, 2001)
`
`1049
`
`PSI Modulator Bias Controller, Photonic Systems, Inc. (2001)
`
`v
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`
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`IPR2017-02190
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`I. INTRODUCTION
`The Board instituted review on all grounds and all challenged claims (see
`
`Paper 09 (“DI”)). And all the issues raised in Patent Owner’s Response (Paper 14
`
`(“Resp.”)) do not withstand scrutiny. PO inexplicably devotes nearly thirty pages
`
`(Resp., 15-45) to confirming Petitioners’ expert testimony that Schneider
`
`“discloses MZ modulator 10 operating to modulate intensity.” Pet., 39; Ex. 1003,
`
`¶¶ 94-102. Those pages are essentially irrelevant to any material issue. Instead,
`
`the Board may focus on PO’s four substantive challenges: (1) it would not have
`
`been obvious to combine elements taught in Schneider and Bauch, as Dr.
`
`Blumenthal proposed (Ground 1) (Resp., 47-50); (2) using Schneider’s Mach-
`
`Zehnder Modulator (MZM) bias “control” would not “alter” the phase (Resp., 50-
`
`52); (3) claim construction for “rotating a phase imparted by the phase modulator
`
`by a predetermined amount” (claim 5) (Resp., 53-58); and (4) Heflinger does not
`
`teach an “additional phase modulator” (claim 4) (Resp., 58-64).
`
`PO’s challenge to Ground 1 principally contends that Schneider teaches
`
`away from using an MZM to modulate intensity to determine a bias and gain
`
`setting and then computing a different set of operational points for “open loop”
`
`control of the MZM to modulate phase, and that the use of “open loop” set points
`
`would not provide a reasonable expectation of success. Resp., 50. PO’s challenge
`
`fails, inter alia, because (a) as Dr. Blumenthal explained, the proposed
`
`1
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`
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`IPR2017-02190
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`combination would be a simple use of set point values obtained via Schneider’s
`
`closed loop algorithm; and (b) it is based on a premise that Schneider shows is
`
`false—that a POSITA would ignore Schneider’s teaching that the control loop may
`
`be turned off “for extended periods.” Ex. 1026, 6:34-35. PO’s second argument
`
`simply re-packages the first one and assumes that A POSITA’s use of Schneider is
`
`limited to modulating intensity. Again, PO’s challenge fails because it was known
`
`at the time that MZMs could be used to modulate intensity or phase. See, e.g.,
`
`Ex. 1029, 309-10, 314.
`
`PO’s third argument fails because its expert, Dr. Goossen, concedes that
`
`normal use of the phrase “rotating a phase” in the art includes rotating the phase of
`
`an arm by changing the DC bias voltage in prescribed adjustments, as explained by
`
`Dr. Blumenthal (Ex. 1003, ¶ 136-38), and because there is no basis to import
`
`limitations from the specification.
`
`PO’s fourth argument that the combination with Heflinger does not teach an
`
`additional phase modulator is misplaced because it is undisputed that Heflinger
`
`teaches an interferometer with a thermal heater that alters the length of an arm and
`
`thus changes the phase of the light in that arm, and because all evidence of how a
`
`POSITA would have understood that teaching shows that Heflinger discloses the
`
`claimed “additional phase modulator.” Petitioners’ obviousness challenge is
`
`supported by the asserted art, the testimony of Petitioners’ expert, and numerous
`
`2
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`
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`IPR2017-02190
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`supporting references indicative of a POSITA’s knowledge at the time.
`
`Accordingly, Petitioners’ challenge should succeed.
`
`II. GROUND 1: CLAIMS 1-3 AND 5 ARE RENDERED OBVIOUS OVER
`BAUCH IN VIEW OF SCHNEIDER
`A. A POSITA would have been motivated to combine Bauch and
`
`Schneider
`
`PO and Petitioners agree that Schneider discloses a Mach-Zehnder
`
`Modulator (MZM) operating to modulate intensity (see Pet., 39; Ex. 1003, ¶¶ 94-
`
`102; Ex. 2030, 113:4-20), that a POSITA could apply Schneider’s algorithm to
`
`settle at a quadrature point (e.g., Vπ/2) along the transfer function (see Ex. 2030,
`
`71:16-72:9, 85:4-6; 89:1-21; Resp., 25-26; Ex. 1043, 29:1-5), and that the transfer
`
`function of the MZM in Schneider is the same irrespective of whether the MZM
`
`modulates intensity or phase (see Pet., 39; Ex. 1003, ¶¶ 69-70, 102; Ex. 2030,
`
`92:13-18; Resp., 16-19; Ex. 2031, ¶¶ 29-32; Ex. 1043, 7:22-8:11, 145:2-10).
`
`Petitioners and its expert explained that Schneider’s algorithm is executed to
`
`derive information about the MZM’s transfer function, and then use that
`
`information to operate the MZM as either an intensity modulator or a phase
`
`modulator, and specifically as a phase modulator when implemented in Bauch’s
`
`system. Pet., 39-41; Ex. 1003, ¶¶ 94-102. PO’s principle contention is that a
`
`POSITA would not have used the information from Schneider’s control algorithm
`
`to operate the MZM as a phase modulator. Resp., 48. As explained below in
`3
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`IPR2017-02190
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`Sections II.A.1-5, a POSITA would have been motivated to combine Bauch and
`
`Schneider and would have had a reasonable expectation of success in doing so.
`
`1. The combination of Bauch and Schneider
`
`PO asserts that the Petition does not explain the combination of Bauch and
`
`Schneider. Resp., 48. However, the Petition and Dr. Blumenthal explained that a
`
`POSITA would have been motivated to combine Bauch and Schneider to use
`
`Schneider’s MZM, with its gain and bias control algorithm, as Bauch’s phase
`
`modulator so that the modulator would be stable and otherwise able to operate in
`
`“real world” conditions (e.g., noise, temperature, and aging), as disclosed in
`
`Schneider. Pet., 41; Ex. 1003, ¶¶ 90-103.
`
`The Petition and Dr. Blumenthal explain a POSITA’s knowledge about the
`
`operation of MZMs, e.g., that the same MZM component could be used to both
`
`modulate intensity and phase. Ex. 1003, ¶ 69; Ex. 1029, 309-10, 314; Ex. 1009,
`
`50. MZMs have a sinusoidal power transfer function (shown by the dashed line in
`
`the figure below):
`
`4
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`IPR2017-02190
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`Ex. 1003, ¶¶ 68-69 (annotating Ex. 1036, Fig. 16.3).
`
`a) An MZM is characterized by the Vπ value
`The MZM’s transfer function is a periodic sinusoid with a minimum,
`
`maximum, and period. Ex. 1044, ¶ 6. A quantity known as Vπ (labeled
`
`“minimum amplitude” above) corresponds to the point along the X-axis (1 on the
`
`graph above) where there is no intensity at the output (0 on the Y-axis). A
`
`POSITA would have understood that Vπ characterizes the transfer function. Ex.
`
`1044, ¶ 6; Ex. 1043, 10:18–22. Another quantity known as quadrature (e.g., Vπ/2
`
`or 3Vπ/2, labeled “quadrature operating point” above) corresponds to mid-points
`
`5
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`
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`IPR2017-02190
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`along the transfer function between full and no intensity.1 Id.; Ex. 1003, ¶¶ 69-71;
`
`Ex. 1010, 32; Ex. 1040, 1; Ex. 1049, 2; Ex. 1047, 2; Ex. 1045, 5:51-63, Fig. 2.
`
`b) An MZM would be biased at some function of the Vπ value
`based on modulation mode
`MZMs had DC bias control to change the DC operation point of the
`
`modulator to operate at different points along the transfer function. Ex. 1003,
`
`¶¶ 64-71; see Ex. 1038, 7, 9. A POSITA understood that the peaks (i.e., minimums
`
`and maximums) of the transfer function define points at which the output of the
`
`MZM is at a minimum or maximum intensity. Ex. 1003, ¶ 69.
`
`Against this backdrop, the Petition and Dr. Blumenthal explained the
`
`proposed combination: Bauch’s phase modulator is implemented using Schneider’s
`
`MZM and control circuit. Pet., 40-41. In the combination, a POSITA would have
`
`executed Schneider’s control algorithm and after execution is complete, a POSITA
`
`would have operated the same MZM to modulate phase in Bauch’s system. Pet.,
`
`1 PO suggests a narrow meaning of “quadrature.” Compare Resp., 26; Ex. 2031,
`
`¶ 40 with Ex. 2030, 36:17-37:13; Ex. 1003, ¶ 39. A POSITA would have
`
`understood that there are multiple quadrature points along a periodic transfer
`
`function. Ex. 1044, ¶ 6; Ex. 1049, 2; Ex. 1047, 2; Ex. 1045, 5:51-63, Fig. 2. Dr.
`
`Goossen rejected PO’s narrow meaning and agreed that “quadrature” is used more
`
`broadly in the art. Ex. 1043, 107:2-5, 158:10-18.
`
`6
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`IPR2017-02190
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`39-40, 68-69; Ex. 1003, ¶¶ 100-02, 136-37.
`
`Specifically, Schneider’s algorithm can be implemented to settle on a bias
`
`point at the quadrature corresponding to Vπ/2 on the x-axis of the graph above.
`
`Ex. 2030, 72:3-5 (“quadrature point associated with an intensity output power
`
`function”); Ex. 1043, 29:1-5 (confirming the same settling point).
`
`Schneider discloses that the “objective of the bias control loop is to derive
`
`the peak of the sinusoidal Mach-Zehnder function, where the derivative is zero”
`
`and that the gain control loop provides “the peak-to-peak swing of the electrical
`
`data signal output.” Ex. 1026, 5:18-23, 4:50-54. And Dr. Blumenthal explained
`
`that Schneider teaches to a POSITA to extract information about the transfer
`
`function from the settled point. Ex. 1003, ¶¶ 64-71, 87, 94-102; Ex. 2030, 48:3-
`
`49:9, 72:6-8; cf. Ex. 48:9-52:12, 95:18-23. Thus, a POSITA would have
`
`understood that Schneider teaches identifying or deriving the peak and peak-to-null
`
`swing associated with the transfer function based on the settled values of the
`
`control algorithm. Pet., 39, 69 (citing Ex. 1026, 5:18-23, 4:50-54); Ex. 1003,
`
`¶ 137; Ex. 2030, 48:3-49:9, 72:6-8; see also Ex. 1003, ¶¶ 64-71, 87, 94-102. For
`
`example, a POSITA could derive the peak of the transfer function (e.g., Vπ, which
`
`characterizes the transfer function) by multiplying the control voltages associated
`
`with the settled quadrature point (i.e., Vπ/2) by two and could derive the peak-to-
`
`null swing by using the same control voltages associated with the settled gain. Ex.
`
`7
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`IPR2017-02190
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`1044, ¶¶ 6-7.
`
`Using the derived peak and peak-to-null swing, Dr. Blumenthal explained
`
`specifically why it does not matter whether Schneider’s MZM operates to
`
`modulate data via intensity versus phase modulation. Pet., 69; Ex. 1003, ¶ 137;
`
`see, e.g., Ex. 1029, 310. He described how knowledge of the transfer function
`
`determined by the control algorithm can be used to operate the MZM to modulate
`
`intensity or phase. Ex. 1003, ¶¶ 96, 102. As shown below, a POSITA would have
`
`understood that in a DPSK system, the MZM would modulate phase by setting the
`
`DC bias to the minimum point (e.g., Vπ) and the gain such that the phase shift
`
`corresponds to 180 degrees relative to the input, or twice the peak-to-null swing
`
`(e.g., 2Vπ):
`
`8
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`IPR2017-02190
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`Ex. 1003, ¶¶ 70, 102. A POSITA would have set these points by first deriving the
`
`peak (e.g., Vπ) and peak-to-null swing (e.g., Vπ), and then simply multiplying the
`
`swing by two to arrive at the peak-to-peak swing (i.e., 2Vπ). Id. Alternatively, Dr.
`
`Blumenthal explains that because Schneider’s algorithm settles at a DC bias
`
`corresponding to Vπ/2 and a gain corresponding to Vπ, a POSITA could have
`
`multiplied each value by two (i.e., for the DC bias, Vπ/2 multiplied by two equals
`
`Vπ, and for the gain, Vπ multiplied by two equals 2Vπ) to arrive at the desired
`
`points for operating the MZM as a phase modulator.2 Ex. 1044, ¶ 7. Following
`
`2 Dr. Goossen admitted that a POSITA would understand this approach to work for
`
`9
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`IPR2017-02190
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`Schneider’s teaching of turning off the modulator control routine for extended
`
`periods, the Petition and Dr. Blumenthal explained that Schneider’s control
`
`algorithm may be periodically re-run to compensate for aging and temperature, and
`
`then powered down. Pet., 38-39, 68; Ex. 1003, ¶ 100-01, 136; Ex. 1026, 6:20-25.
`
`Thus, the modification proposed in the Petition and supported by Dr.
`
`Blumenthal’s explanation is simple and clear. As summarized above, both parties
`
`agree that Schneider discloses a MZM operating to modulate intensity, that
`
`Schneider’s algorithm settles at a quadrature point along the transfer function, and
`
`that the transfer function of Schneider’s MZM is the same irrespective of whether
`
`it modulates intensity or phase. In the proposed combination, Schneider’s control
`
`algorithm executes until it converges to derive information about the transfer
`
`function (i.e., peak and peak-to-null swing), for use in operating the MZM as a
`
`phase modulator in Bauch’s system. Dr. Goossen agrees that the combination
`
`would work for an ideal MZM, and only contends that it wouldn’t for a non-ideal
`
`one. And PO principally argues that Schneider must execute with closed-loop
`
`operation without disruption. But, as explained below, the combination teaches the
`
`closed-loop operation of Schneider’s algorithm that does not disrupt system
`
`operation and would also work for a non-ideal MZM.
`
`an ideal MZM. Ex. 1043, 10:12-17, 18:4-10, 50:9-13.
`
`10
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`2. Schneider’s algorithm executes using closed-loop operation
`
`and a POSITA would have expected success when implementing it
`
`in Bauch
`
`PO and its expert argue that Schneider is limited to what they deem “closed-
`
`loop control,” and thus, Schneider teaches away from biasing its MZM with
`
`parameters derived from the control routine. Resp., 27-28, 49-51. They contend
`
`that unlike open loop control, which “operates without regard to its output” (Resp.,
`
`28; Ex. 2031, ¶ 50), Schneider exclusively teaches closed-loop control, in which
`
`the control “is dependent on a measurement of its output.” Resp., 27; Ex. 2031,
`
`¶ 45. They further contend that Schneider is limited to operation dependent on
`
`direct, closed loop feedback control. Ex. 2031, ¶ 95. This is all beside the point.
`
`In the combination, the control loop and algorithm are still the exact same as
`
`disclosed in Schneider.
`
`PO and its expert fail to consider that in the proposed combination, a
`
`POSITA would have understood that when Schneider’s control algorithm executes,
`
`the control “is dependent on a measurement of its output” (i.e., closed-loop
`
`control). Specifically, the control algorithm settles at a converged point based on
`
`output measurements and input data with approximately an equal number of 0s and
`
`1s (e.g., “0101…”), and then the algorithm turns off. Ex. 1026, 3:25-31; Ex. 1044,
`
`¶ 8. Schneider explains that this works because its algorithm relies on the shape of
`
`11
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`IPR2017-02190
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`the transfer function and not specific values. Id., 2:38-39, 5:19-21, 5:50-53;
`
`Ex. 1027, 4-5; Ex. 1044, ¶ 8. As Dr. Blumenthal explained, a POSITA would have
`
`understood that Schneider runs its control algorithm in closed-loop operation,
`
`derives information about the transfer function (i.e., the peak and peak-to-null
`
`swing), and then uses the information derived from the settled point of the control
`
`algorithm to run the MZM as a phase modulator in Bauch’s system, in manner very
`
`similar to how Schneider uses the settled point to run the MZM as an intensity
`
`modulator. Ex. 1003, ¶ 94; Ex. 1044, ¶ 8. Thus, PO’s open-loop control argument
`
`is an irrelevant red herring.
`
`Indeed, PO’s binary view of control systems runs contrary to Schneider’s
`
`explicit disclosure of dis-continuous operation. Schneider discloses running its
`
`algorithm, and then powering it down once settled “for extended periods of time to
`
`save power.” Ex. 1026, 6:20-25, 6:36-38; see also Pet., 37-38; Ex. 1027, 4-6.
`
`Although PO did not address Schneider’s dis-continuous operation in its Response,
`
`Dr. Goossen admitted that Schneider teaches dis-continuation operation and
`
`explained that when Schneider’s control loop is powered down and running with
`
`fixed settings, there is no “control system anymore” (i.e., no closed or open
`
`control). Ex. 1043, 56:17-57:1, 149:19-150:15. In his view, running with fixed
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`settings is just “setting it.” Id., 147:20-148:14; see also 148:15-149:18. Thus,
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`even under Dr. Goossen’s view, Schneider is not limited to closed-loop control, as
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`it is not even a “control system” when using fixed settings.
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`It appears that PO’s and its expert’s actual argument is that Schneider
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`allegedly requires the values for controlling the MZM be taken directly from the
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`“settled” point. Ex. 1043, 123:2-9. This is incorrect for several reasons.
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`Schneider does not describe, let alone require direct values be taken from the
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`“settled” point in the algorithm. As explained above, Schneider teaches deriving
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`information about the transfer function (i.e., peak and peak-to-null swing) from the
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`settled values. Supra, Section II.A.1; Ex. 1026, 5:18-23, 4:50-54. And Dr.
`
`Goossen conflates taking the value directly from the settled point with PO’s
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`requirements that the algorithm run during data flow, and that no adjustment is
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`permitted after the control algorithm settles. Ex. 1043, 122:9-123:1 (expressing
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`narrow view that “all of the advantages that [Schneider] states” are specific to
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`“directly using … the operational output values”); Ex. 1043, 124:19-25; see also
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`Ex. 1043, 125:1-9, 126:21-127:3, 127:11-18. As explained in Sections II.A.3 and
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`II.A.5.a below, the combination does not disrupt system operation and Schneider
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`does not limit use of its derived values to the settling points of the control
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`algorithm.
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`Therefore, it is consistent with Schneider’s teachings to run Schneider’s
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`control algorithm periodically while not transmitting data, to configure the MZM
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`based on the derived information of the control algorithm (e.g., as a phase
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`IPR2017-02190
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`modulator), then to transmit phase-modulated data using the MZM.
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`3. The combination of Bauch and Schneider does not disrupt
`
`system operation
`
`PO and its expert argue that Schneider’s control algorithm must be run while
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`data is transmitted. Resp., 28, 49-51; Ex. 2031, ¶¶ 49, 97 (citing to Ex. 1027, 1).
`
`PO and its expert repeatedly assert a narrow view of Schneider predicated on data
`
`flow while the control algorithm executes. Resp., 28, 49-51; Ex. 2031, ¶¶ 46-49,
`
`97. But Schneider is not limited to operating its control algorithm during data
`
`transmission. Rather, Schneider teaches a goal of avoiding disruption of the
`
`system.
`
`As Dr. Blumenthal explained, “[s]ome systems stop data to do things and
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`there is not a problem.” Ex. 2030, 61:23-25. A POSITA would have understood
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`that Schneider’s control routine would be used periodically in a system (e.g., like
`
`Bauch) that can stop data transmission (e.g., for maintenance). In other words, a
`
`POSITA would have understood that Schneider’s description of “non-disruptive[]”
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`operation provides for acceptable levels of operation that were known in the art at
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`the time, and not absolute perfection. Ex. 1044, ¶¶ 8-10; Ex. 2030, 58:3-62:2;
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`Ex. 1026, 3:15-30, 4:44-54; Ex. 1027, 1.
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`A POSITA would have understood that in combination of Bauch, Schneider
`
`achieves this goal by reducing the impact of the gain and bias control routine on
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`IPR2017-02190
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`system operation, just as it does in Schneider alone. Id.; Ex. 2030, 71:6-9.
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`Schneider discloses the execution of a control algorithm on a microcontroller and
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`Schneider’s provisional acknowledges that the microcontroller is “self aligning”
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`and avoids “time consuming manual alignment techniques.” Ex. 1026, Abstract,
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`Fig. 2; Ex. 1027, 6. Indeed, Dr. Goossen found that Schneider’s bias control
`
`routine can settle in as few as four iterations. Ex. 2031, ¶ 77. A POSITA would
`
`have recognized that Schneider’s control algorithm could execute more quickly
`
`than the prior art bias control routines, limiting disruption to acceptable levels in
`
`the art. Ex. 1044, ¶ 9.
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`Moreover, Schneider discloses a control algorithm that settles, powers down,
`
`and re-runs periodically to compensate for temperature and aging. Ex. 1026, 3:25-
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`30. Dr. Goossen explained that temperature can drift on a daily basis and aging
`
`could drift over years. Ex. 1043, 52:19-53:9. In combination with Bauch, a
`
`POSITA would have understood that Schneider’s control algorithm would execute
`
`much more quickly than prior art systems, power down, and then re-run as needed
`
`for the desired level of Bauch. Ex. 1044, ¶ 9. Accordingly, a POSITA would have
`
`recognized that the combination achieves Schneider’s goal of avoiding disruption
`
`of the system and its data flow by reducing the impact of the gain and bias control
`
`routine on system operation. Id.
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`IPR2017-02190
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`4. PO’s remaining arguments similarly fail to show a lack of
`
`motivation to combine
`
`PO asserts several additional arguments that similarly fail to show a lack of
`
`motivation combine.
`
`a) Schneider does not limit its derived values to the settling
`points of the control algorithm
`PO and its expert assert that setting the DC bias and gain for an MZM to
`
`operate as a phase modulator amounts to “tuning or adjustment,” which Schneider
`
`purportedly seeks to avoid3. Resp., 28, 49-51; Ex. 2031, ¶ 97; see Ex. 1026, 2:14-
`
`15; Ex. 1027, 1.
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`However, Schneider does not limit its derived values to the settling points of
`
`the control algorithm. Nothing in Schneider restricts its application to intensity
`
`modulation, nor bars arithmetic operation on the values at which Schneider
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`3 Although PO asserts that operating Schneider’s MZM as a phase modulator
`
`requires computing a different set of operational points using “arbitrary offsets”
`
`that vary in “selection, time, or environment” (Resp., 49), Dr. Goossen admitted
`
`that this description in Schneider corresponds to components other than the
`
`modulator (i.e., MZM). Ex. 1043, 154:10-155:15. A POSITA would have
`
`understood that Schneider’s varying offsets are not unique to the Bauch
`
`combination because the same external control circuitry is used. Ex. 1044, ¶ 14.
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`16
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`IPR2017-02190
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`“settles.” Schneider’s algorithm itself provides for adjustment by setting the DC
`
`bias and gain based on the identified peak and peak-to-null swing along the
`
`transfer function. Ex. 1044, ¶¶ 7, 10; Ex. 1026, 5:19-21; Ex. 1027, 3. And it
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`remains undisputed that it was well known at the time that MZM could operate to
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`modulate intensity or phase. Ex. 1003, ¶ 102; see, e.g., Ex. 1029, 310, Fig. 2(b).
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`Dr. Blumenthal explained how to operate the MZM to modulate phase using the
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`knowledge of the transfer function determined by the control algorithm. Ex. 1003,
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`¶¶ 96, 102. A POSITA would have understood to set the DC bias to the minimum
`
`point (e.g., Vπ or twice the settled quadrature point) and the gain to 2Vπ (i.e., twice
`
`the derived peak-to-null swing). Id. Thus, a POSITA would have understood that
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`Schneider’s teaching of deriving peak and peak-to-null swing along the transfer
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`function applies to MZMs, irrespective of whether they are then used in a system
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`to modulate intensity or phase. See Ex. 1044, ¶ 6, 11.
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`Moreover, even if modifying the output of Schneider’s algorithm to operate
`
`the MZM as a phase modulator could be labeled as “additional adjustment and
`
`tuning,” this is not the type of additional adjustment and tuning Schneider seeks to
`
`avoid. Schneider’s provisional application explains that “[t]he invention allows for
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`a simple … control system which does not require tuning or adjustment”
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`(Ex. 1027, 4), and that previous methods required adjustment of control loops and
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`tuning of tone-based control circuits that were high-speed and data-rate dependent.
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`IPR2017-02190
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`Ex. 1026, 1:60-2:15; Ex. 1027, 5. Schneider discloses the “shortcomings of
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`conventional tone-based laser modulator control schemes … are effectively
`
`obviated by a microcontroller-based laser modulator control mechanism … .”
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`Ex. 1026, 2:10-15. This sort of additional adjustment and tuning is not required in
`
`the proposed combination. In combination with Bauch, Schneider’s MZM and
`
`control circuitry remain the same—no data-rate dependent components or tone-
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`based control is added. A POSITA would have understood that the combination
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`does not require the tuning and filter/isolation circuitry required by the prior art
`
`that Schneider notes. Ex. 1044, ¶ 10; Ex. 1026, 1:60-2:15.
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`b) The combination does not require inventive work
`PO asserts that Dr. Blumenthal had not evaluated the combination in which
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`Schneider’s control algorithm executes while the MZM transmits phase-modulated
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`data in Bauch’s system. Resp., 47. PO relies on its own misleading questions that
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`confusingly suggest a combination of executing the algorithm while transmitting
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`phase-modulated data—a combination that Dr. Blumenthal never discussed. See
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`Ex. 2030, 116:17-117:19. Petitioners do not argue such a combination. As Dr.
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`Blumenthal clarified on redirect, no inventive work is required for the proposed
`
`combination. Ex. 2030, 128:4-15. As explained above, the exact same control
`
`algorithm is used. Schneider’s algorithm is executed to derive information about
`
`the MZM’s transfer function based on the settled points, and then that information
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`is used to operate the MZM as a phase modulator in Bauch’s system.
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`IPR2017-02190
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`c) Schneider supports a system with minimal hardware
`PO suggests that Bauch cannot maintain its stated goal of providing minimal
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`hardware in combination with Schneider. Resp., 47-48. However, in the
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`combination, Schneider’s MZM itself merely replaces Bauch’s phase modulator,
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`and Schneider’s control circuitry “allows for extremely low power” and is readily
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`incorporated into existing MZMs used in systems, such as Bauch. Pet., 40;
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`Ex. 1003, ¶ 99; Ex. 1026, 3:29-30, 3:35-38, 3:60-67; Ex. 1027, 6. Accordingly, a
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`POSITA would have understood that Schneider supports a system with minimal
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`hardware. Ex. 1044, ¶ 13; Cf. Ex. 1026, 1:23-2:15, Fig. 1 (prior art).
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`d) A POSITA would have understood that Schneider’s control
`algorithm works for an ideal and non-ideal MZM
`PO and its expert assert a POSITA would not have configured Schneider’s
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`MZM as a phase modulator. Resp., 48-49; Ex. 2031, ¶ 97. Although not argued in
`
`P
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